微生物技术分子生物技术中英文资料外文翻译文献
微生物专题英文文献
班级：生物工程 学生：马春玲 2013年12月13日
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试验内容
1. Purpose and meaning 2. Introduction 3. Materials and methods
4.5 正交试验结果
Table 5. Results of ortho.1 Trend curve
Fig.2 Relationship between xylanase and time of fermentation in Aspergillus niger N212
通过对出发菌株注入不同剂量的氮离子，低能氮离子 束对菌体细胞均有一定程度的致死和损伤作用，细胞及其 损伤DNA又在其修复系统的作用下得到不同程度的修复， 从而导致黑曲霉孢子的存活率先下降，后上升，然后又下 降，并且菌种的修复出错会使其突变率大大提高，从而提 高了菌株的正突变率，从而确定了氮离子最佳注入参数。 以上试验可以得出最优培养基的组成（即各组分的最 适浓度），而且在以上培养得到了黑曲霉N212（表2），当 它发酵60个小时后酶活达到600IU/ml，比之前未优化的菌 株减少了12个小时，而且相对于原出发菌株酶活增加了100 ％。 试验证明离子注入对微生物进行诱变改良是一种行之 有效的诱变技术。
木聚糖酶是植物细胞壁的主要之一，属 于非淀粉多糖。可作为生物漂白剂用于造纸工 业，也可用于生物转化等等。目前木聚糖酶的 生产主要还依靠真菌。
对于产酶微生物的育种，国外多采用基因工程手段 构建高产菌，而国内多采用传统的诱变方法，如紫外辐 射、化学诱变剂处理等，这些诱变手段获得的突变株一 般稳定性差、容易产生回复突变且负突变较多及诱变选 育的工作量很大，而20世纪80年代末，人们发现离子束 可以引起靶物质原子移位和重排，使细胞表面刻蚀和穿 孔，并能影响和改变细胞电性等现象，提出了离子束可 以用于细胞加工和基因转移的设想，并陆续得到了研究 证实，由此产生了国内外普遍关注的离子束生物技术工 程学，而且离子束育种是一项具有我国自主知识产权且 被国际所承认的定向遗传改良的集物理诱变和化学诱变 于一身的综合诱变方法，具有损伤小、突变谱广、突变 率高的特点。
生物专业外语 文章翻译
Cytoplasm: The Dynamic, Mobile Factory细胞质：动力工厂Most of the properties we associate with life are properties of the cytoplasm. Much of the mass of a cell consists of this semifluid substance, which is bounded on the outside by the plasma membrane. Organelles are suspended within it, supported by the filamentous network of the cytoskeleton. Dissolved in the cytoplasmic fluid are nutrients, ions, soluble proteins, and other materials needed for cell functioning.生命的大部分特征表现在细胞质的特征上。
细胞质大部分由半流体物质组成，并由细胞膜（原生质膜）包被。
细胞器悬浮在其中，并由丝状的细胞骨架支撑。
细胞质中溶解了大量的营养物质，离子，可溶蛋白以及维持细胞生理需求的其它物质。
The Nucleus: Information Central（细胞核：信息中心）The eukaryotic cell nucleus is the largest organelle and houses the genetic material (DNA) on chromosomes. (In prokaryotes the hereditary material is found in the nucleoid.) The nucleus also contains one or two organelles-the nucleoli-that play a role in cell division. A pore-perforated sac called the nuclear envelope separates the nucleus and its contents from the cytoplasm. Small molecules can pass through the nuclear envelope, but larger molecules such as mRNA and ribosomes must enter and exit via the pores.真核细胞的细胞核是最大的细胞器，细胞核对染色体组有保护作用（原核细胞的遗传物质存在于拟核中）。
微生物英文文献及翻译—翻译
A/O法活性污泥中氨氧化菌群落的动态与分布摘要：我们研究了在厌氧—好氧序批式反应器（SBR）中氨氧化菌群落（AOB）和亚硝酸盐氧化菌群落（NOB）的结构活性和分布。
在研究过程中，分子生物技术和微型技术被用于识别和鉴定这些微生物。
污泥微粒中的氨氧化菌群落结构大体上与初始的接种污泥中的结构不同。
与颗粒形成一起，由于过程条件中生物选择的压力，AOB的多样性下降了。
DGGE测序表明，亚硝化菌依然存在，这是因为它们能迅速的适应固定以对抗洗涤行为。
DGGE更进一步的分析揭露了较大的微粒对更多的AOB种类在反应器中的生存有好处。
在SBR反应器中有很多大小不一的微粒共存，颗粒的直径影响这AOB和NOB的分布。
中小微粒（直径<0.6mm）不能限制氧在所有污泥空间的传输。
大颗粒（直径>0.9mm）可以使含氧量降低从而限制NOB的生长。
所有这些研究提供了未来对AOB微粒系统机制可能性研究的支持。
关键词：氨氧化菌（AOB），污泥微粒，菌落发展，微粒大小，硝化菌分布，发育多样性1.简介在浓度足够高的条件下，氨在水环境中对水生生物有毒，并且对富营养化有贡献。
因此，废水中氨的生物降解和去除是废水处理工程的基本功能。
硝化反应，将氨通过硝化转化为硝酸盐，是去除氨的一个重要途径。
这是分两步组成的，由氨氧化和亚硝酸盐氧化细菌完成。
好氧氨氧化一般是第一步，硝化反应的限制步骤：然而，这是废水中氨去除的本质。
对16S rRNA的对比分析显示，大多数活性污泥里的氨氧化菌系统的跟ß-变形菌有关联。
然而，一系列的研究表明，在氨氧化菌的不同代和不同系有生理和生态区别，而且环境因素例如处理常量，溶解氧，盐度，pH，自由氨例子浓度会影响氨氧化菌的种类。
因此，废水处理中氨氧化菌的生理活动和平衡对废水处理系统的设计和运行是至关重要的。
由于这个原因，对氨氧化菌生态和微生物学更深一层的了解对加强处理效果是必须的。
当今，有几个进阶技术在废水生物处理系统中被用作鉴别、刻画微生物种类的有价值的工具。
微生物英文文献及翻译—原文
微生物英文文献及翻译—原文本期为微生物学的第二讲，主要讨论炭疽和蛔虫病这两种既往常见而当今社会较为罕见的疾病。
炭疽是由炭疽杆菌所致的一种人畜共患的急性传染病。
人因接触病畜及其产品及食用病畜的肉类而发生感染。
临床上主要表现为皮肤坏死、溃疡、焦痂和周围组织广泛水肿及毒血症症状；似蚓蛔线虫简称蛔虫，是人体内最常见的寄生虫之一。
成虫寄生于小肠，可引起蛔虫病。
其幼虫能在人体内移行，引起内脏幼虫移行症。
案例分析Case 1：A local craftsman who makes garments from the hides of goats visits his physician because over the past few days he has developed several black lesions on his hands and arms. The lesions are not painful, but he is alarmed by their appearance. He is afebrile and his physical examination is unremarkable.案例1：一名使用鹿皮做皮衣的当地木匠来就医，主诉过去几天中手掌和手臂上出现几个黑色皮肤损害。
皮损无痛，但是外观较为骇人。
患者无发热，体检无异常发现。
1. What is the most likely diagnosis?Cutaneous anthrax, caused by Bacillus anthracis. The skin lesions are painless and dark or charred ulcerations known as black eschar. It is classically transmitted by contact with thehide of a goat at the site of a minor open wound.皮肤炭疽：由炭疽杆菌引起，皮损通常无痛、黑色或称为焦痂样溃疡。
微生物学术语双语（中英文）对照
微生物学术语双语（中英文）对照Brock Biology of Microorganisms Bilingual Glossary（For Internal Circulation Only）微生物学术语双语（中英文）对照北京林业大学生物科学与技术学院微生物教研室谢响明2007年6月10日Catalogue目录Chapter1 Microorganisms and MicrobiologyChapter 2 An Overview of Microbial LifeChapter 3 MacromoleculesChapter 4 Cell Structure/FunctionChapter5 Nutrition, Laboratory Culture, and Metabolism of MicroorganismsChapter 6 Microbial GrowthChapter 7 Principles of Microbial Molecular Biology Chapter 8 Regulation of Gene ExpressionChapter 9 Essentials of VirologyChapter 10 Bacterial GeneticsChapter 11 Microbial Evolution and Systematics Chapter 15 Microbial GenomicsChapter 18 Methods in Microbial EcologyChapter 19 Microbial Habitats, Nutrients Cycles Chapter 20 Microbial Growth ControlBilingual Glossary for MicrobiologyChapter 1Landmark：里程碑Ramifications：分支non-cellular life ：非细胞生命prion：朊病毒microbial diversity and evolution：微生物的多样性和进化pathogens：病原体genetic engineering：基因工程entity：实体macromolecules：大分子Reproduction：繁殖Differentiation：分化Communication：信息沟通coding devices：编码机制attributes：特征，品质coordination.：协调regulation：调节optimally attuned to最适地调和populations：种群habitat.：生境assemblages：集合体microbial communities：微生物群落biofilms：生物被膜hot springs：温泉Aquatic：水生的Terrestrial：陆生的Prokaryotic cells：原核细胞ecosystem ：生态系统biomass：生物量nitrogen：氮phosphorus：磷Bubonic Plague：鼠疫Fleas：跳蚤Mortality：死亡率Grotesque：奇异Liquefy：液化Influenza and pneumonia：流感和肺炎Tuberculosis：肺结核spontaneous generation：自然发生学说microbes：微生物Broth：肉汤Flask：烧瓶Guncotton filters：棉花滤器Dissolved：溶解的Ether：醚Particles：微粒flask with swan neck：曲颈瓶sterilization：灭菌vaccines：疫苗anthrax：炭疽热fowl cholera：禽流感rabies：狂犬病Germ theory：病菌说Koch’s postulates：科赫假设(法则) contagious diseases：传染病artificially infected animals：人工感染的动物Solid medium：固体培养基Gelatin：明胶Agar：琼脂Colony formation：菌落形成Differential staining：鉴别染色Pure culture：纯培养isolation：分离, 隔离inoculation：接种Tuberculin：结核菌素Diagnosis：诊断Subdisciplines：（学科的）分支enrichment culture：富集培养aerobic：需氧的N-fixing bacteria：固氮细菌sulfate-reducing：硫酸盐还原sulfur-oxidizing bacteria：硫氧化细菌root nodule：根瘤Lactobacillus：乳酸杆菌tobacco mosaic virus：烟草花叶病毒tenets：原则virology：病毒学nitrifying bacteria：硝化细菌nitrification：硝化作用oxidation of ammonia to nitrate：从氨氧化为硝酸盐hydrogen sulfide：硫化氰chemolithotrophy：无机化能营养型autotrophs：自养生物anaerobe ：厌氧生物Clostridium pasteurianum：巴斯德羧菌属Medical microbiology and immunology：医学微生物学和免疫学Aquatic microbiology：水生微生物学Microbial ecology：微生物生态学Microbial systematic：微生物的系统学Microbial physiology：微生物生理学Cytology ：细胞学Bacterial genetics：细菌遗传学Chapter 2Evolutionary History：进化史Elements：原理，基础Viral Structure：病毒结构The Tree of Life：生命树Physiological：生理学的Eukaryotic：真核的Cytoplasmic (cell)membrane：细胞质膜Cytoplasm：细胞质Macromolecules：大分子Ribosome：核糖体organic molecules：有机分子inorganic ions：无机离子rod-shaped prokaryote：杆状原核生物organelles：细胞器Archaea：古生菌Nucleus：细胞核（nuclear的复数）Mitochondrion （Mitochondrion复数）线粒体Chloroplast：叶绿体Metazoans：后生生物Cytoplasmic：细胞质的Membrane：膜，隔膜Endoplasmic reticulum：内质网Nucleoid：类核，拟核Nucleolus：核仁Nuclear：核的，细胞核Static：静态的metabolic abilities：代谢能力biosynthetic：生物合成genetic alterations：遗传改造Genomes：基因组Chromosome：染色体Circular：环状copy：拷贝haploid：单倍体extrachromosomal：染色体外的。
Microbiology 微生物学分类相关中英文对照
Microbiology 微生物学分类相关中英文对照微生物学microbiology病毒学virology噬菌体学bacteriophagology细菌学bacteriology鉴定细菌学determinative bacteriology系统细菌学systematic bacteriology真菌学mycology原生生物学protistology原生动物学protozoology普通微生物学general microbilogy微生物分类学microbial taxonomy微生物生理学microbial physiology微生物生物化学microbial biochemistry 微生物遗传学microbial genetics微生物生态学microbial ecology古微生物学paleomicrobiology土壤微生物学soil microbiology水生微生物学aquatic microbiology海洋微生物学marine microbiology悉生生物学gnotobiology医学微生物学medical microbiology兽医微生物学veterinary microbiology农业微生物学agricultural microbiology工业微生物学industrial microbiology石油微生物学petroleum microbiology食品微生物学food microbiology乳品微生物学diary microbiology瘤胃微生物学rumen microbiology诊断微生物学diagnostic microbiology病原学etiology国际微生物学会联合会International Union of Microbiological Societies, IUMS中国微生物学会Chinese Society for Microbiology, CSM世界培养物保藏协会World Federation for Culture Collection, WFCC中国微生物菌种保藏管理委员会China Committee for Culture Collection of Microorganisms,CCCCM美国模式培养物保藏所American Type Culture Collection, ATCC 自然发生说，无生源说spontaneous generation, abiogenesis原界urkingdom始祖生物progenote古始生物界archetista古细菌archaebacteria原生生物protista原生动物protozoan原生植物protophyte真核生物eukaryote原核生物prokaryote裂殖植物schizophyte微生物microorganism数值分类法numerical taxonomy模式目type order模式科type family模式属type genus模式种type species模式株type strain真菌fungi捕食真菌predacious fungi虫道真菌ambrosia fungi地下真菌hypogeal fungi虫生真菌entomogenous fungi 菌根真菌mycorrhizal fungi 木腐菌wood-decay fungi霉菌mold, mould半知菌imperfect fungi子囊菌ascomycetes粘菌slime mold, slime mould 壶菌chytrid卵菌oomycetes接合菌zygomycetes担子菌basidiomycetes核菌pyrenomycetes盘菌cup fungi块菌truffles锈菌rust fungi蘑菇mushrooms毒蘑菇poisonous mushroom酵母菌yeast无孢子酵母菌asporogenous yeasts 有孢子酵母菌sporogenous yeasts 黑粉菌smut fungi双态性真菌dimorphic fungi毛外癣菌ectothrix毛内癣菌endothrix完全真菌perfect fungi黑粉病smut disease锈病rust disease菌丝hypha菌髓trama假菌丝体pseudomycelium气生菌丝体aerial mycelium基内菌丝体substrate mycelium球拍状菌丝体racquet mycelium结节状菌丝nodular mycelium梳状菌丝pectinafe mycelium螺旋菌丝spiral mycelium匍匐菌丝stolon次生菌丝体secondary mycelium有隔菌丝septate hypha无隔菌丝nonseptate hypha生殖菌丝体reproductive mycelium 营养菌丝体vegetative mycelium不育菌丝体sterile mycelium菌丝体mycelium黄癣菌丝favic chandelier mycelium 产囊丝ascogenous hypha产囊体ascogonium原植体thallus粘菌体aethalium合胞体syncytium虫菌体hyphal body盾状体clypeus子实体fruiting body产孢体gleba子实层体hymenophore 子实层hymenium子实下层subhymenium 菌丝层subiculum菌丝段hyphal fragment 菌丝束coremium菌丝索funiculus菌核sclerotium器菌核pycnosclerotium 菌环annulus菌裙indusium菌盖pileus顶体apicle藏卵器oogonium雄器antheridium[锈菌]性孢子器pycnium锈子器aecium精子器spermogonium囊状体cystidium粉孢子梗oidiophore小梗sterigma接合孢子柄zygosporophore 孢囊柄sporangiophore配囊柄suspensor孢子梗sporophore分生孢子梗conidiophore雄器柄androphore帚状枝penicillus瓶梗phialide梗基metulae芽孔germ pore芽管germ tube芽缝germ slit孢丝capillitium周丝periphysis类周丝periphysoid侧丝paraphysis拟侧丝pseudoparaphysis类侧丝paraphysoid[孢子]外壁exosporium外生菌根ectomycorrhiza内生菌根endomycorrhiza内外生菌根ectendomycorrhiza泡囊丛枝菌根vesicular-arbuscular mycorrhiza 刺突spike弹丝elater刚毛seta微体microbody泡囊vesicle隔膜septum假隔膜pseudoseptum分生孢子盘acervulus分生孢子座sporodochium 精子团spermatium囊基膜hypothallus囊层基hypothecium囊层被epithecium囊间丝hamathecium囊托apophysis囊领collarette囊轴columella孔口ostiole菌托volva孢子角cirrus孢子球spore ball孢子印spore print聚簇cluster[菌丝]融合anastomosis [孢子]切落abjunction [孢子]缢断abstriction多态[现象] polymorphism 缢缩[作用] constriction 粉孢子oidium孢子spore掷孢子ballistospore厚壁孢子chlamydospore 环痕孢子annellospore节孢子arthrospore卷旋孢子helicospore腊肠形孢子allantospore孔出孢子porospore星形孢子staurospore线形孢子scolecospore砖格孢子dictyospore侧生孢子aleuriospore芽生孢子blastospore瓶梗孢子phialospore无梗孢子thallospore分生孢子conidium大分生孢子macroconidium 小分生孢子microconidium 节分生孢子arthroconidium 芽分生孢子blastoconidium 器孢子pycnidiospore无隔孢子amerospore双胞孢子didymospore多隔孢子phragmospore休眠孢子hypnospore顶生孢子acrospore顶生厚壁孢子fuseau内分生孢子endoconidium担孢子basidiospore双孢担孢子dispore同形孢子isospore柄生孢子stylospore[锈菌]性孢子pycniospore产雄器孢子androspore锈孢子aeciospore夏孢子urediniospore, aeciospore 冬孢子teliospore四分孢子tetraspore粘孢子myxospore多核孢子coenospore孢囊孢子sporangiospore子囊孢子ascospore多核细胞coenocyte分生孢子果conidiocarp分生孢子器pycnidium孢[子]囊sporangium柱孢子囊merosporangium四分孢子囊tetrasporangium原孢子囊prosporangium多核孢子囊coenosporangium 休眠孢子囊hypnosporangium 子囊ascus接合孢子zygospore拟接合孢子azygospore原囊壁子囊prototunicate ascus 单囊壁子囊unitunicate ascus 双囊壁子囊bitunicate ascus子囊果ascocarp子囊壳perithecium闭囊壳cleistothecium闭囊果cleistocarp盘状子囊果discocarp孢囊果sporangiocarp [接]合子zygote单性合子azygote多核合子coenozygote异形合子heterozygote合子核zygotonucleus游动合子planozygote担子basidium半担子hemibasidium隔担子heterobasidium无隔担子holobasidium有隔担子phragmobasidium 内生担子endobasidium原担子protobasidium上担子epibasidium下担子hypobasidium同担子homobasidium担子果basidiocarp担子体basidiophore配子gamete原配子progamete雄配子androgamete雄核发育androgenesis同形配子isogamete异形配子heterogamete游动配子zoogamete多核配子coenogamete配子囊gametangium配子母细胞gametocyte同形配子囊isogametangium 原配子囊progametangium 小孢子囊sporangiole微包囊microcyst足细胞foot cell脚胞foot cell固着器holdfast附着枝hyphopodium吸盘sucker锁状细胞clamp cell锁状联合clamp connection 偶核细胞zeugite卵球oosphere卵质ooplasm孢原质sporoplasm卵配子oogamete卵孢子oospore球状胞sphaerocyst子囊腔locule子囊盘apothecium子囊座ascostroma缝裂壳hysterothecium下子座hypostroma包被peridium子座stroma壳心centrum拟包被pseudoperidium无融合生殖apomixis同宗配合homothallism准性生殖parasexuality异宗配合heterothallism同配生殖isogamy异配生殖heterogamy无配生殖apogamy配囊交配gametangial copulation 交配型mating type全型holomorph夏孢子期uredostage冬孢子堆teleutosorus, telium 夏孢子堆uredinium子囊孢子形成ascosporulation 孢子形成sporulation细菌bacteria薄壁[细]菌类gracilicutes硬壁[细]菌类fermicutes疵壁[细]菌类mendosicutes无壁[细]菌类tenericutes柔膜细菌mollicutes真细菌eubacteria暗细菌scotobacteria无氧光细菌anoxyphotobacteria 生氧光细菌oxyphotobacteria 放线菌actinomycetes螺[旋]菌spirilla粘细菌slime bacteria。
分子生物学文献翻译
在旱地土壤中产甲烷古菌活性对养牛业的影响维维安radl1,5，安德烈亚斯gattinger1,5，艾莉卡时ˇ一´可娃´2,3，安娜NEˇmcova´2,3，Jiri Cˇuhel2,3，米洛斯拉夫的ˇimek2,3，让查尔斯munch1,4，迈克尔schloter4和Dana elhottova´21土壤生态学，慕尼黑工业大学，上施莱斯海姆，慕尼黑，德国；2生物中心，土壤生物学研究所，Cˇ艾斯克´不得ˇjovice，捷克共和国；3生物科学，南波西米亚州大学，Cˇ艾斯克´不得ˇjovice，捷克共和国；4gsf国家研究中心环境与健康，土壤生态，Neuherberg学院，德国。
在本研究中，我们测试的假设是动物的行走与作为越冬牧场土壤中的甲烷有机物有关。
因此，捷克共和国指出，在波西米亚南部的一个农场中，甲烷排放量和产甲烷菌种群对牛有不同程度的影响。
在春天，甲烷排放与动物影响的梯度相一致。
分析应用磷脂，该古细菌量最高的影响，发现部分（SI）对其有影响，其次是温和的影响（MI）没有影响。
对于产甲烷菌的实时显示甲基辅酶M还原酶（MCRA）基因的定量PCR分析观察到了相同的趋势。
检测单不饱和脂肪酸异戊烯基侧链的碳氢化合物（i20:1）表示的乙酸分解的存在影响牛产甲烷菌。
这个结果是由mcrA基因序列分析证实得到的，这表明，所分析的克隆的33%属于甲烷。
克隆序列的大部分（41%）与未培养瘤胃有关。
由此可得到的假设是，相当大的一部分来自放牧本身产生甲烷的区域。
相比于春天采样，在秋天，古细菌的生物量和mcrA数显著减少主要用于截面MI基因观察。
可以得出结论，5个月后没有牛的影响，严重影响了部分保持其产甲烷的潜力，而在温和的冲击后甲烷生产潜力。
期刊名称（2007）1，443，452–；DOI: 10.1038/ismej.2007.60；网上公布19七月2007学科类别：微生物生态学和自然栖息地的功能多样性关键词：多样性；甲烷排放；甲基辅酶M还原酶引言农业对于在土壤和植物生物量的二氧化碳（OCA，2006）气体减排和系统隔离提供了巨大的潜力。
关于微生物的英文作文
关于微生物的英文作文Microorganisms: The Hidden World Within.Microorganisms, the tiniest of living organisms,inhabit every conceivable environment on Earth, from the depths of the ocean to the high-altitude atmosphere. Despite their diminutive size, microorganisms play an indispensable role in the functioning of our planet, influencing everything from the cycling of nutrients to the regulation of the climate.Types of Microorganisms.The vast array of microorganisms can be classified into three main types: bacteria, archaea, and protists. Bacteria are single-celled organisms with a simple cell structure, lacking a nucleus or membrane-bound organelles. Archaea, once classified as bacteria, are now recognized as a distinct group with unique cell structures and genetic makeup. Protists, on the other hand, represent a diversegroup of eukaryotes, characterized by a membrane-bound nucleus and more complex cell structures.Diversity and Distribution.The diversity of microorganisms is staggering, with an estimated 10 million to 1 trillion species existing on Earth. They occupy an incredible range of habitats, from extreme environments like hot springs and acid lakes to the bodies of plants, animals, and humans. Microorganisms are found in soil, water, air, and even on the surface of rocks. Their ubiquitous presence underscores their adaptabilityand resilience.Role in Nutrient Cycling.Microorganisms play a crucial role in the cycling of nutrients, including carbon, nitrogen, and phosphorus,within ecosystems. Bacteria and fungi decompose organic matter, breaking down complex molecules into simpler ones that can be taken up by plants. Nitrogen-fixing bacteria convert atmospheric nitrogen into a form that can be usedby plants, a process essential for maintaining soil fertility.Ecological Impact.Microorganisms significantly impact various ecosystems. They are primary producers in many food chains, generating organic matter through photosynthesis or other metabolic processes. Microorganisms also participate in biodegradation, breaking down pollutants and contributing to waste decomposition. Additionally, they influence symbiotic relationships with other organisms, providing nutrients or protection in exchange for shelter or other benefits.Human Health.Microorganisms exert complex effects on human health. Some bacteria, viruses, and protists are pathogenic, causing diseases such as pneumonia, influenza, and malaria. However, many microorganisms also contribute to our well-being. The human microbiome, a vast community ofmicroorganisms residing in and on our bodies, aids in digestion, immune function, and disease resistance.Industrial and Agricultural Applications.Microorganisms have numerous industrial andagricultural applications. Bacteria and fungi are employed in the production of pharmaceuticals, enzymes, and antibiotics. They are also used in the fermentation of food and beverages, such as cheese, yogurt, and beer. In agriculture, microorganisms enhance soil health, improve plant growth through nitrogen fixation, and protect plants from pests and diseases.Environmental Issues.While microorganisms offer many benefits, they can also pose environmental challenges. Harmful algal blooms, caused by excessive growth of algae, can produce toxins that contaminate water supplies and harm aquatic life. Microbial pollution in drinking water systems can lead to waterborne diseases. Furthermore, the release of greenhouse gases bymicroorganisms contributes to climate change.Future Perspectives.Ongoing research continues to illuminate the intricate world of microorganisms. Advancements in sequencing technology have enabled scientists to explore the vast diversity of microorganisms and their role in various environments. Studying microorganisms holds great potential for discovering new antibiotics, developing sustainable agricultural practices, and mitigating the impact of climate change.Conclusion.Microorganisms are the unseen architects of our planet, playing a crucial role in the functioning of ecosystems, influencing human health, and contributing to industrial processes. Their diversity and adaptability have shaped the history of life on Earth and continue to impact our present and future. As we delve deeper into the hidden world of microorganisms, we gain a greater appreciation for theirprofound significance and the interconnectedness of all living organisms.。
微生物文献翻译
微生物文献翻译张宇生物科学2011031021Ethanol, isopropanol, and 1-butanol are the only naturally produced alcohol biofuels. Isopropanol can be used directly as a fuel supplement to gasoline or as a feedstock for the transesterification of fats into biodiesel [35]. Both isopropanol and 1-butanol are produced in a mixed product fermentation in various strains of Clostridium [36], with maximum production levels reaching 2 g/L and 20 g/L, respectively [37, 38]. With a renewed interest in alternative fuels, the production of isopropanol and 1-butanol has been recently investigated in genetically tractable heterologous organisms. These organisms, such as Escherichia coli and Saccharomyces cerevisiae, facilitate the design and optimization of new biofuels processes by combining an increasing synthetic biology toolbox with a well-studied metabolism. Isopropanol production in E. coli has surpassed that of Clostridium by assembling the pathway for acetone production and a secondary alcohol dehydrogenase [8, 12]. The production of 1-butanol, however, has proven to be more difficult. Initial efforts were able to produce ~0.5 g/L using E. coli as a host [7]. Construction of a new strain harboring a single construct resulted in an increase in production to 1.2 g/L [9]. In addition to E. coli, 1-butanol production has been investigated in Pseudomonas putida, Bacillus subtilis, and S. cerevisiae [10, 11], although production in E. coli has thus far shown the most promise. Each ofthese processes, however, is far from industrial feasibility, as yields (~0.05 g/g) and productivities (~0.01 g/L/h) must increase significantly to match the same figures for corn ethanol (~0.5 g/g and 2 g/L/h). The advancement of these processes is thought to be limited by the low activity of pathway enzymes due to poor expression, solubility, or oxygen sensitivity, as well as the metabolic imbalance introduced by these heterologous pathways. While productivity in each of these platforms is low in comparison with Clostridial fermentation, the ability to engineer and manipulate these user-friendly hosts will facilitate the development of these processes.翻译：唯一的自然生产的酒精燃料乙醇、异丙醇、和1-丁醇。
微生物专业名词英文小作文
微生物专业名词英文小作文Microbiology is the study of microorganisms, which are tiny living organisms that are invisible to the naked eye. These microorganisms include bacteria, viruses, fungi, and protozoa. Microbiology is a broad field that encompasses many different areas of study, including medical microbiology, environmental microbiology, and industrial microbiology.Medical microbiology focuses on the study of microorganisms that cause disease in humans. This includes the study of bacteria and viruses that cause infections, as well as the development of vaccines and other treatments to combat these pathogens. Medical microbiologists also study the role of microorganisms in the human microbiome, whichis the collection of microorganisms that live in and on our bodies and play a crucial role in our health.Environmental microbiology, on the other hand, focuses on the study of microorganisms in the environment. This includes the study of how microorganisms impact the health of ecosystems, as well as their role in processes such as nutrient cycling and bioremediation. Environmentalmicrobiologists also study the use of microorganisms in environmental monitoring and pollution control.Industrial microbiology is the application of microorganisms in industrial processes. This includes the use of microorganisms in the production of food and beverages, the synthesis of pharmaceuticals, and the production of biofuels. Industrial microbiologists also study the use of microorganisms in waste treatment and the development of new biotechnologies.Overall, microbiology is a diverse and exciting field that plays a crucial role in many aspects of our lives. From understanding the causes of infectious diseases to developing new ways to produce sustainable energy, microbiology has the potential to make a significant impact on our world.微生物学是研究微生物的学科，微生物是一种肉眼无法看到的微小生物。
生物相关专业外文文献（有翻译好的版本）
生物相关专业外文文献（有翻译好的版本）Ecological Engineering 12 1999 27–38 Combining constructed wetlands and aquatic andsoil lters for reclamation and reuse of waterCH House BA Bergmann AM Stomp DJ FrederickDepartment of Forestry North Carolina State Uniersity Box 8008 Raleigh NC 27695 8008 USAAccepted 22 May 1998 AbstractReclamation and reuse of water and nutrients at their source provide the opportunity touse simple less costly technologies and lessens potentials for catastrophic effects due tocentralized treatment system failures The combination of multiple treatment environmentswithin constructed wetlands can provide water quality suitable for reuse A current projectin rural Chatham County NC uses simple aesthetically pleasing treatment componentsconstructed both outdoors and indoors to reclaimdomestic sewage for toilet ushinglandscape irrigation and aesthetic water features A courtyard containing constructedwetlands and a solarium with modular soil lter components and aquatic chambers aredesigned to treat sewage from within a small business facility and to provide recreationalspace for its 60 employees The combination of vertical ow and horizontal ow constructedwetlands with ll and draw controls provides the necessary environments for nitrication–denitrication removal of organic materials and phosphorus adsorption reactions Thesystem is designed to treat and reuse 4500 l day 1 1200 gal day 1 of domestic sewage fromthe business Some of the plants used are selectively bred or genetically engineered toimize their water reclamation potential Utilization of simple treatment and reusetechnology has permitted the business owner to renovate an abandoned and deterioratingschool building into a home for two thriving andinternationally based businesses and toprotect the water quality of a nearby reservoir 1999 Published by Elsevier Science BV Allrights reservedKeywords Reuse Constructed wetlands Vertical ow Soil lter Fill and draw ReclamationCorresponding author0925-857499 - see front matter 1999 Published by Elsevier Science BV All rights reservedPII S0925-85749800052-428 CH House et al Ecological Engineering 12 1999 27–381 IntroductionAn effective nutrient management system for domestic sewage should reduceand reuse wastewater The general objective of this research project is to evaluatethe feasibility of treating and recycling 4500 l day 1 1200 gal day1 of domesticwastewater for ushing toilets Specic objectives include 1 the evaluation ofstep feed recirculation spatial aerobic and anaerobicenvironments uctuatingaerobic and anaerobic environments and zeolite absorbents for nitrogen treat-ment 2 the evaluation of brick chips as a phosphorus absorbent and nitrogenxing woody plants for phosphorus uptake and storage 3 develop a costeffectiveness analysis of on-site nitrogen and phosphorus treatment methods andon-site wastewater treatment and reuse within eastern Chatham CountyThe addition of human waste into high quality water and its disposal intoground and surface waters is not sustainable This practice makes inefcient useof water supply and simultaneously adversely impacts it Both on-site and central-ized treatment technologies can benet from the treatment and reuse of sewagenear its source On-site wastewater treatment design has evolved into a sophisti-cated technology with numerous advances but its adverse impacts onground andsurface waters as non-point sources of nitrogen phosphorus and pathogenicbacteria and virus continue Centralized treatment plants plagued by increasingdemands for expansion high cost and inconsistent funding mechanical or opera-tional failures periodically discharge partially treated wastewater into our surfacewatersMost water reuse research in the US currently focuses on irrigation of re-claimed wastewater from industrial and municipal sized systems North Carolinais just beginning to explore the potentials of water reuse Reduction of nutrientload and water volume through advanced treatment and reuse from installationswith small ows such as homes and businesses has potential to。
微生物发酵中英文对照外文翻译文献
中英文对照外文翻译文献葡萄栽培过程中产生废弃物的侧耳属菇类生物降解：一种微生物和人类食物的来源及其在动物养殖中的潜在用途在通过侧耳属菌（平菇）程序进行葡萄园剪枝和葡萄皮渣的生物转化过程中，使用固态发酵技术受到了高度评价。
我们对水果实体的生产和收获之后被酶作用物的化学变化进行了测量计算，发现生物学效率和生物转化率各自都发生了变化，分别从37.2% 上升至78.7%和16.7%上升至 38.8%。
对于菌丝生长和蘑菇产量提高最有益的基质是与葡萄园剪枝项目相混合操作。
葡萄园修剪产生的枝条与葡萄皮渣相比具有较高的酚类成分、总糖、更好的c/n比值、天然脂肪和总氨。
与之相反，在纯葡萄皮渣的实验中，菌丝生长得非常缓慢甚至是不会生长。
葡萄皮渣比例较高的混合物中水分、蛋白质、脂肪和木质素含量一般较高，然而修剪产生的葡萄枝中，中性洗涤剂纤维、半纤维素、纤维素含量较高。
侧耳菌株的生长可能依赖于基质中纤维成分的可获取情况，而且其消化过程中发生的动态变化可能随着这些纤维在真菌生长过程中的改变而发生。
通过以侧耳属菌为媒介的SSF技术对葡萄栽培残基进行回收利用的潜力巨大，可以生产出人类所需的食物以及在反刍动物饲养中还有限使用的高纤维饲料。
关键词：生物转化酶作用；侧耳属菌；回收利用；固态发酵；葡萄栽培过程的副产品引言：葡萄种植是墨西哥西北部一项重要的生产活动，在墨西哥西北部有33500公顷的土地栽培了数类不同品种的葡萄。
这么大规模的生产活动每年大约产生了大约27万吨的工农业废料，而这其中有大约93%是葡萄园修剪掉的枝条。
这些废料一般直接在田间进行焚烧处理，以防止种植物病原菌的扩散，从而引起环境和生态问题以及危害人类健康的风险。
木质素是工农业废料中所有碳含量的主要组成部分，当它在遇热降解过程中会产生多环芳香烃成分，如苯并芘、邻苯二酚、对苯二酚菲和萘。
所有这些化合物可以抑制DNA 合成，并可能诱发动物和人类的肝脏、肺、喉和子宫颈产生癌变肿瘤。
微生物英文文献Qualitative and quantitative methodologies for determination
REVIEWQualitative and quantitative methodologies for determination of airborne microorganisms at concentrated animal-feeding operationsRobert S.Dungan ÆApril B.LeytemReceived:12August 2008/Accepted:8April 2009/Published online:26April 2009ÓUS Government 2009Abstract The generation of airborne microorganisms from concentrated animal-feeding operations (CAFOs)is a concern from a human and animal health perspective.To better understand the airborne microorganisms found in these environments,a number of collection and analytical techniques have been utilized and will be discussed in this review.The most commonly used bioaerosol collection method is the liquid impingement format,which is suitable with a number of culture-based and non-culture molecular-based approaches,such as polymerase chain reaction.However,the vast majority of airborne microorganism studies conducted at CAFOs utilize culture-based analyses.Because of the limitations often associated with culture-based analyses,we focused our discussion on the applica-tion of molecular-based techniques to identify and/or quantify microorganisms,as they have promising applica-tion in bioaerosol research.The ability to rapidly charac-terize airborne microorganisms will help to ensure protection of public and environmental health.Keywords Airborne microorganisms ÁBioaerosol ÁConcentrated animal-feeding operations ÁImpaction ÁImpingement ÁNucleic acid ÁPolymerase chain reaction ÁReal-time PCRIntroductionModern animal husbandry has changed from one that was low density pasture-based to one that predominately employs confinement of animals at high stocking density.Confined or concentrated animal-feeding operations (CA-FOs)concentrate a large population of single species in one area to increase production and reduce costs.During recent decades,CAFOs have become common in many countries including The Netherlands,Denmark,France,USA,Can-ada,China,Germany,and Poland (Schulze et al.2006).A consequence of high stocking densities combined with enclosed rearing facilities,in some cases,is that the air may contain bioaerosol levels that are sufficiently high to cause adverse health effects in both animals and workers (Thorne et al.1992).Crook and Sherwood-Higham (1997)indicated that inhalation of airborne microorganisms and their constituents can be detrimental to health through infection,allergy,or toxicosis.As the environment within CAFOs can be potentially hazardous to both human and animal health at the facility as well as in surrounding areas,research is being pursued in order to quantify,characterize,and control the release of bioaerosols from CAFOs.Bioaerosols is a term commonly used to describe via-ble and non-viable airborne biological particles,such as fungal spores,bacteria,pollen,and viruses and their fragments and byproducts (Grinshpun et al.2007).Fungal spores,bacteria,and pollen are typically 1–30,0.25–8,and 17–58l m in diameter,respectively,while viruses generally have diameters \0.3l m (Jones and Harrison 2004).Matthais-Maser et al.(2000)suggested that up to 28%(by volume)of the particulate matter suspended over remote land surfaces is comprised of biological particles.Womiloju et al.(2003)concluded that fungal cells and pollen accounted for 4–11%of the total mass of airborneThe use or mention of any commercial products does not imply any endorsement of that product by either the authors or the US Department of Agriculture.R.S.Dungan (&)ÁA.B.LeytemUSDA-Agricultural Research Service,Northwest Irrigation and Soils Research Laboratory,3793North 3600East,Kimberly,ID 83341,USAe-mail:robert.dungan@123World J Microbiol Biotechnol (2009)25:1505–1518DOI 10.1007/s11274-009-0043-1particulate matter\2.5l m(PM2.5).Although microor-ganisms are ubiquitous in the ambient environment,pre-vious studies have shown higher airborne microorganism concentrations in animal houses than in industrial,resi-dential,or ambient settings(Clark et al.1983;Thorne et al.1992;Griffiths et al.1997).Bioaerosols are typically associated with particulate matter or surrounded by a thin layer of water,having an aerodynamic diameter range of0.5–100l m(Lighthart 1994;Cox1995).Bioaerosol particles1–5l m in diameter present the most concern since they are readily transported into the lung,with the greatest retention of the1–2l m particles in the alveoli(Salem and Gardner1994).The microbial component of respirable bioaerosols contributes significantly to the pulmonary diseases associated with inhalation of agricultural dusts(Merchant1987;Lacy and Crook1988).The allergenic,toxic,and inflammatory responses are caused by exposure to not only viable but also non-viable microorganisms present in bioaerosols (Robbins et al.2000;Gorny et al.2002).An estimation of occupational and residential risks from bioaerosol exposure have been addressed by Brooks et al.(2005a,b)and Tanner et al.(2008).As the generation of bioaerosols from CAFOs is a concern from a human and animal health perspective, the sampling and analysis of airborne microorganisms is of great interest.Protection of public and environmental health is dependent upon the ability to efficiently collect bioaerosol samples,then accurately identify and quantify the airborne microorganisms.In this concise review,we focus our discussion on bio-aerosol sampling and sample processing methods that are most suitable to quantitatively and qualitatively determine airborne microorganisms at CAFOs,although their appli-cation to other situations is not limited.The majorfindings of bioaerosol studies conducted at CAFOs are also dis-cussed.While this is not meant to be an exhaustive review of the literature,the reader willfind an excellent array of peer-reviewed articles on aerosol science and molecular biology and their application to studies of air quality.This review will be very useful to those interested in conducting bioaerosol research using both traditional microbiological and molecular techniques.Airborne microorganism samplingThe collection of airborne microorganisms is performed through active air sampling,which results in the efficient removal and collection of biological particles from the air in a manner that maximizes the ability to detect the organisms.Airborne microorganisms can be collected using a number of different techniques(Lundholm1982; Juozaitis et al.1994;Grinshpun et al.1996;Terzieva et al.1996;Duchaine et al.2001),but two inertial techniques,surface impaction and liquid impingement, are used in the majority of outdoor aerosol studies.Fil-tration is a non-inertial technique that separates particles from the airstream when air is passed through a porous medium,such asfibrousfilters,membranefilters,or etched membranes(Crook1995a).For airborne microor-ganisms,however,filtration poses two major disadvan-tages:(a)dehydration of cells and therefore loss of viability and/or culturability due to the large volume of air passing over the particle that is deposited on a dry medium,and(b)inconsistent and poor recovery of the deposited material from certainfilter types.Two addi-tional techniques,gravity sampling and electrostatic precipitation,have been employed for airborne microor-ganism collection but are not routinely used due to cali-bration errors and unknown performance characteristics (Pillai and Ricke2002).The most common bioaerosol sampling techniques uti-lized at cattle,poultry and swine CAFOs are presented in Table1.Direct impaction of airborne microorganisms on filters was used in*40%of the studies,while a combi-nation of liquid impingement and multistage or single stage impaction was used in*33%of the studies.Other sam-pling techniques included use of a personal slide sampler to measure fungi in a cattle shed(Adhikari et al.2004)and drag swab for determination of Salmonella in a poultry house(Endley et al.2001).The target organisms in these studies included Wallemia sebi,total bacteria and fungi, Gram-negative bacteria,heterotrophs,E.coli,enteric bac-teria,Salmonella,yeast,and molds.Impaction samplersThe surface impaction method separates particles from the airstream by utilizing the inertia of the particles to force their deposition onto a collection surface(Grinshpun et al. 2007).The collection surface is usually an agar medium for culture-based analysis or an adhesive-coated surface that can be analyzed microscopically.A commonly used impaction system is the multi-stage Andersen viable sam-pler(Thermo Scientific,Waltham,MA,USA)that con-centrates bioaerosols based on their size characteristics. Two-stage and six-stage Andersen models are available. The six-stage Andersen sampler is capable of concentrating particles in the size range of0.65–7.0l m in diameter (Grinshpun et al.2007).Air enters the sampler through an inlet nozzle and heavier particles are deposited on thefirst stage.Lighter particles not deposited on thefirst stage are carried by the airstream onto the successive stages.Single-stage impactors,which use an agar or adhesive-coated impacting surface,are available from a variety of1506World J Microbiol Biotechnol(2009)25:1505–1518 123T a b l e 1B i o a e r o s o l s t u d i e s c o n d u c t e d a t c o n c e n t r a t e d a n i m a l -f e e d i n g o p e r a t i o n s i n c l u d i n g t h e t y p e o f o p e r a t i o n ,t h e t a r g e t o r g a n i s m ,s a m p l i n g t e c h n i q u e s u t i l i z e d a n d t h e a n a l y t i c a l m e t h o d s u s e d f o r d e t e r m i n a t i o n o f m i c r o o r g a n i s m sO p e r a t i o n T a r g e t o r g a n i s m sS a m p l i n g t e c h n i q u e sA n a l y t i c a l m e t h o d s R e f e r e n c e sC o w h o u s e W a l l e m i a s e b iD i r e c t i m p a c t i o n o n fil t e r sC u l t u r e t e c h n i q u e s ,c o n v e n t i o n a l a n d r e a l t i m e P C R Z e n g e t a l .2004D u c k -f a t t e n i n g u n i tT o t a l a n d a e r o b i c G r a m -n e g a t i v e b a c t e r i a ,f u n g i ,e n d o t o x i n sL i q u i d i m p i n g e m e n t ,m u l t i -s t a g e i m p a c t i o n ,a n d d u s t s a m p l i n gC u l t u r e t e c h n i q u e s ,w h o l e b l o o d a s s a y ,E L I S A ,l i m u l u s a m e b o c y t e l y s a t e a s s a y Z u c k e r e t a l .2006C a t t l e f e e d l o t B a c t e r i a a n d f u n g iM u l t i -s t a g e i m p a c t i o nC u l t u r e t e c h n i q u e sW i l s o n e t a l .2002bC a t t l e s h e d F u n g iM u l t i -s t a g e i m p a c t i o n a n d P e r s o n a l s l i d e s a m p l e rC u l t u r e t e c h n i q u e s a n d m i c r o s c o p yA d h i k a r i e t a l .2004P i g g e r y s h e d s H e t e r o t r o p h s a n d E .c o l iL i q u i d i m p i n g e m e n t a n d m u l t i -s t a g e i m p a c t i o nC u l t u r e t e c h n i q u e sC h i n i v a s a g a m a n d B l a c k a l l 2005S w i n e b a r n sT o t a l a n d G r a m -n e g a t i v e e n t e r i c b a c t e r i a ,t o t a l f u n g iM u l t i -s t a g e i m p a c t i o n ,l i q u i d i m p i n g e m e n t ,d i r e c t i m p a c t i o n o n fil t e r sC u l t u r e t e c h n i q u e s a n d flu o r e s c e n c e m i c r o s c o p yT h o r n e e t a l .1992S w i n e b a r n sC u l t u r a l b a c t e r i a ,G r a m -n e g a t i v e b a c t e r i a ,f u n g iL i q u i d i m p i n g e m e n t ,m u l t i -s t a g e i m p a c t i o nC u l t u r e t e c h n i q u e sC h a n g e t a l .2001P o u l t r y H o u s e S a l m o n e l l aD r a g s w a b ,d i r e c t i m p a c t i o n o n fil t e r sC u l t u r e t e c h n i q u e s a n d P C RE n d l e y e t a l .2001S w i n e b a r n s H e t e r o t r o p h i c b a c t e r i aD i r e c t i m p a c t i o n o n fil t e r sC u l t u r e t e c h n i q u e sP r e d i c a l a e t a l .2001S w i n e b a r n sT o t a l a n d r e s p i r a b l e m i c r o o r g a n i s m sD i r e c t i m p a c t i o n o n fil t e r s ,m u l t i -s t a g e i m p a c t i o nC u l t u r e t e c h n i q u e sP r e d i c a l a e t a l .2002S w i n e b a r n s T o t a l b a c t e r i a a n d f u n g iS i n g l e s t a g e i m p a c t i o nC u l t u r e t e c h n i q u e sK i m e t a l .2006,2007P o u l t r y H o u s e T o t a l b a c t e r i aD i r e c t i m p a c t i o n o n fil t e r s ,l i q u i d i m p i n g e m e n tC u l t u r e t e c h n i q u e sW o o d w a r d e t a l .2004S w i n e C A F O B a c t e r i aM u l t i -s t a g e i m p a c t i o nC u l t u r e t e c h n i q u e sG r e e n e t a l .2006P o u l t r y h o u s e T o t a l a e r o b i c b a c t e r i aS i n g l e s t a g e i m p a c t i o nC u l t u r e t e c h n i q u e sV e n t e r e t a l .2004P o u l t r y ,c o w ,a n d s w i n e h o u s eA i r b o r n e m i c r o o r g a n i s m sD i r e c t i m p a c t i o n o n fil t e r sE p i flu o r e s c e n c e m i c r o s c o p yH e l d a l e t a l .1996S w i n e b a r n s T o t a l a n d c u l t u r a l b a c t e r i aL i q u i d i m p i n g e m e n t ,i m p a c t i o n o n g e l a t i n m e m b r a n e sC u l t u r e t e c h n i q u e s ,r e a l t i m e P C R ,d e n a t u r i n g g r a d i e n t g e l e l e c t r o p h o r e s i s ,p h y l o g e n e t i c a n a l y s i sN e h m e e t a l .2008D a i r y b a r n sY e a s t s ,m o l d s ,m e s o p h i l i c b a c t e r i a ,t h e r m o p h i l i c b a c t e r i aL i q u i d i m p i n g e m e n tC u l t u r e t e c h n i q u e sL a n g e e t a l .1997S w i n e C A F O V i a b l e b a c t e r i aL i q u i d i m p i n g e m e n tC u l t u r e t e c h n i q u e sR u l e e t a l .2005World J Microbiol Biotechnol (2009)25:1505–15181507123manufacturers.Adhesive-coated impacting surfaces are used for the detection of total fungal spores and pollen.In addition to the Andersen impactors,there are other impaction-based devices,such as the rotating impactor,slit sampler,and sieve-type sampler(Crook1995b).Disad-vantages associated with culture-based impactors are:(a) detection of microorganisms relies on their ability to grow after sampling and losses of culturability may occur due to sampling stress,(b)multiple particles each containing one or more organisms passing through a single impaction hole may be inaccurately counted as a single colony,and(c) culturable counts account for only0.0001–10%of the total population within environmental samples,which can severely underestimate the total population of microor-ganisms in the sample(Parkes and Taylor1985).This is also a problem when using culture-based techniques with impingement samplers.Impingement samplersImpingement samplers remove bioaerosols over a wide range of airborne particle concentrations(Grinshpun et al. 2007).The primary difference between impingement and impaction is that the bioaerosols are trapped in a liquid (e.g.,water,mineral oil,buffered solution,or dilute pep-tone solution).In theory,buffered or dilute peptone solu-tions are used to maintain the viability of the microbial cells.Most impingers are constructed from glass with a single collection chamber;though multi-stage glass liquid impinges are available(Crook1995b).The All-Glass Impinger(AGI)-30(Ace Glass,Inc,Vineland,NJ,USA)is a single chamber design that has been widely used to measure bioaerosols under various conditions(Pillai et al. 1996;Chang et al.2001;Rule et al.2005;Tanner et al. 2005;Taha et al.2006).The SKC BioSamplerÒ(SKC Inc, Eighty-Four,PA,USA)is an improved design over the AGI-30and can be operated for up to8h when mineral oil is used as the collectionfluid(Lin et al.1999).Both the SKC BioSamplerÒand AGI-30operate under an airflow rate of12.5l min-1through the use of a vacuum pump. During operation of the impinger,the microorganisms are suspended in the collectionfluid,but the high airflow velocity required for efficient particle collection also cau-ses re-aerosolization of the biological particles(Grinsphun et al.1997;Lin et al.1997)and stress that can lead to viability loss(Lin et al.1999,2000).One of the advantages of impingement samplers is the ability to utilize a variety of analytical methods.In addition to culture techniques, samples can also be analyzed via microscopy,flow cytometry,biochemical assays,immunoassays,and molecular techniques such as polymerase chain reaction (PCR)providing better detection of airborne microorganisms which may be non-culturable due to sampling stresses.High-volume samplersAnother class of bioaerosol samplers that has recently evolved due to bioterrorism and biological warfare con-cerns is high-volume samplers.Some examples of these units are the SASSÒ2300(Research International,Mon-roe,WA),BioCaptureÒ560(MesoSystems Technology, Inc,Albuquerque,NM),and the SpinconÒ(Sceptor Industries,Inc,Kansas City,MO).These samplers operate atflow rates of200–450l min-1and the bioaerosols are captured in a concentrated liquid sample.While the high-volume samplers are very costly when compared to units such as the AGI-30and SKC BioSamplerÒ,they are generally more amenable to PCR-based analyses.The ASAPÒmodel2800(Thermo Electron Corporation, Greenbush,NY,USA)sampler has an operationalflow rate of200l min-1,but collects aerosol particles by impaction on polyurethane foam.While the ASAP unit does not use a liquid impingement format like the other high-volume samples,it is currently being marketed as PCR-compatible. At this time,however,a search of the literature reveals a scarcity of peer-reviewed studies with respect to these or comparable units and their operating efficiencies(Bergman et al.2005).For a comprehensive list of commercially available bioaerosol samplers see Grinshpun et al.(2007). Sample processingOnce samples have been collected,choosing the appro-priate analytical technique is important in order to best answer the question of interest.One of the most popular methods to assess microbial populations in aerosol samples has been the use of culture-based techniques.Culture-based techniques were employed in89%of the studies reported here(Table1).As mentioned above,culture-based tech-niques can drastically underestimate the microbial popu-lations in environmental samples as less than10%of the populations may be culturable.In order to improve microorganism detection,some studies have combined the use of culture techniques with other methods such as PCR (16%),microscopy(16%),denaturing gradient gel elec-trophoresis(DGGE,5%),and immunoassays(5%).Sample preparation is important for all of these techniques,as microorganism populations in bioaerosol samples tend to be small and,therefore,concentration of samples is essential.The most commonly used sample preparation methods compatible with the molecular characterization of bioaerosols can be found below.1508World J Microbiol Biotechnol(2009)25:1505–1518 123Concentration andfilter elutionAfter bioaerosols are collected in a liquid impingement solution,it is necessary to concentrate the microorganisms before molecular methods,such as PCR,can be performed. This is necessary because the impingement solution usually contains a relatively low microbial concentration,which must be maximized to ensure sensitivity and quantification for PCR are achieved.A variety offilter materials have been tested for their compatibility with PCR(Table2)such as polytetrafluoroethylene(PTFE),polycarbonate,polyvi-nylidene difluoride,nylon,mixed cellulose ester,and nitrocellulose(Bej et al.1991a).Bej et al.(1991a)reported that PCR was not inhibited by the presence of PTFE and polyvinylidene difluoridefilters,with PTFE giving the greatest sensitivity,but was inhibited by polycarbonate, nitrocellulose,and cellulose acetatefilters.Both Nytran (Alvarez et al.1994)and nitrocellulose(Toranzos and Alvarez1992)filters have been successfully used in solid-phase PCR,where cell lysis and PCR amplification are performed on the membrane.Since DNA does bind to somefilters,it is recommended that allfilters be removed before cell lysis and PCR amplification.Filter materials that have been successfully used in PCR-based bioaerosol studies using liquid samples from glass impingers are Nytran(Alvarez et al.1994), polycarbonate(Paez-Rubio et al.2005),nylon(Alvarez et al.1995),and Teflon(Alvarez et al.1995).Aerosol samples can also be directly impinged ontofilters for subsequent PCR analysis;filters used for this purpose are tracked-etched polyester(Wilson et al.2002a),polycar-bonate(Zeng et al.2004),and polyethersulfone(Sta¨rk et al.1998).Thefilters are added to sterile distilled water (Alvarez et al.1995)or buffer solution(Wilson et al. 2002a;Zeng et al.2004;Paez-Rubio et al.2005)and then the microorganisms are eluted via agitation such as vor-texing,shaking,or sonication.Cell lysis and nucleic acid purificationAfter elution,thefilter is removed and the cells are then prepared for lysis,which can be performed either through physical,chemical,or enzymatic methods.Physical meth-ods include bead beating,sonication,microwave heating, and thermal shock(Roose-Amsaleg et al.2001),but bead beating and sonication can cause significant DNA shearing (Picard et al.1992;Miller et al.1999;Bu¨rgmann et al. 2001).Freeze-thaw lysis has been shown to release70–75% of DNA in bacterial cells after one cycle with complete lysis within six cycles(Bej et al.1991b).Chemical lysis,either alone or in combination with enzymatic methods,has been used extensively.The most widely used detergent is sodium dodecyl sulfate(SDS),whose function is to break up and dissolve cell wall lipids.Detergents are used in combination with heat treatments and chelating agents(e.g.,EDTA)and various buffers(Tris and phosphate).In addition to a detergent,many protocols include enzymatic lysis.Lyso-zyme is a commonly used lytic enzyme that breaks the b-1,4-glycosidic bonds between N-acetylglucosamine and N-acetylmuramic acid in peptidoglycan,thereby weakening the cell wall.Some proteases,like proteinase K,are also used to remove contaminating proteins(e.g.,nucleases)that might otherwise degrade nucleic acids during purification. The protease,achromopeptidase,has been used withTable2Filters utilized for preparation of bioaerosol samples for molecular methods including thefilter type,type of sample,and the methods used for sample preparation and analysisFilter Sample type Methods ReferencesPolytetrafluoroethylene, Polyvinylidenedifluoride Bacterial cells in watercollected onfiltersFreeze thaw lysis of cells fromfiltered samples,PCR DNA amplification withfilters presentBej et al.1991a,bPolycarbonate Direct impingement ofbioaerosols onfilter Filters washed in buffer to remove bacteria,DNAextraction(chemical/enzymatic),RT-PCRZeng et al.2004Polycarbonate Bioaerosols collected in liquidimpingers andfiltered Impinger solutionfiltered,DNA extraction,PCR,cloning,sequencingPaez-Rubio et al.2005Track etched polyester Direct impingement ofbioaerosols onfilter Filters washed in buffer to remove bacteria,DNAextraction(physical/chemical/enzymatic),microarray analysisWilson et al.2002aMixed cellulose nylon Bioaerosols collected in liquidimpingers andfiltered Cell lysis and DNA extraction(chemical/enzymatic)performed onfilters,solid-phasePCR used for amplificationAlvarez et al.1994Nitrocellulose Filtration of bacterial cells inwater Cell lysis and DNA extraction(chemical/enzymatic)performed onfilters,solid-phasePCR used for amplificationToranzos andAlvarez1992Polyethersulfone Direct impingement ofbioaerosols onfilter Filters were dried and dissolved in chloroform,DNA extraction(chemical),nested PCR assaySta¨rk et al.1998World J Microbiol Biotechnol(2009)25:1505–15181509123lysozyme to increase the lysis of anaerobic Gram-positive cocci(Ezaki and Suzuki1982)and extraction efficiency of nucleic acids from Frankia(Simonet et al.1984).Detailed methods on the extraction and purification of nucleic acids can be found in Sambrook and Russell(2001) and Ausubel et al.(2002).Purification of nucleic acids in bacterial lysates is generally accomplished byfirst mixing with equal volumes of phenol and chloroform.Phenol is used because it removes the proteins from the aqueous phase;chloroform is generally not necessary,but it is used to remove residual phenol from the aqueous phase.The nucleic acids are then precipitated from the aqueous phase by additions of ethanol and collected by centrifugation. The nucleic acids can then be dissolved in buffer(e.g., Tris-EDTA)and stored at-20°C.Alternatively,nucleic acids can be purified using the many commercially avail-able spin column formats that utilize silica-nucleic acid binding(Qiagen,Inc.,Fremont,CA,USA;Mo Bio Labo-ratories,Carlsbad,CA,USA;Promega,Inc.,Madison,WI, USA;MP Biomedicals,Solon,OH,USA;Invitrogen,Inc., Carlsbad,CA,USA).As a result,the spin kits require no phenol or chloroform purification or alcohol precipitation. After the silica-based membrane has been loaded with cell lysate,the DNA or RNA is cleaned by rinsing with an ethanol-containing buffer,and then eluted using a small volume of buffer or water.The characterization of airborne microorganisms Culture versus molecular-based approachesMany of the available bioaerosol sampling methods rely on culture-based techniques for the characterization and quantification of airborne microorganisms.Microorgan-isms(fungi and bacteria)that are collected on a nutrient agar surface by impaction can be cultivated directly. However,only those cells which survive,reproduce,and produce visible colonies under the specified culture con-ditions will be enumerated.The disadvantage of culture-based techniques is that not all microorganisms are cul-turable,while they still may be viable(Heidelberg et al. 1997).This could lead to an underestimation of the total microorganism concentration in the aerosol sample.With culture-based techniques,non-culturable microorganisms and their associated byproducts that may cause health effects will go undetected.While liquid samples from impingers are commonly used for culture-based analyses, they can also be analyzed by microscopy to determine total microorganism concentrations or by biochemical,immu-nological,and molecular assays to detect specific micro-organisms,both culturable and non-culturable(Cruz and Buttner2007).As an alternative to culture-based techniques,the detection of microorganisms in aerosols by PCR has become increasingly popular over the last two decades (Alvarez et al.1994;Wakefield1996;Sta¨rk et al.1998; Olsson et al.1998;Williams et al.2001;Wu et al.2003; Zeng et al.2004;Paez-Rubio et al.2005;An et al.2006) allowing for the detection of target nucleic acid sequences, thereby eliminating the need to cultivate microorganisms for their detection and identification.This is particularly useful for microorganisms that are difficult to culture,slow growing or have never been cultured before,providing increased sensitivity over traditional culture-based methods (Josephson et al.1993;Alvarez et al.1994).A limitation of the PCR assay,however,is the inability to distinguish between non-viable and viable microorganisms.While non-viable pathogenic microorganisms do not present an infectious disease risk,the presence of their DNA in a sample will often produce a positive PCR result.Therefore, one cannot truly determine if the positive result represents a potential disease threat if the viability of the microor-ganisms in the original sample was unknown.A positive detect for targeted microorganisms only means that a sample contains viable or non-viable cells or both.Non-quantitative PCRTraditional PCR involves the separation of DNA(usually a specific gene or portion of a gene)into two strands,the annealing of oligonucleotide primers to the template DNA, and then the primer-template is elongated by use of a DNA polymerase enzyme(e.g.,Taq polymerase).During PCR, each of the steps is accomplished by regulating the tem-perature of the reaction and,as a result,multiple copies of the template are produced.Guidance on the optimization of PCR can be found in several laboratory manuals(Weiss-ensteiner et al.2003;Hughes and Moody2007).By using carefully designed primers,the genetic sequence of a specific microorganism or microbial function can be tar-geted and amplified.If ribonucleic acid(RNA)is targeted, then the RNA must be converted into complementary DNA (cDNA)through a reverse transcription process,after which the resultant cDNA is PCR amplified.One advan-tage of targeting RNA(e.g.,mRNA)is that it has a very short half-life and,therefore,it is a good indicator of viable microorganisms(Bej et al.1991b).The amplified DNA is visualized most often by running the samples in an electrophoresis gel(e.g.,agarose or polyacrylamide),staining the DNA within the gel with ethidium bromide,and viewing the separated DNA under UV light.A standard molecular weight marker is run along side the samples so the size of the DNA can be determined. The amplified DNA can also be processed for genetic fingerprinting,clone library analysis,and microarray1510World J Microbiol Biotechnol(2009)25:1505–1518 123。
生物科学中英文对照外文翻译文献
中英文资料外文翻译文献译文标题：传统意大利榛子的体外繁殖用于当地遗传资源库的稳定和保存译文：关键词：欧洲榛，榛属，传统种质，体外繁殖摘要：在地中海盆地，榛子（欧洲榛）是非常重要的一种作物。
体外繁殖能够有效的稳定当地遗传资源库。
为了提高榛子微组织繁殖实验记录的精确性，各种不同的研究已经在进行。
这些研究通常以重要的品种为材料，然而，微组织繁殖实验记录应用在这些幼小品种上比起传统方法通常会产生相反的结果，这种技术在幼小品种上很少取得成功。
本实验的目的是为重要品种微组织繁殖的操作积累相关的知识和信息。
实验过程中需要设计不同成分的培养基，灭菌时间和培养时间都要进行详细的讨论。
传统意大利品种植株茎芽中的N6-异戊烯腺嘌呤的作用是改善这种状态。
生根阶段是榛属微组织繁殖应用于大型商业生产的关键步骤。
欧洲榛在欧洲特别是生物地理分布区地中海盆地代表一种重要的经济类林木。
榛子主要产于土耳其，意大利，美国和西班牙（分别是每年55,000, 110,000, 25,000, 18,000+吨），其次是法国，希腊，葡萄牙。
大约90%的产品被去皮并且以树芯的形式卖出，然而剩余的10%则作为树苗消费。
极好的营养成分和营养制品的特性也使该物种产生很高的利润。
此外，在一些特有的栽培地区，传统和文化身份严重受榛子产量的影响，文化身份常常会促进贫瘠土地的回收和利用。
即使这样，在一些地区，这种林业作物仍然不是重要的农业资源，然而，就当地足够维持的生产式系统和作为宝贵的食物的传统而言，它却是一种有趣的收入来源。
世界第二大生产商意大利说一些传统的品种主要种植在Campania ,Latium, Piedmont,在西西里岛有大量的属典型种。
近几年，一些主要品种由于质量和传统特性获得了欧洲质量印模。
此外，这些品种还被引进其他国家特定的果园中以增大他们的生长范围。
没有经过检验的物质可能会传播疾病，也可能会导致原因不明的物质的出现。
微组织繁殖法等生物技术的应用会促进健康的合乎本性的物质的产生(Nas et al.,2004)，并且提高这种林木的经济价值。
微生物英文文献及翻译—原文
Dynamic and distribution of ammonia-oxidizing bacteria communities during sludge granulation in an anaerobic e aerobic sequencing batch reactorZhang Bin a ,b ,Chen Zhe a ,b ,Qiu Zhigang a ,b ,Jin Min a ,b ,Chen Zhiqiang a ,b ,Chen Zhaoli a ,b ,Li Junwen a ,b ,Wang Xuan c ,*,Wang Jingfeng a ,b ,**aInstitute of Hygiene and Environmental Medicine,Academy of Military Medical Sciences,Tianjin 300050,PR China bTianjin Key Laboratory of Risk Assessment and Control for Environment and Food Safety,Tianjin 300050,PR China cTianjin Key Laboratory of Hollow Fiber Membrane Material and Membrane Process,Institute of Biological and Chemical Engineering,Tianjin Polytechnical University,Tianjin 300160,PR Chinaa r t i c l e i n f oArticle history:Received 30June 2011Received in revised form 10September 2011Accepted 10September 2011Available online xxx Keywords:Ammonia-oxidizing bacteria Granular sludgeCommunity development Granule sizeNitrifying bacteria distribution Phylogenetic diversitya b s t r a c tThe structure dynamic of ammonia-oxidizing bacteria (AOB)community and the distribution of AOB and nitrite-oxidizing bacteria (NOB)in granular sludge from an anaerobic e aerobic sequencing batch reactor (SBR)were investigated.A combination of process studies,molecular biotechniques and microscale techniques were employed to identify and characterize these organisms.The AOB community structure in granules was substantially different from that of the initial pattern of the inoculants sludge.Along with granules formation,the AOB diversity declined due to the selection pressure imposed by process conditions.Denaturing gradient gel electrophoresis (DGGE)and sequencing results demonstrated that most of Nitrosomonas in the inoculating sludge were remained because of their ability to rapidly adapt to the settling e washing out action.Furthermore,DGGE analysis revealed that larger granules benefit more AOB species surviving in the reactor.In the SBR were various size granules coexisted,granule diameter affected the distribution range of AOB and NOB.Small and medium granules (d <0.6mm)cannot restrict oxygen mass transfer in all spaces of the rger granules (d >0.9mm)can result in smaller aerobic volume fraction and inhibition of NOB growth.All these observations provide support to future studies on the mechanisms responsible for the AOB in granules systems.ª2011Elsevier Ltd.All rights reserved.1.IntroductionAt sufficiently high levels,ammonia in aquatic environments can be toxic to aquatic life and can contribute to eutrophica-tion.Accordingly,biodegradation and elimination of ammonia in wastewater are the primary functions of thewastewater treatment process.Nitrification,the conversion of ammonia to nitrate via nitrite,is an important way to remove ammonia nitrogen.It is a two-step process catalyzed by ammonia-oxidizing and nitrite-oxidizing bacteria (AOB and NOB).Aerobic ammonia-oxidation is often the first,rate-limiting step of nitrification;however,it is essential for the*Corresponding author .**Corresponding author.Institute of Hygiene and Environmental Medicine,Academy of Military Medical Sciences,Tianjin 300050,PR China.Tel.:+862284655498;fax:+862223328809.E-mail addresses:wangxuan0116@ (W.Xuan),jingfengwang@ (W.Jingfeng).Available online atjournal homepage:/locate/watresw a t e r r e s e a r c h x x x (2011)1e 100043-1354/$e see front matter ª2011Elsevier Ltd.All rights reserved.doi:10.1016/j.watres.2011.09.026removal of ammonia from the wastewater(Prosser and Nicol, 2008).Comparative analyses of16S rRNA sequences have revealed that most AOB in activated sludge are phylogeneti-cally closely related to the clade of b-Proteobacteria (Kowalchuk and Stephen,2001).However,a number of studies have suggested that there are physiological and ecological differences between different AOB genera and lineages,and that environmental factors such as process parameter,dis-solved oxygen,salinity,pH,and concentrations of free ammonia can impact certain species of AOB(Erguder et al., 2008;Kim et al.,2006;Koops and Pommerening-Ro¨ser,2001; Kowalchuk and Stephen,2001;Shi et al.,2010).Therefore, the physiological activity and abundance of AOB in waste-water processing is critical in the design and operation of waste treatment systems.For this reason,a better under-standing of the ecology and microbiology of AOB in waste-water treatment systems is necessary to enhance treatment performance.Recently,several developed techniques have served as valuable tools for the characterization of microbial diversity in biological wastewater treatment systems(Li et al., 2008;Yin and Xu,2009).Currently,the application of molec-ular biotechniques can provide clarification of the ammonia-oxidizing community in detail(Haseborg et al.,2010;Tawan et al.,2005;Vlaeminck et al.,2010).In recent years,the aerobic granular sludge process has become an attractive alternative to conventional processes for wastewater treatment mainly due to its cell immobilization strategy(de Bruin et al.,2004;Liu et al.,2009;Schwarzenbeck et al.,2005;Schwarzenbeck et al.,2004a,b;Xavier et al.,2007). Granules have a more tightly compact structure(Li et al.,2008; Liu and Tay,2008;Wang et al.,2004)and rapid settling velocity (Kong et al.,2009;Lemaire et al.,2008).Therefore,granular sludge systems have a higher mixed liquid suspended sludge (MLSS)concentration and longer solid retention times(SRT) than conventional activated sludge systems.Longer SRT can provide enough time for the growth of organisms that require a long generation time(e.g.,AOB).Some studies have indicated that nitrifying granules can be cultivated with ammonia-rich inorganic wastewater and the diameter of granules was small (Shi et al.,2010;Tsuneda et al.,2003).Other researchers reported that larger granules have been developed with the synthetic organic wastewater in sequencing batch reactors(SBRs)(Li et al., 2008;Liu and Tay,2008).The diverse populations of microor-ganisms that coexist in granules remove the chemical oxygen demand(COD),nitrogen and phosphate(de Kreuk et al.,2005). However,for larger granules with a particle diameter greater than0.6mm,an outer aerobic shell and an inner anaerobic zone coexist because of restricted oxygen diffusion to the granule core.These properties of granular sludge suggest that the inner environment of granules is unfavorable to AOB growth.Some research has shown that particle size and density induced the different distribution and dominance of AOB,NOB and anam-mox(Winkler et al.,2011b).Although a number of studies have been conducted to assess the ecology and microbiology of AOB in wastewater treatment systems,the information on the dynamics,distribution,and quantification of AOB communities during sludge granulation is still limited up to now.To address these concerns,the main objective of the present work was to investigate the population dynamics of AOB communities during the development of seedingflocs into granules,and the distribution of AOB and NOB in different size granules from an anaerobic e aerobic SBR.A combination of process studies,molecular biotechniques and microscale techniques were employed to identify and char-acterize these organisms.Based on these approaches,we demonstrate the differences in both AOB community evolu-tion and composition of theflocs and granules co-existing in the SBR and further elucidate the relationship between distribution of nitrifying bacteria and granule size.It is ex-pected that the work would be useful to better understand the mechanisms responsible for the AOB in granules and apply them for optimal control and management strategies of granulation systems.2.Material and methods2.1.Reactor set-up and operationThe granules were cultivated in a lab-scale SBR with an effective volume of4L.The effective diameter and height of the reactor was10cm and51cm,respectively.The hydraulic retention time was set at8h.Activated sludge from a full-scale sewage treat-ment plant(Jizhuangzi Sewage Treatment Works,Tianjin, China)was used as the seed sludge for the reactor at an initial sludge concentration of3876mg LÀ1in MLSS.The reactor was operated on6-h cycles,consisting of2-min influent feeding,90-min anaerobic phase(mixing),240-min aeration phase and5-min effluent discharge periods.The sludge settling time was reduced gradually from10to5min after80SBR cycles in20days, and only particles with a settling velocity higher than4.5m hÀ1 were retained in the reactor.The composition of the influent media were NaAc(450mg LÀ1),NH4Cl(100mg LÀ1),(NH4)2SO4 (10mg LÀ1),KH2PO4(20mg LÀ1),MgSO4$7H2O(50mg LÀ1),KCl (20mg LÀ1),CaCl2(20mg LÀ1),FeSO4$7H2O(1mg LÀ1),pH7.0e7.5, and0.1mL LÀ1trace element solution(Li et al.,2007).Analytical methods-The total organic carbon(TOC),NHþ4e N, NOÀ2e N,NOÀ3e N,total nitrogen(TN),total phosphate(TP) concentration,mixed liquid suspended solids(MLSS) concentration,and sludge volume index at10min(SVI10)were measured regularly according to the standard methods (APHA-AWWA-WEF,2005).Sludge size distribution was determined by the sieving method(Laguna et al.,1999).Screening was performed with four stainless steel sieves of5cm diameter having respective mesh openings of0.9,0.6,0.45,and0.2mm.A100mL volume of sludge from the reactor was sampled with a calibrated cylinder and then deposited on the0.9mm mesh sieve.The sample was subsequently washed with distilled water and particles less than0.9mm in diameter passed through this sieve to the sieves with smaller openings.The washing procedure was repeated several times to separate the gran-ules.The granules collected on the different screens were recovered by backwashing with distilled water.Each fraction was collected in a different beaker andfiltered on quantitative filter paper to determine the total suspended solid(TSS).Once the amount of total suspended solid(TSS)retained on each sieve was acquired,it was reasonable to determine for each class of size(<0.2,[0.2e0.45],[0.45e0.6],[0.6e0.9],>0.9mm) the percentage of the total weight that they represent.w a t e r r e s e a r c h x x x(2011)1e10 22.2.DNA extraction and nested PCR e DGGEThe sludge from approximately8mg of MLSS was transferred into a1.5-mL Eppendorf tube and then centrifuged at14,000g for10min.The supernatant was removed,and the pellet was added to1mL of sodium phosphate buffer solution and aseptically mixed with a sterilized pestle in order to detach granules.Genomic DNA was extracted from the pellets using E.Z.N.A.äSoil DNA kit(D5625-01,Omega Bio-tek Inc.,USA).To amplify ammonia-oxidizer specific16S rRNA for dena-turing gradient gel electrophoresis(DGGE),a nested PCR approach was performed as described previously(Zhang et al., 2010).30m l of nested PCR amplicons(with5m l6Âloading buffer)were loaded and separated by DGGE on polyacrylamide gels(8%,37.5:1acrylamide e bisacrylamide)with a linear gradient of35%e55%denaturant(100%denaturant¼7M urea plus40%formamide).The gel was run for6.5h at140V in 1ÂTAE buffer(40mM Tris-acetate,20mM sodium acetate, 1mM Na2EDTA,pH7.4)maintained at60 C(DCodeäUniversal Mutation Detection System,Bio-Rad,Hercules,CA, USA).After electrophoresis,silver-staining and development of the gels were performed as described by Sanguinetti et al. (1994).These were followed by air-drying and scanning with a gel imaging analysis system(Image Quant350,GE Inc.,USA). The gel images were analyzed with the software Quantity One,version4.31(Bio-rad).Dice index(Cs)of pair wise community similarity was calculated to evaluate the similarity of the AOB community among DGGE lanes(LaPara et al.,2002).This index ranges from0%(no common band)to100%(identical band patterns) with the assistance of Quantity One.The Shannon diversity index(H)was used to measure the microbial diversity that takes into account the richness and proportion of each species in a population.H was calculatedusing the following equation:H¼ÀPn iNlogn iN,where n i/Nis the proportion of community made up by species i(bright-ness of the band i/total brightness of all bands in the lane).Dendrograms relating band pattern similarities were automatically calculated without band weighting(consider-ation of band density)by the unweighted pair group method with arithmetic mean(UPGMA)algorithms in the Quantity One software.Prominent DGGE bands were excised and dissolved in30m L Milli-Q water overnight,at4 C.DNA was recovered from the gel by freeze e thawing thrice.Cloning and sequencing of the target DNA fragments were conducted following the estab-lished method(Zhang et al.,2010).2.3.Distribution of nitrifying bacteriaThree classes of size([0.2e0.45],[0.45e0.6],>0.9mm)were chosen on day180for FISH analysis in order to investigate the spatial distribution characteristics of AOB and NOB in granules.2mg sludge samples werefixed in4%para-formaldehyde solution for16e24h at4 C and then washed twice with sodium phosphate buffer;the samples were dehydrated in50%,80%and100%ethanol for10min each. Ethanol in the granules was then completely replaced by xylene by serial immersion in ethanol-xylene solutions of3:1, 1:1,and1:3by volume andfinally in100%xylene,for10min periods at room temperature.Subsequently,the granules were embedded in paraffin(m.p.56e58 C)by serial immer-sion in1:1xylene-paraffin for30min at60 C,followed by 100%paraffin.After solidification in paraffin,8-m m-thick sections were prepared and placed on gelatin-coated micro-scopic slides.Paraffin was removed by immersing the slide in xylene and ethanol for30min each,followed by air-drying of the slides.The three oligonucleotide probes were used for hybridiza-tion(Downing and Nerenberg,2008):FITC-labeled Nso190, which targets the majority of AOB;TRITC-labeled NIT3,which targets Nitrobacter sp.;TRITC-labeled NSR1156,which targets Nitrospira sp.All probe sequences,their hybridization condi-tions,and washing conditions are given in Table1.Oligonu-cleotides were synthesized andfluorescently labeled with fluorochomes by Takara,Inc.(Dalian,China).Hybridizations were performed at46 C for2h with a hybridization buffer(0.9M NaCl,formamide at the percentage shown in Table1,20mM Tris/HCl,pH8.0,0.01% SDS)containing each labeled probe(5ng m LÀ1).After hybrid-ization,unbound oligonucleotides were removed by a strin-gent washing step at48 C for15min in washing buffer containing the same components as the hybridization buffer except for the probes.For detection of all DNA,4,6-diamidino-2-phenylindole (DAPI)was diluted with methanol to afinal concentration of1ng m LÀ1.Cover the slides with DAPI e methanol and incubate for15min at37 C.The slides were subsequently washed once with methanol,rinsed briefly with ddH2O and immediately air-dried.Vectashield(Vector Laboratories)was used to prevent photo bleaching.The hybridization images were captured using a confocal laser scanning microscope (CLSM,Zeiss710).A total of10images were captured for each probe at each class of size.The representative images were selected andfinal image evaluation was done in Adobe PhotoShop.w a t e r r e s e a r c h x x x(2011)1e1033.Results3.1.SBR performance and granule characteristicsDuring the startup period,the reactor removed TOC and NH 4þ-N efficiently.98%of NH 4þ-N and 100%of TOC were removed from the influent by day 3and day 5respectively (Figs.S2,S3,Supporting information ).Removal of TN and TP were lower during this period (Figs.S3,S4,Supporting information ),though the removal of TP gradually improved to 100%removal by day 33(Fig.S4,Supporting information ).To determine the sludge volume index of granular sludge,a settling time of 10min was chosen instead of 30min,because granular sludge has a similar SVI after 60min and after 5min of settling (Schwarzenbeck et al.,2004b ).The SVI 10of the inoculating sludge was 108.2mL g À1.The changing patterns of MLSS and SVI 10in the continuous operation of the SBR are illustrated in Fig.1.The sludge settleability increased markedly during the set-up period.Fig.2reflects the slow andgradual process of sludge granulation,i.e.,from flocculentsludge to granules.3.2.DGGE analysis:AOB communities structure changes during sludge granulationThe results of nested PCR were shown in Fig.S1.The well-resolved DGGE bands were obtained at the representative points throughout the GSBR operation and the patterns revealed that the structure of the AOB communities was dynamic during sludge granulation and stabilization (Fig.3).The community structure at the end of experiment was different from that of the initial pattern of the seed sludge.The AOB communities on day 1showed 40%similarity only to that at the end of the GSBR operation (Table S1,Supporting information ),indicating the considerable difference of AOB communities structures between inoculated sludge and granular sludge.Biodiversity based on the DGGE patterns was analyzed by calculating the Shannon diversity index H as204060801001201401254159738494104115125135147160172188Time (d)S V I 10 (m L .g -1)10002000300040005000600070008000900010000M L S S (m g .L -1)Fig.1e Change in biomass content and SVI 10during whole operation.SVI,sludge volume index;MLSS,mixed liquid suspendedsolids.Fig.2e Variation in granule size distribution in the sludge during operation.d,particle diameter;TSS,total suspended solids.w a t e r r e s e a r c h x x x (2011)1e 104shown in Fig.S5.In the phase of sludge inoculation (before day 38),H decreased remarkably (from 0.94to 0.75)due to the absence of some species in the reactor.Though several dominant species (bands2,7,10,11)in the inoculating sludge were preserved,many bands disappeared or weakened (bands 3,4,6,8,13,14,15).After day 45,the diversity index tended to be stable and showed small fluctuation (from 0.72to 0.82).Banding pattern similarity was analyzed by applying UPGMA (Fig.4)algorithms.The UPGMA analysis showed three groups with intragroup similarity at approximately 67%e 78%and intergroup similarity at 44e 62%.Generally,the clustering followed the time course;and the algorithms showed a closer clustering of groups II and III.In the analysis,group I was associated with sludge inoculation and washout,group IIwithFig.3e DGGE profile of the AOB communities in the SBR during the sludge granulation process (lane labels along the top show the sampling time (days)from startup of the bioreactor).The major bands were labeled with the numbers (bands 1e15).Fig.4e UPGMA analysis dendrograms of AOB community DGGE banding patterns,showing schematics of banding patterns.Roman numerals indicate major clusters.w a t e r r e s e a r c h x x x (2011)1e 105startup sludge granulation and decreasing SVI 10,and group III with a stable system and excellent biomass settleability.In Fig.3,the locations of the predominant bands were excised from the gel.DNA in these bands were reamplified,cloned and sequenced.The comparative analysis of these partial 16S rRNA sequences (Table 2and Fig.S6)revealed the phylogenetic affiliation of 13sequences retrieved.The majority of the bacteria in seed sludge grouped with members of Nitrosomonas and Nitrosospira .Along with sludge granula-tion,most of Nitrosomonas (Bands 2,5,7,9,10,11)were remained or eventually became dominant in GSBR;however,all of Nitrosospira (Bands 6,13,15)were gradually eliminated from the reactor.3.3.Distribution of AOB and NOB in different sized granulesFISH was performed on the granule sections mainly to deter-mine the location of AOB and NOB within the different size classes of granules,and the images were not further analyzed for quantification of cell counts.As shown in Fig.6,in small granules (0.2mm <d <0.45mm),AOB located mainly in the outer part of granular space,whereas NOB were detected only in the core of granules.In medium granules (0.45mm <d <0.6mm),AOB distributed evenly throughout the whole granular space,whereas NOB still existed in the inner part.In the larger granules (d >0.9mm),AOB and NOB were mostly located in the surface area of the granules,and moreover,NOB became rare.4.Discussion4.1.Relationship between granule formation and reactor performanceAfter day 32,the SVI 10stabilized at 20e 35mL g À1,which is very low compared to the values measured for activated sludge (100e 150mL g À1).However,the size distribution of the granules measured on day 32(Fig.2)indicated that only 22%of the biomass was made of granular sludge with diameter largerthan 0.2mm.These results suggest that sludge settleability increased prior to granule formation and was not affected by different particle sizes in the sludge during the GSBR operation.It was observed,however,that the diameter of the granules fluctuated over longer durations.The large granules tended to destabilize due to endogenous respiration,and broke into smaller granules that could seed the formation of large granules again.Pochana and Keller reported that physically broken sludge flocs contribute to lower denitrification rates,due to their reduced anoxic zone (Pochana and Keller,1999).Therefore,TN removal efficiency raises fluctuantly throughout the experiment.Some previous research had demonstrated that bigger,more dense granules favored the enrichment of PAO (Winkler et al.,2011a ).Hence,after day 77,removal efficiency of TP was higher and relatively stable because the granules mass fraction was over 90%and more larger granules formed.4.2.Relationship between AOB communities dynamic and sludge granulationFor granule formation,a short settling time was set,and only particles with a settling velocity higher than 4.5m h À1were retained in the reactor.Moreover,as shown in Fig.1,the variation in SVI 10was greater before day 41(from 108.2mL g À1e 34.1mL g À1).During this phase,large amounts of biomass could not survive in the reactor.A clear shift in pop-ulations was evident,with 58%similarity between days 8and 18(Table S1).In the SBR system fed with acetate-based synthetic wastewater,heterotrophic bacteria can produce much larger amounts of extracellular polysaccharides than autotrophic bacteria (Tsuneda et al.,2003).Some researchers found that microorganisms in high shear environments adhered by extracellular polymeric substances (EPS)to resist the damage of suspended cells by environmental forces (Trinet et al.,1991).Additionally,it had been proved that the dominant heterotrophic species in the inoculating sludge were preserved throughout the process in our previous research (Zhang et al.,2011).It is well known that AOB are chemoau-totrophic and slow-growing;accordingly,numerous AOBw a t e r r e s e a r c h x x x (2011)1e 106populations that cannot become big and dense enough to settle fast were washed out from the system.As a result,the variation in AOB was remarkable in the period of sludge inoculation,and the diversity index of population decreased rapidly.After day 45,AOB communities’structure became stable due to the improvement of sludge settleability and the retention of more biomass.These results suggest that the short settling time (selection pressure)apparently stressed the biomass,leading to a violent dynamic of AOB communities.Further,these results suggest that certain populations may have been responsible for the operational success of the GSBR and were able to persist despite the large fluctuations in pop-ulation similarity.This bacterial population instability,coupled with a generally acceptable bioreactor performance,is congruent with the results obtained from a membrane biore-actor (MBR)for graywater treatment (Stamper et al.,2003).Nitrosomonas e like and Nitrosospira e like populations are the dominant AOB populations in wastewater treatment systems (Kowalchuk and Stephen,2001).A few previous studies revealed that the predominant populations in AOB communities are different in various wastewater treatment processes (Tawan et al.,2005;Thomas et al.,2010).Some researchers found that the community was dominated by AOB from the genus Nitrosospira in MBRs (Zhang et al.,2010),whereas Nitrosomonas sp.is the predominant population in biofilter sludge (Yin and Xu,2009).In the currentstudy,Fig.5e DGGE profile of the AOB communities in different size of granules (lane labels along the top show the range of particle diameter (d,mm)).Values along the bottom indicate the Shannon diversity index (H ).Bands labeled with the numbers were consistent with the bands in Fig.3.w a t e r r e s e a r c h x x x (2011)1e 107sequence analysis revealed that selection pressure evidently effect on the survival of Nitrosospira in granular sludge.Almost all of Nitrosospira were washed out initially and had no chance to evolve with the environmental changes.However,some members of Nitrosomonas sp.have been shown to produce more amounts of EPS than Nitrosospira ,especially under limited ammonia conditions (Stehr et al.,1995);and this feature has also been observed for other members of the same lineage.Accordingly,these EPS are helpful to communicate cells with each other and granulate sludge (Adav et al.,2008).Therefore,most of Nitrosomonas could adapt to this challenge (to become big and dense enough to settle fast)and were retained in the reactor.At the end of reactor operation (day 180),granules with different particle size were sieved.The effects of variation in granules size on the composition of the AOBcommunitiesFig.6e Micrographs of FISH performed on three size classes of granule sections.DAPI stain micrographs (A,D,G);AOB appear as green fluorescence (B,E,H),and NOB appear as red fluorescence (C,F,I).Bar [100m m in (A)e (C)and (G)e (I).d,particle diameter.(For interpretation of the references to colour in this figure legend,the reader is referred to the web version of this article.)w a t e r r e s e a r c h x x x (2011)1e 108were investigated.As shown in Fig.5,AOB communities structures in different size of granules were varied.Although several predominant bands(bands2,5,11)were present in all samples,only bands3and6appeared in the granules with diameters larger than0.6mm.Additionally,bands7and10 were intense in the granules larger than0.45mm.According to Table2,it can be clearly indicated that Nitrosospira could be retained merely in the granules larger than0.6mm.Therefore, Nitrosospira was not present at a high level in Fig.3due to the lower proportion of larger granules(d>0.6mm)in TSS along with reactor operation.DGGE analysis also revealed that larger granules had a greater microbial diversity than smaller ones. This result also demonstrates that more organisms can survive in larger granules as a result of more space,which can provide the suitable environment for the growth of microbes(Fig.6).4.3.Effect of variance in particle size on the distribution of AOB and NOB in granulesAlthough an influence of granule size has been observed in experiments and simulations for simultaneous N-and P-removal(de Kreuk et al.,2007),the effect of granule size on the distribution of different biomass species need be revealed further with the assistance of visible experimental results, especially in the same granular sludge reactors.Related studies on the diversity of bacterial communities in granular sludge often focus on the distribution of important functional bacteria populations in single-size granules(Matsumoto et al., 2010).In the present study,different size granules were sieved,and the distribution patterns of AOB and NOB were explored.In the nitrification processes considered,AOB and NOB compete for space and oxygen in the granules(Volcke et al.,2010).Since ammonium oxidizers have a higheroxygen affinity(K AOBO2<K NOBO2)and accumulate more rapidly inthe reactor than nitrite oxidizers(Volcke et al.,2010),NOB are located just below the layer of AOB,where still some oxygen is present and allows ready access to the nitrite produced.In smaller granules,the location boundaries of the both biomass species were distinct due to the limited existence space provided by granules for both microorganism’s growth.AOB exist outside of the granules where oxygen and ammonia are present.Medium granules can provide broader space for microbe multiplying;accordingly,AOB spread out in the whole granules.This result also confirms that oxygen could penetrate deep into the granule’s core without restriction when particle diameter is less than0.6mm.Some mathematic model also supposed that NOBs are favored to grow in smaller granules because of the higher fractional aerobic volume (Volcke et al.,2010).As shown in the results of the batch experiments(Zhang et al.,2011),nitrite accumulation temporarily occurred,accompanied by the more large gran-ules(d>0.9mm)forming.This phenomenon can be attrib-uted to the increased ammonium surface load associated with larger granules and smaller aerobic volume fraction,resulting in outcompetes of NOB.It also suggests that the core areas of large granules(d>0.9mm)could provide anoxic environment for the growth of anaerobic denitrificans(such as Tb.deni-trificans or Tb.thioparus in Fig.S7,Supporting information).As shown in Fig.2and Fig.S3,the removal efficiency of total nitrogen increased with formation of larger granules.5.ConclusionsThe variation in AOB communities’structure was remarkable during sludge inoculation,and the diversity index of pop-ulation decreased rapidly.Most of Nitrosomonas in the inocu-lating sludge were retained because of their capability to rapidly adapt to the settling e washing out action.DGGE anal-ysis also revealed that larger granules had greater AOB diversity than that of smaller ones.Oxygen penetration was not restricted in the granules of less than0.6mm particle diameter.However,the larger granules(d>0.9mm)can result in the smaller aerobic volume fraction and inhibition of NOB growth.Henceforth,further studies on controlling and opti-mizing distribution of granule size could be beneficial to the nitrogen removal and expansive application of granular sludge technology.AcknowledgmentsThis work was supported by grants from the National Natural Science Foundation of China(No.51108456,50908227)and the National High Technology Research and Development Program of China(No.2009AA06Z312).Appendix.Supplementary dataSupplementary data associated with this article can be found in online version at doi:10.1016/j.watres.2011.09.026.r e f e r e n c e sAdav,S.S.,Lee, D.J.,Show,K.Y.,2008.Aerobic granular sludge:recent advances.Biotechnology Advances26,411e423.APHA-AWWA-WEF,2005.Standard Methods for the Examination of Water and Wastewater,first ed.American Public Health Association/American Water Works Association/WaterEnvironment Federation,Washington,DC.de Bruin,L.M.,de Kreuk,M.,van der Roest,H.F.,Uijterlinde,C., van Loosdrecht,M.C.M.,2004.Aerobic granular sludgetechnology:an alternative to activated sludge?Water Science and Technology49,1e7.de Kreuk,M.,Heijnen,J.J.,van Loosdrecht,M.C.M.,2005.Simultaneous COD,nitrogen,and phosphate removal byaerobic granular sludge.Biotechnology and Bioengineering90, 761e769.de Kreuk,M.,Picioreanu,C.,Hosseini,M.,Xavier,J.B.,van Loosdrecht,M.C.M.,2007.Kinetic model of a granular sludge SBR:influences on nutrient removal.Biotechnology andBioengineering97,801e815.Downing,L.S.,Nerenberg,R.,2008.Total nitrogen removal ina hybrid,membrane-aerated activated sludge process.WaterResearch42,3697e3708.Erguder,T.H.,Boon,N.,Vlaeminck,S.E.,Verstraete,W.,2008.Partial nitrification achieved by pulse sulfide doses ina sequential batch reactor.Environmental Science andTechnology42,8715e8720.w a t e r r e s e a r c h x x x(2011)1e109。
微生物外文翻译之三
Microbial degradation of PAHs and other hydrophobic substrates is believed to be limited by the amounts dissolved in the water phase (Ogram et al., 1985; Rijnaarts et al., 1990; Volkering et al., 1992; Volkering et al., 1993; Harms and Bosma, 1997; Bosma et al., 1997), with sorbed, crystalline, and non-aqueous phase liquid (NAPL)-dissolved PAHs being unavailable to PAH-degrading organisms. Bioavailability is considered a dynamic process, determined by the rate of substrate mass-transfer to microbial cells relative to their intrinsic catabolic activity (Bosma et al., 1997; Harms and Bosma, 1997). It has been described by a bioavailability number, Bn, (Koch, 1990; Bosma et al., 1997), which is a measure of a microorganism’s substrate degradation efficiency in a given environment. Bn is defined as the capacity of an organism’s or a population’s environment to provide a chemical, divided by the capacity of the organism or population to transform that chemical. At high mass transfer rates, the overall biodegradation rate is controlled by the metabolic activity of the bacteria (Bn > 1), i.e. by both the specific activity of the cells and the population density. At Bn ¼ 1, the biodegradation rate is equally controlled by the physical transport and the microbial activity. When the transport of the substrate decreases or the bacterial population grows, the mass transfer becomes the factor that limits the biodegradation (Bn ! 1).
微生物外文翻译之七
Research papersDecolorization of azo dyes by Phanerochaete chrysosporium andPleurotus sajorcajuEliana Pereira Chagas,Lucia Regina Durrant*Faculdade de Engenharia de Alimentos,Universidade Estadual de Campinas (Unicamp),Caixa Postal 6121,CEP 13081–970Campinas-SP,BrazilReceived 18October 1999;received in revised form 12December 2000;accepted 24May 2001AbstractMany synthetic dyes present in industrial wastewaters are resistant to degradation by conventional treatments.Decolorization of four synthetic azo dyes was examined in two white rot fungal cultures.In solidified culture medium,Phanerochaete chrysosporium partially decolorized all the dyes tested,while Pleurotus sajorcaju totally decolorized amaranth,new coccine,and orange G,but not tartrazine.In liquid culture medium,P.chrysosporium totally decolorized amaranth,new coccine and orange G,and 60%tartrazine.Pleurotus sajorcaju totally decolorized amaranth and new coccine,50%orange G and a maximum of 20%tartrazine.Neither fungus showed lignin peroxidase or veratryl alcohol oxidase activities,suggesting that these enzymes may not be involved in the decolorization.Manganese-peroxidase and -glucosidase may be involved in the decolorization of the dyes by P.chrysosporium,whereas in P.sajorcaju a laccase active toward o-dianisidine,and glucose-1-oxidase might participate in the process.©2001Elsevier Science Inc.All rights reserved.Keywords:White-rot fungi;Azo dyes;Decolorization;Food1.IntroductionThe white-rot fungi use a highly non-specific,free-radi-cal-mediated process,which requires enzymes to degrade lignin and structurally related compounds.These enzymes are able to catalyze a variety of oxidation and reductions,as well as to produce highly reactive oxygen species.The nonspecific mechanisms used by these fungi allow them to degrade a wide array of pollutant substances resembling lignin or its derivatives.Synthetic dyes have been increasingly used in the textile,paper,cosmetics,pharmaceutical and food industries be-cause of their ease of use,cost effectiveness in synthesis,stability and variety of color compared with natural dyes [1].Azo dyes,the largest class of synthetic dyes used in the food industries,are characterized by the presence of one or more azo bonds (-N ϭN-)in association with one or more aromatic systems,which may also carry sulfonic acid groups.Many studies indicate that these dyes are toxic orcarcinogenic.If these colorants come into contact with cer-tain drugs (e.g.aspirin,benzoic acid)within the human body they can induce allergic and asthmatic reactions in sensitive people [2].An additional difficulty is that,when present,these dyes are not normally removed by conven-tional wastewater treatment systems.Therefore,the em-ployment of these dyes must be controlled and the effluents must be treated before being released into the aquatic and terrestrial environment [3].The ability of wood-rotting fungi to degrade a wide range of synthetic chemicals,including dyes,has been re-ported.They can mineralize xenobiotic materials to CO 2and H 2O through their highly oxidative and non-specific ligninolytic system [4,5].Most azo-dye-degrading microorganisms cleave the azo bond(s)of the respective azo dye and produce decolorized products [6].Bacterial degradation of azo dyes is carried out mostly anaerobically with only a few strains being capable of degradation under aerobic conditions.In both cases col-orless,and possibly toxic,aromatic amines are formed [6,7].The white-rot fungi have been reported to efficiently de-grade azo dyes without the formation of aromatic amines [5,8].In this study,we show the ability of two white-rot fungi*Corresponding author.Tel.:ϩ55-1978-87276;fax:ϩ55-1978-81513.E-mail address:durrant@fea.unicamp.br (L.R.Durrant)/locate/enzmictecEnzyme and Microbial Technology 29(2001)473–4770141-0229/01/$–see front matter ©2001Elsevier Science Inc.All rights reserved.PII:S0141-0229(01)00405-7to decolorize some azo dyes used in the food industries.Theenzyme system produced during growth was also deter-mined.2.Materials and methods2.1.ChemicalsOrange G(sunset yellow FCF),new coccine(ponceau4R),p-nitrophenyl--D-glucopyranoside,cellobiose and sy-ringaldazine were obtained from Sigma(Switzerland),o-dianisidine was from Sigma(USA).Tartrazine was fromInlab(Brazil)and amaranth from Aldrich(Switzerland).Thiamin and agar were obtained from Merck(Germany).3-methoxy-5-tert-butyl-benzoquinone was from Fluka(Switzerland).ABTS(2,2Ј-azino-bis-ethylbenthiazoline)was from Boering-Manhering(Germany).2.2.Microorganisms and dyesThe fungal strains were Phanerochaete chrysosporiumATCC24725and Pleurotus sajorcaju020obtained fromthe culture collection of the Systematic and Microbial Phys-iology Laboratory of the Food Engineering Faculty of Uni-camp,Campinas-SP.Dyes used were amaranth(red),new coccine(red),or-ange G(orange),50.0mg/liter(final concentration),andtartrazine(yellow),10.0mg/liter(final concentration).2.3.InoculumThe fungi were inoculated on malt agar(30.0g/liter maltextract,5.0g/liter peptone and15.0g/liter agar)and incu-bated(P.chrysosporium—37°C,P.sajorcaju—30°C)untilextensive mycelial growth occurred.They were then di-vided into pieces of1cm2and for each10.0ml liquidculture media,one square was added to theflasks.Forgrowth on solid media,one mycelial piece was placed at thecenter of the Petri dish containing medium.The liquid media contained3.8mM(NH4)2SO4,5.8mMKH2PO4,1.7mM K2HPO4,1.2mM MgSO4.7H2O,14.0M ZnSO4.6H2O,30.0M MnSO4,370.0M CaCl2.2H2O,0.02%(w/v)yeast extract,1.0ml of a1.0%(w/v)thiamin solution and dye as the carbon source.Forsolid colored media1.5%(w/v)agar was added.Followinginoculation theflasks(50.0ml medium/125ml Erlenmeyer)were incubated at100rpm for8days,when the supernatantswere collected and the decolorization was determined asdescribed below.Following the determination of the decolorization of thedyes,amaranth and tartrazine,which are very distinct struc-turally and were respectively the highest and the least de-colorized dyes,were used for growth of both fungi in liquidmedia as described above.Supernatant samples were col-lected at2,4,5,6,7and8days of growth.The pH was measured and the samples were then used for the determi-nation of enzyme activities and of decolorization.The fun-gal biomasses were washed,dried at80°C for24h and weighed.Controls consisting of either uninoculatedflasks or inoc-ulated medium with no dye addition were also prepared.2.4.Enzyme activitiesThe enzymatic activities of lignin peroxidase(LiP)[9], laccase(o-dianisidine(D)and syringaldazine(S))[10], manganese-peroxidase(MnP)[11],glucose-1-oxidase (GOD)[12],-glucosidase[13]and cellobiose-quinone-oxidoredutase(CBQ)[14]were determined.Veratryl alco-hol oxidase(VAO)was determined as LiP,but H2O2was replaced by H2O.One unit LiP,VAO,laccase,MnP,GOD and CBQ was defined as1.0mol of substrate oxidized per minute per liter.One unit-glucosidase was defined as1.0 mmol of substrate transformed per minute per liter.2.5.Decolorization determinationDecolorization of each dye was followed by monitoring changes in its absorption spectrum(200to700nm)using a Shimadzu1201spectrophotometer and comparing the re-sults to those of the respective controls.3.ResultsIn solid media for8days,P.chrysosporium decolorized, to some extent,amaranth,new coccine,orange G and tar-trazine.P.sajorcaju totally decolorized amaranth,new coc-cine and orange G,but only grew on the solid medium containing tartrazine that was not visibly decolorized.In liquid culture,the decolorization of the dye solution could be due to adsorption by the fungal biomass or bio-degradation.When degradation occurred,there was either complete removal of the major visible light absorbance peak or a significant spectral change(e.g.development of a new peak).Amaranth and new coccine were totally decolorized by both fungi(Table1).P.chrysosporium totally removed the color from orange G and60%of tartrazine,while P.sajor-caju decolorized50%of orange G and a maximum of20% of tartrazine.During the decolorization of the dyes,the spectra showed an increase in absorbance in the UV(331nm)of around 10%for P.chrysosporium and150%for P.sajorcaju in the presence of amaranth.In the presence of tartrazine,the increase(307nm)was about350%for P.chrysosporium and200%for P.sajorcaju.In the presence of new coccine, the increase was about25%for both fungi.No increase in the UV absorbance was observed for the supernatant sam-ples of cultures grown in orange G as the carbon source.The decolorization was shown not to be due to any effects of pH474 E.P.Chagas,L.R.Durrant/Enzyme and Microbial Technology29(2001)473–477on the dyes,since the pH of the cultures did not alter during growth,remaining around 5.5for P.chrysosporium and 4.5to 5.0for P.sajorcaju.P.chrysosporium achieved a maximum tartrazine decol-orization rate,suddenly on the 7th day,while P.sajorcaju showed a lower decolorization,attaining a maximum (20%)on the 4th day (Fig.1).However,P.sajorcaju rapidly decolorized amaranth,achieving the maximum in 4days,while P.chrysosporium was slower and the total decolor-ization was completed in 8days.Possibly,the difference in the decolorization pattern between the two fungi could be associated with the establishment of the secondary metab-olism.In this case,decolorization by P.chrysosporium would only occur well after this fungus entered its second-ary phase of growth (after the 3rd day of incubation),whereas for P.sajorcaju decolorization did not seem to be dependent on the establishment of its secondary metabo-lism.Growth of both fungi as measured by dry weight was essentially complete after 3days in the medium containing amaranth,when P.chrysosporium and P.sajorcaju reacheda maximum of 31mg and 30mg of dry weight per 50mL of growth medium,respectively.In the presence of tar-trazine,a maximum of 25mg and 26mg was produced respectively by P.chrysosporium and P.sajorcaju after four days of growth.Growth in the medium containing no dye (control)stopped by the 2nd day of incubation and was negligible (4.5mg for P.chrysosporium and 5.2mg for P.sajorcaju ).Neither fungus showed lignin peroxidase or veratryl al-cohol oxidase activities,suggesting that these enzymes may not be involved in the decolorization of the dyes used here.Manganese-peroxidase and -glucosidase may be involved in the decolorization of the dyes by P.chrysosporium,whereas in P.sajorcaju laccase active toward o-dianisidine and glucose-1-oxidase might participate in the decoloriza-tion process (Fig.2).4.DiscussionDifferences have been observed in the ability of the two fungal strains to decolorize azo dyes.P.chrysosporium was able to ef ficiently decolorize amaranth,new coccine and orange G but only 60%of the tartrazine ’s color.Although P.sajorcaju ef ficiently decolorized amaranth and new coc-cine,orange G was only partly decolorized (decoloriza-tion Ͻ50%)and tartrazine was very poorly decolorized.Orange G has an aromatic ring and two sulphonic groups less than amaranth.However,the latter was more easily degraded.Small structural differences can affect decolor-ization owing to differences in electron distribution,charge density and steric factors [15].Tartrazine was the dye that was least decolorized by both fungi.No growth was observed when tartrazine concentra-tions higher than 10mg/liter were used,indicating that an inhibition mechanism might be taking place.The highest activities of MnP and -glucosidase in P.chrysosporium cultures indicate that these two enzymes may play an important role in the degradation of these dyes.It is interesting that only P.chrysosporium produced MnP activity,and degraded tartrazine and orange G more exten-sively than P.sajorcaju.Our results showed that P.sajorcaju presented the high-est GOD activity on the 2nd day of growth.This fungus did not produce either LiP or VAO,suggesting that the onset of degradation might be caused either by free radicals gener-ated by the H 2O 2produced by GOD activity or by laccase activity [16].Fu et al.(1997)[17]suggested that laccase and MnP are the main lignin degrading enzymes.It is interesting that P.sajorcaju produced a laccase active toward o -diani-sidine with maximum activity coinciding with a high in-crease in decolorization (2nd day),but no MnP activity,and was able to ef ficiently degrade amaranth.A laccase active toward syringaldazine was also present in the culture super-natants of both fungi and could be either the same enzyme showing varying activities toward different substrates or aTable 1Decolorization (%)of amaranth,new coccine,orange G and tartrazine at the maximum absorbance (522,506,475and 428nm respectively)by Phanerochaete chrysosporium (PC)and Pleurotus sajorcaju (020)on the 8th day of growth Fungi Dye Decolorization %PCAmaranth 98,5New Coccine 95,0Orange G 96,8Tartrazine 60,0020Amaranth 97,0New coccine 96,5Orange G 47,5Tartrazine20,0Chagas and Durrant,Decolorization of azo dyes.Fig.1.Time course for the decolorization of amaranth (ƒ)and tartrazine ({)by Phanerochaete chrysosporium and for amaranth (F )and tartrazine (s )by Pleurotus sajorcaju over 8days in liquid culture under shaking conditions.475E.P.Chagas,L.R.Durrant /Enzyme and Microbial Technology 29(2001)473–477second distinct laccase.The results obtained here,however,do not indicate any correlation between laccase (S)and decolorization of the dyes for either fungus.The enzymatic activity peak for CBQ was observed from the 6th day on in both cultures,suggesting that this enzyme could be preventing the repolymerization of the compounds produced by the action of the other enzymes [18].In general,P.sajorcaju showed enzymatic activities ear-lier than P.chrysosporium,and also reached its highest decolorization earlier,indicating that their ligninolytic sys-tem is differently triggered.Our results indicate that these two white-rot fungi could be used in bioprocesses to remove color from industrial ef fluents or to treat colored solid residues.The ability of white-rot fungi to degrade a wide variety of environmentally persistent pollutants indicates their po-tential use in anti-pollution treatments.However,only a better understanding of the mechanisms used by these fungi will allow the development of technologies to apply theseorganisms to the cleaning-up of aquatic and terrestrial en-vironments.AcknowledgmentE.P.Chagas is grateful to FAPESP for financial support.References[1]Marmion DM.Handbook of U.S.colorants.3rd ed.New York:JohnWiley &Sons,Inc.,1991(573p).[2]Combes RD,Haveland-Smith RB.A review of the genotoxicity offood,drug,and cosmetic colours,and other azo,triphenylmethane,and xanthene dyes.Mut Res 1982;98(2):101–248.[3]Capalash N,Sharma,P.Biodegradation of textile azo-dyes by Phan-erochaete chrysosporium .World J Microbiol Biotechnol 1992;8:309–12.[4]Paszczynski A,Pasti-Grigsby MB,Goszczynski S,Crawford RL,Crawford DL.Mineralization of sulfonated azo dyes andsulfanilicFig.2.Time course for production of enzymes by Phanerochaete chrysosporium in the presence of amaranth (ƒ)and tartrazine ({)and Pleurotus sajorcaju with amaranth (F )and tartrazine (s )for an 8-day period under shaking conditions.476 E.P.Chagas,L.R.Durrant /Enzyme and Microbial Technology 29(2001)473–477acid by Phanerochaete chrysosporium and Streptomyces chromofus-cus.Appl Environ Microbiol1992;58(11):3598–604.[5]Chivukula M,Renganathan V.Phenolic azo dyes oxidation by lac-case from Pyricularia oryzae.Appl Environ Microbiol1995;61(12): 4374–7.[6]Wong PK,Yuen PY.Decolorization and biodegradation of methylred by Klebsiella pneumoniae RS-13.Wat Res1996;30(7):1736–44.[7]Cripps C,Bumpus JA,Aust SD.Biodegradation of azo and hetero-cyclic dyes by Phanerochaete chrysosporium.Appl Environ Micro-biol1990;56(4):1114–8.[8]Schliephake K,Lonergan GT,Jones CL,Mainwaring DE.Decolour-ization of a pigment plant effluent by Pycnoporus cinnabarinus in a packed-red bioreactor.Biotech.Lett1993;15(1):1185–8.[9]Tien M,Kirk TK.Lignin peroxidase of Phanerochaete chrysospo-rium.Meth Enzymol1988;161:238–49.[10]Herrera AEM.Produc¸a˜o e caracterizac¸a˜o parcial de um composto debaixa massa molecular com atividade fenoloxida´sica de Thermoascus aurantiacus.Campinas,SP,Brazil,.(Ph.D.Thesis,Universidade Es-tadual de Campinas),1995.[11]Kuwahara M,Glen JK,Morgan MA,Gold MH.Separation andcharacterization of two extracellular H2O2dependent oxidase fromligninolytic cultures of Phanerochaete chrysosporium.FEBS Lett1984;169:247–50.[12]Kelley RL,Reddy A.Glucose-oxidase of Phanerochaete chrysospo-rium.Meth Enzymol1988;161:307–16.[13]Jafelice LRS,Wiseman A,Goldfarb PS.Sequential appearance of-glucosidase and lignin perosidase in the exocellularfluid of astacionary phase culture of Phanerochaete chrysosporium.BiochemSoc Trans1990;16:369–70.[14]Westermark U,Eriksson K-E.Carbohydrate enzymic quinone reduc-tion during lignin degradation.Acta Chem Scand B1974;28:204–8.[15]Knapp JS,Newby PS,Reece LP.Decolorization of dyes by wood-rotting basidiomycete fungi.Enzyme Microb Technol1995;17:664–8.[16]Tuor U,Winterhalter K,Fiechter A.Enzymes of white-rot fungiinvolved in lignin degradation and ecological determinants for wooddecay.J Biotechnol1995;41:1–17.[17]Fu SY,Yu H,Buswell JA.Effect of nutrient nitrogen and manganeseon manganese peroxidase and laccase production by Pleurotus sajor-caju.FEMS Microbiol Lett1997;147:133–7.[18]Ander P.The cellobiose-oxidising enzyme CBQ and CBO as relatedto lignin and cellulose degradation.A review.FEMS Microbiol Rev1994;13:297–311.477E.P.Chagas,L.R.Durrant/Enzyme and Microbial Technology29(2001)473–477。
生物科学论文中英文资料外文翻译文献
Carotenoid Biosynthetic Pathway in the Citrus Genus: Number of Copies and Phylogenetic Diversity of SevenGeneThe first objective of this paper was to analyze the potential role of allelic variability of carotenoid biosynthetic genes in the interspecifi diversity in carotenoid composition of Citrus juices. The second objective was to determine the number of copies for each of these genes. Seven carotenoid biosynthetic genes were analyzed using restriction fragment length polymorphism (RFLP) and simple sequence repeats (SSR) markers. RFLP analyses were performed with the genomic DNA obtained from 25 Citrus genotypes using several restriction enzymes. cDNA fragments of Psy, Pds, Zds, Lcyb, Lcy-e, Hy-b, and Zep genes labeled with [R-32P]dCTP were used as probes. For SSR analyses, two primer pairs amplifying two SSR sequences identified from expressed sequence tags (ESTs) of Lcy-b and Hy-b genes were designed. The number of copies of the seven genes ranged from one for Lcy-b to three for Zds. The genetic diversity revealed by RFLP and SSR profiles was in agreement with the genetic diversity obtained from neutral molecμLar markers. Genetic interpretation of RFLP and SSR profiles of four genes (Psy1, Pds1, Lcy-b, and Lcy-e1) enabled us to make inferences on the phylogenetic origin of alleles for the major commercial citrus species. Moreover, the resμLts of our analyses suggest that the allelic diversity observed at the locus of both of lycopene cyclase genes, Lcy-b and Lcy-e1, is associated with interspecific diversity in carotenoid accumμLation in Citrus. The interspecific differences in carotenoid contents previously reported to be associated with other key steps catalyzed by PSY, HY-b, and ZEP were not linked to specific alleles at the corresponding loci.KEYWORDS: Citrus; carotenoids; biosynthetic genes; allelic variability; phylogeny INTRODUCTIONCarotenoids are pigments common to all photosynthetic organisms. In pigment-protein complexes, they act as light sensors for photosynthesis but also prevent photo-oxidat ion induced by too strong light intensities. In horticμLtural crops, they play a major role in fruit, root, or tuber coloration and in nutritional quality. Indeed some of these micronutrients are precursors of vitamin A, an essential component of human and animal diets. Carotenoids may also play a role in chronic disease prevention (such as certain cancers), probably due to their antioxidant properties. The carotenoid biosynthetic pathway is now well established. Carotenoids are synthesized in plastids by nuclear-encoded enzymes. The immediate precursor of carotenoids (and also of gibberellins, plastoquinone, chlorophylls,phylloquinones, and tocopherols) is geranylgeranyl diphosphate (GGPP). In light-grown plants, GGPP is mainly derivedcarotenoid, 15-cis-phytoene. Phytoene undergoes four desaturation reactions catalyzed by two enzymes, phytoene desaturase (PDS) and β-carotene desaturase (ZDS), which convert phytoene into the red-colored poly-cis-lycopene. Recently, Isaacson et al. and Park et al. isolated from tomato and Arabidopsis thaliana, respectively, the genes that encode the carotenoid isomerase (CRTISO) which, in turn, catalyzes the isomerization of poly-cis-carotenoids into all-trans-carotenoids. CRTISO acts on prolycopene to form all-trans lycopene, which undergoes cyclization reactions. Cyclization of lycopene is a branching point: one branch leads to β-carotene (β, β-carotene) and the other toα-carotene (β, ε-carotene). Lycopene β-cyclase (LCY-b) then converts lycopene intoβ-carotene in two steps, whereas the formation of α-carotene requires the action of twoenzymes, lycopene ε- cyclase (LCY-e) and lycopene β-cyclase (LCY-b). α- carotene is converted into lutein by hydroxylations catalyzed by ε-carotene hydroxylase (HY-e) andβ-carotene hydroxylase (HY-b). Other xanthophylls are produced fromβ-carotene with hydroxylation reactions catalyzed by HY-b and epoxydation catalyzed by zeaxanthin epoxidase (ZEP). Most of the carotenoid biosynthetic genes have been cloned and sequenced in Citrus varieties . However, our knowledge of the complex regμLation of carotenoid biosynthesis in Citrus fruit is still limited. We need further information on the number of copies of these genes and on their allelic diversity in Citrus because these can influence carotenoid composition within the Citrus genus.Citrus fruit are among the richest sources of carotenoids. The fruit generally display a complex carotenoid structure, and 115 different carotenoids have been identified in Citrus fruit. The carotenoid richness of Citrus flesh depends on environmental conditions, particμLarly on growing conditions and on geogr aphical origin . However the main factor influencing variability of caro tenoid quality in juice has been shown to be genetic diversity. Kato et al. showed that mandarin and orange juices accumμLated high levels of β-cryptoxanthin and violaxanthin, respectively, whereas mature lemon accumμLated extremely low levels of carotenoids. Goodner et al. demonstrated that mandarins, oranges, and their hybrids coμLd be clearly distinguished by their β-cryptoxanthin contents. Juices of red grapefruit contained two major carotenoids: lycopene and β-carotene. More recently, we conducted a broad study on the organization of the variability of carotenoid contents in different cμLtivated Citrus species in relation with the biosynthetic pathway . Qualitative analysis of presence or absence of the different compounds revealed three main clusters: (1) mandarins, sweet oranges, and sour oranges; (2) citrons, lemons, and limes; (3) pummelos and grapefruit. Our study also enabled identification of key steps in the diversification of the carotenoid profile. Synthesis of phytoene appeared as a limiting step for acid Citrus, while formation of β-carotene and R-carotene from lycopene were dramatically limited in cluster 3 (pummelos and grapefruit). Only varieties in cluster 1 were able to produce violaxanthin. In the same study , we concluded that there was a very strong correlation between the classification of Citrus species based on the presence or absence of carotenoids (below,this classification is also referred to as the organization of carotenoid diversity) and genetic diversity evaluated with biochemical or molecμLar markers such as isozymes or randomLy amplified polymorphic DNA (RAPD). We also concluded that, at the interspecific level, the organization of the diversity of carotenoid composition was linked to the global evolution process of cμLtivated Citrus rather than to more recent mutation events or human selection processes. Indeed, at interspecific level, a correlation between phenotypic variability and genetic diversity is common and is generally associated with generalized gametic is common and is generally associated with generalized gametic disequilibrium resμLting from the history of cμLtivated Citrus. Thus from numerical taxonomy based on morphological traits or from analysis of molecμLar markers , all authors agreed on the existence of three basic taxa (C. reticμLata, mandarins; C. medica, citrons; and C. maxima, pummelos) whose differentiation was the resμLt of allopatric evolution. All other cμLtivated Citrus specie s (C. sinensis, sweet oranges; C. aurantium, sour oranges; C. paradisi, grapefruit; and C. limon, lemons) resμLted from hybridization events within this basic pool except for C. aurantifolia, which may be a hybrid between C. medica and C. micrantha .Our p revious resμLts and data on Citrus evolution lead us to propose the hypothesis that the allelic variability supporting the organization of carotenoid diversity at interspecific level preceded events that resμLted in the creation of secondary species. Such molecμLar variability may have two different effects: on the one hand, non-silent substitutions in coding region affect the specific activity of corresponding enzymes of the biosynthetic pathway, and on the other hand, variations in untranslated regions affect transcriptional or post-transcriptional mechanisms.There is no available data on the allelic diversity of Citrus genes of the carotenoid biosynthetic pathway. The objective of this paper was to test the hypothesis that allelic variability of these genes partially determines phenotypic variability at the interspecific level. For this purpose, we analyzed the RFLPs around seven genes of the biosynthetic pathway of carotenoids (Psy, Pds, Zds, Lcy-b, Lcy-e, Hy-b, Zep) and the polymorphism of two SSR sequences found in Lcy-b and Hy-b genes in a representative set of varieties of the Citrus genus already analyzed for carotenoid constitution. Our study aimed to answer the following questions: (a) are those genes mono- or mμLtilocus, (b) is the polymorphism revealed by RFLP and SSR markers in agreement with the general history of cμLtivated Citrus thus permitting inferences about the phylogenetic origin of genes of the secondary species, and (c) is this polymorphism associated with phenotypic (carotenoid compound) variations.RESΜLTS AND DISCUSSIONGlobal Diversity of the Genotype Sample Observed by RFLP Analysis. RFLP analyses were performed using probes defined from expressed sequences of seven major genes of the carotenoid biosynthetic pathway . One or two restriction enzymes were used for each gene. None of these enzymes cut the cDNA probe sequence except HindIII for the Lcy-e gene. Intronic sequences and restriction sites on genomic sequences werescreened with PCR amplification using genomic DNA as template and with digestion of PCR products. The resμLts indicated the absence of an intronic sequence for Psy and Lcy-b fragments. The absence of intron in these two fragments was checked by cloning and sequencing corresponding genomic sequences (data not shown). Conversely, we found introns in Pds, Zds, Hy-b, Zep, and Lcy-e genomic sequences corresponding to RFLP probes. EcoRV did not cut the genomic sequences of Pds, Zds, Hy-b, Zep, and Lcy-e. In the same way, no BamHI restriction site was found in the genomic sequences of Pds, Zds, and Hy-b. Data relative to the diversity observed for the different genes are presented in Table 4. A total of 58 fragments were identified, six of them being monomorphic (present in all individuals). In the limited sample of the three basic taxa, only eight bands out of 58 coμLd not be observed. In the basic taxa, the mean number of bands per genotype observed was 24.7, 24.7, and 17 for C. reticμLata, C. maxima, and C. medica, respectively. It varies from 28 (C. limettioides) to 36 (C. aurantium) for the secondary species. The mean number of RFLP bands per individual was lower for basic taxa than for the group of secondary species. This resμLt indicates that secondary species are much more heterozygous than the basic ones for these genes, which is logical if we assume that the secondary species arise from hybridizations between the three basic taxa. Moreover C. medica appears to be the least heterozygous taxon for RFLP around the genes of the carotenoid biosynthetic pathway, as already shown with isozymes, RAPD, and SSR markers.The two lemons were close to the acid Citrus cluster and the three sour oranges close to the mandarins/sweet oranges cluster. This organization of genetic diversity based on the RFLP profiles obtained with seven genes of the carotenoid pathway is very similar to that previously obtained with neutral molecμLar markers such as genomic SSR as well as the organization obtained with qualitative carotenoid compositions. All these resμLts suggest that the observed RFLP and SSR fragments are good phylogenetic markers. It seems consistent with our basic hypothesis that major differentiation in the genes involved in the carotenoid biosynthetic pathway preceded the creation of the secondary hybrid species and thus that the allelic structure of these hybrid species can be reconstructed from alleles observed in the three basic taxa.Gene by Gene Analysis: The Psy Gene. For the Psy probe combined with EcoRV or BamHI restriction enzymes, five bands were identified for the two enzymes, and two to three bands were observed for each genotype. One of these bands was present in all individuals. There was no restriction site in the probe sequence. These resμLts lead us to believe that Psy is present at two loci, one where no polymorphism was found with the restriction enzymes used, and one that displayed polymorphism. The number of different profiles observed was six and four with EcoRV and BamHI, respectively, for a total of 10 different profiles among the 25 individuals .Two Psy genes have also been found in tomato, tobacco, maize, and rice . Conversely, only one Psy gene has been found in Arabidopsis thaliana and in pepper (Capsicum annuum), which also accumμLates carotenoids in fruit. According to Bartley and Scolnik, Psy1 was expressed in tomato fruit chromoplasts, while Psy2 was specific to leaf tissue. In the same way, in Poaceae (maize, rice), Gallagher et al. found that Psy gene was duplicated and that Psy1 and notPsy2 transcripts in endosperm correlated with endosperm carotenoid accumμLation. These resμLts underline the role of gene duplication and the importance of tissue-specific phytoene synthase in the regμLation of carotenoid accumμLation.All the polymorphic bands were present in the sample of the basic taxon genomes. Assuming the hypothesis that all these bands describe the polymorphism at the same locus for the Psy gene, we can conclude that we found allelic differentiation between the three basic taxa with three alleles for C. reticμLata, four for C. maxima, and one for C. medica.The alleles observed for the basic taxa then enabled us to determine the genotypes of all the other species. The presumed genotypes for the Psy polymorphic locus are given in Table 7. Sweet oranges and grapefruit were heterozygous with one mandarin and one pummelo allele. Sour oranges were heterozygous; they shared the same mandarin allele with sweet oranges but had a different pummelo allele. Clementine was heterozygous with two mandarin alleles; one shared with sweet oranges and one with “Willow leaf” mandarin. “Meyer” lemon was heterozygous, with the mandarin allele also found in sweet oranges, and the citron allele. “Eureka”lemon was also heterozygous with the same pummelo allele as sour oranges and the citron allele. The other acid Citrus were homozygous for the citron allele.The Pds Gen. For the Pds probe combined with EcoRV, six different fragments were observed. One was common to all individuals. The number of fragments per individual was two or three. ResμLts for Pds led us to believe that this gene is present at two loci, one where no polymorphism was found with EcoRV restriction, and one displaying polymorphism. Conversely, studies on Arabidopsis, tomato, maize, and rice showed that Pds was a single copy gene. However, a previous study on Citrus suggests that Pds is present as a low-copy gene family in the Citrus genome, which is in agreement with our findings.The Zds Gene. The Zds profiles were complex. Nine and five fragments were observed with EcoRV and BamHI restriction, respectively. For both enzymes, one fragment was common to all individuals. The number of fragments per individual ranged from two to six for EcoRV and three to five for BamHI. There was no restriction site in the probe sequence. It can be assumed that several copies (at least three) of the Zds gene are present in the Citrus genome with polymorphism for at least two of them. In Arabidopsis, maize, and rice, like Pds, Zds was a single-copy gene .In these conditions and in the absence of analysis of controlled progenies, we are unable to conduct genetic analysis of profiles. However it appears that some bands differentiated the basic taxa: one for mandarins, one for pummelos, and one for citrons with EcoRV restriction and one for pummelos and one for citrons with BamHI restriction. Two bands out of the nine obtained with EcoRV were not observed in the samples of basic taxa. One was rare and only observed in “Rangpur” lime. The other was found in sour oranges, “V olkamer” lemon,and “Palestine sweet” lime suggesting a common ancestor for these three genotypes.This is in agreement with the assumption of Nicolosi et al. that “V olkamer” lemon resμLts from a complex hybrid combination with C. aurantium as one parent. It will benecessary to extend the analysis of the basic taxa to conclude whether these specific bands are present in the diversity of these taxa or resμLt from mutations after the formation of the secondary species.The Lcy-b Gene with RFLP Analysis.After restriction with EcoRV and hybridization with the Lcy-b probe, we obtained simple profiles with a total of four fragments. One to two fragments were observed for each individual, and seven profiles were differentiated among the 25 genotypes. These resμLts provide evidence that Lcy-b is present at a single locus in the haploid Citrus genome. Two lycopene β-cyclases encoded by two genes have been identified in tomato. The B gene encoded a novel type of lycopene β-cyclase whose sequence was similar to capsanthin-capsorubin synthase. The B gene expressed at a high level in βmutants was responsible for strong accumμLation ofβ-carotene in fruit, while in wild-type tomatoes, B was expressed at a low level.The Lcy-b Gene with SSR Analysis. Four bands were detected at locus 1210 (Lcy-b gene). One or two bands were detected per variety confirming that this gene is mono locus. Six different profiles were observed among the 25 genotypes. As with RFLP analysis, no intrataxon molecμLar polymorphism was found within C. Paradisi, C. Sinensis, and C. Aurantium.Taken together, the information obtained from RFLP and SSR analyses enabled us to identify a complete differentiation among the three basic taxon samples. Each of these taxons displayed two alleles for the analyzed sample. An additional allele was identified for “Mexican” l ime. The profiles for all secondary species can be reconstructed from these alleles. Deduced genetic structure is given in. Sweet oranges and clementine were heterozygous with one mandarin and one pummelo allele. Sour oranges were also heterozygous sharing the same mandarin allele as sweet oranges but with another pummelo allele. Grapefruit were heterozygous with two pummelo alleles. All the acid secondary species were heterozygous, having one allele from citrons and the other one from mandarins except for “Mexican” lime, which had a specific allele.柑桔属类胡萝卜素生物合成途径中七个基因拷贝数目及遗传多样性的分析摘要：本文的首要目标是分析类胡萝卜素生物合成相关等位基因在发生变异柑橘属类胡萝卜素组分种间差异的潜在作用；第二个目标是确定这些基因的拷贝数。
2020年(生物科技行业)分子生物学中英文对照
（生物科技行业）分子生物学中英文对照acetylCoA/乙酰辅酶A壹种小分子的水溶性代谢产物,由和辅酶A相连的乙酰基组成,产生于丙酮酸、脂肪酸及氨基酸的氧化过程;其乙酰基在柠檬酸循环中被转移到柠檬酸。
actin/肌动蛋白,肌纤蛋白富含于真核细胞中的结构蛋白,和许多其他蛋白相互作用。
其球形单体(G2肌动蛋白)聚合形成肌动蛋白纤丝(F2肌动蛋白)。
在肌肉细胞收缩时F2肌动蛋白和肌球蛋白相互作用。
activationenergy/活化能(克服障碍以)启动化学反应所需的能量投入。
降低活化能,可增加酶的反应速率。
activesite/活性中心,活性部位酶分子上和底物结合及进行催化反应的区域。
activetransport/主动转运离子或小分子逆浓度梯度或电化学梯度的耗能跨膜运动。
由ATP耦联水解或另壹分子顺其电化学梯度的转运提供能量。
adenylylcyclase/酰苷酸环化酶催化由ATP生成环化腺苷酸(cAMP)的膜附着酶。
特定配体和细胞表面的相应受体结合引发该酶的激活且使胞内的cAMP升高。
allele/等位基因位于同源染色体上对应部位的基因的俩种或多种可能形式之壹。
allosterictransition/变构转换小分子和蛋白质上特定调节部位相结合所引起的蛋白质之三级及(或)四级结构的改变,其活性随之发生变化。
多亚单位酶的变构调节很普遍。
alpha(α)helix/α螺旋常见的蛋白质二级结构,其氨基酸线性序列叠为右旋螺旋,借助主链上的羧基和酰胺基间的氢键维持稳定。
aminoacyl2tRNA/氨酰转移核糖核酸用于蛋白合成的氨基酸的激活形式,含有借高能酯键和tRNA分子上3’2羟基相结合的氨基酸。
amphipathic/俩亲的,兼性的指既有亲水性部分又有疏水性部分的分子或结构。
anaphase/(细胞分裂)后期姐妹染色体(或有丝分裂期的成对同源物)裂开且分别(分离)朝纺锤体俩极移动的有丝分裂期。
anticodon/反密码子和mRNA的密码子互补的tRNA中三个核苷酸的序列,蛋白合成过程中,密码子和反密码子之间的碱基配对使携带增长肽链的新增对等氨基酸的tRNA排齐。
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微生物技术分子生物技术中英文资料外文翻译文献A/O法活性污泥中氨氧化菌群落的动态与分布摘要：我们研究了在厌氧—好氧序批式反应器（SBR）中氨氧化菌群落（AOB）和亚硝酸盐氧化菌群落（NOB）的结构活性和分布。
在研究过程中，分子生物技术和微型技术被用于识别和鉴定这些微生物。
污泥微粒中的氨氧化菌群落结构大体上与初始的接种污泥中的结构不同。
与颗粒形成一起，由于过程条件中生物选择的压力，AOB的多样性下降了。
DGGE测序表明，亚硝化菌依然存在，这是因为它们能迅速的适应固定以对抗洗涤行为。
DGGE更进一步的分析揭露了较大的微粒对更多的AOB种类在反应器中的生存有好处。
在SBR反应器中有很多大小不一的微粒共存，颗粒的直径影响这AOB和NOB的分布。
中小微粒（直径<0.6mm）不能限制氧在所有污泥空间的传输。
大颗粒（直径>0.9mm）可以使含氧量降低从而限制NOB的生长。
所有这些研究提供了未来对AOB微粒系统机制可能性研究的支持。
关键词：氨氧化菌（AOB），污泥微粒，菌落发展，微粒大小，硝化菌分布，发育多样性1.简介在浓度足够高的条件下，氨在水环境中对水生生物有毒，并且对富营养化有贡献。
因此，废水中氨的生物降解和去除是废水处理工程的基本功能。
硝化反应，将氨通过硝化转化为硝酸盐，是去除氨的一个重要途径。
这是分两步组成的，由氨氧化和亚硝酸盐氧化细菌完成。
好氧氨氧化一般是第一步，硝化反应的限制步骤：然而，这是废水中氨去除的本质。
对16S rRNA的对比分析显示，大多数活性污泥里的氨氧化菌系统的跟ß-变形菌有关联。
然而，一系列的研究表明，在氨氧化菌的不同代和不同系有生理和生态区别，而且环境因素例如处理常量，溶解氧，盐度，pH，自由氨例子浓度会影响氨氧化菌的种类。
因此，废水处理中氨氧化菌的生理活动和平衡对废水处理系统的设计和运行是至关重要的。
由于这个原因，对氨氧化菌生态和微生物学更深一层的了解对加强处理效果是必须的。
当今，有几个进阶技术在废水生物处理系统中被用作鉴别、刻画微生物种类的有价值的工具。
目前，分子生物技术的应用能提供氨氧化菌群落的详细分类说明。
如今，主要由于其细胞固定策略，好氧污泥颗粒处理已经成为传统废水处理的替代工艺。
颗粒有更加彻底的紧密结构和快速适应速率。
因此，颗粒污泥系统比传统活性污泥法有更高的混合悬浮固体浓度浓度(MLSS)和更长的污泥龄(SRT)。
更长的污泥龄能提供足够长的时间让时代时间长的微生物生长(例如氨氧化菌)。
有些研究表示，硝化颗粒可以在富铵离子废水中培养出来，并且颗粒的直径很小。
其他研究报告说，大直径颗粒已经在序批式反应器(SBR)中人工合成的有机废水里培育出来了。
污泥颗粒里的大量不同微生物共存，并去除COD和氮磷。
然而，对于直径大于0.6mm的大颗粒来说，由于氧传递被限制不能到达颗粒核心，外部好氧壳和内部厌氧地带共存。
这些特性表明，大颗粒污泥内部环境不适合氨氧化菌的生长。
有些研究表明，颗粒大小和密度导致了氨氧化菌、亚硝酸氧化菌和反硝化菌的分布和优势种群。
虽然不少研究力求评估废水处理系统中氨氧化菌的生态生理，但是至今仍然被污泥颗粒化过程的水力学、分布、氨氧化菌群落的数量化限制着。
2.原理和方法2.1反应器设置和操作污泥颗粒被接种在有效体积为4L的实验室规模的SBR里。
反应器有效直径和高度分别为10cm和51cm。
水力停留时间设为8h。
来自全尺寸污泥处理设置(中国天津污水处理厂)的活性污泥被作为反应器的种污泥，其MLSS初始浓度为3876mg/L。
反应器操作6小时为一循环，由2分钟的进水时间，90分钟厌氧混合，240反正抛弃阶段和5分钟出水阶段组成。
在20天80个SBR循环后，污泥沉降时间逐渐从10分钟降到5分钟，并且只有沉降速度大禹4.5m/h的颗粒才能在反应器中停留。
入流中的主要化合物包括NaAc(450mg/L)，NH4Cl(100mg/L)，(NH4)2SO4(10mg/L)，KH2PO4(20mg/L)，MgSO4·7H2O(50mg/L)，KCl(20mg/L)，CaCl2(20 mg/L)，FeSO4·7H2O(1mg/L)，pH 7.0-7.5，and 0.1 mg/L元素示踪剂。
分析方法-TOC、TN、TP、MLSS、SVI都根据标准方法定期检测。
污泥大小分布由筛法决定。
4个干净的直径为5cm钢制筛，筛孔直径分别0.9,0.6,0.45,和0.2mm，这4个筛子被全程监控。
用友刻度的圆柱从反应器中取100mL的污泥，然后放到0.9mm筛孔的筛子上。
随后用蒸馏水冲洗，直径小于0.9mm的颗粒通过这个筛子，到达筛孔更小的筛子上。
冲洗过程要重复几次，以分开污泥团。
不同面上收集到的颗粒恢复用蒸馏水反冲洗。
每一部分都手机在不同的烧杯里，然后用量化的滤纸过滤来测定TSS。
一旦留在各个筛子上TSS的数量确定了，就可以确定不同大小的颗粒占污泥总重的比例了。
2.2DNA提取和PCR-DGGE来自大约8mg的MLSS种的污泥被转化成1.5mL的Eppendorf管，然后在14000g条件下离心10分钟。
移除上清液，向其中加入1mL磷酸钠缓冲液，然后在无菌条件下研磨以分离颗粒。
使用E.Z.N.A.Soil DNA工具，离心物种DNA染色体被分离。
为了放大氨氧化菌特征16s rRNA来进行DGGE，一个巢式PCR被用为先前描述。
30µl的巢式PCR放大剂被加载并被在聚丙烯酰胺凝胶上的加了线性分布为35%-55%的变性剂DGGE分开。
这个胶体在维持60度、140V、1×TAE缓冲液中(通用突变检测系统)运行 6.5h。
电泳结束后，银染色和胶体的发展表现正如Sanguinetti所表述。
接下来是空气干燥和用凝胶成像分析系统扫描。
凝胶扫描图像用Quantity One分析，版本号4.31。
成对群落相似性的色子指数是计算评估氨氧化菌群落在DGGE中线路相似性的。
这个用Quantity One测出的指数范围从0%(无共同频带)到100%(频带相同)。
Shannon多样性指数（H）是用来衡量将一个菌群中每个菌种的丰富度和比例加入考虑的微生物多样性。
H用下列等式计算：其中，ni/N表示i菌种占总群落的比例(i条带亮度在条带总亮度中的比例)。
微生物系统树图模板相似性使用Quantity One不用非加权配对组算术平均数（UPGMA法）算法就能计算出来。
突出的DGGE条带被切除并溶解在30mL Milli-Q水中过夜，温度维持4摄氏度。
在冷冻解冻3次后凝胶中的DNA被回收。
目标DNA片段的克隆及测序按照既定的方法（Zhang等，2010）进行。
2.3硝化细菌的分布为了调查AOB和NOB在颗粒中的空间分布，3种大小([0.2-0.45],[0.45-0.6],>0.9 mm)的颗粒在第180天被选定做FISH分析。
2mg的污泥样品被固定在在4摄氏度下的4％多聚甲醛溶液16-24 h，然后用磷酸钠缓冲液冲洗两次；样本分别在在50%，80%和100%的乙醇中脱水10分钟。
在室温下，将颗粒在乙醇—二甲苯体积比分别为3:1，1:1，1:3然后100%二甲苯的溶液中连续浸泡，每次10分钟后，颗粒中的乙醇然后完全被二甲苯取代。
随后，将颗粒在二甲苯与石蜡体积比为1:1的60度溶液中浸泡30分钟，接着再在100%石蜡溶液中浸泡30分钟，颗粒被石蜡嵌入。
在石蜡固化后，切为8mm厚的片，放置在涂了明胶的显微镜上。
将切片在二甲苯和乙醇中各浸泡30分钟，石蜡被去除，然后将切片干燥。
三个寡核苷酸探针被用于杂交：FITC标记为Nso190，指明了大多数AOB；TRITC标记为NIT3，指明了硝化sp。
所有的探针序列，杂交条件，以及洗涤条件都在表1中给出。
寡核苷酸的合成以及荧光标记都来自Takara公司。
杂交是在包含了各个标记了的探针(5ng µ/L)的46摄氏度度杂交缓冲液(0.9M NaCl,甲酰胺的百分比见表1，20mM Tris/ HCl，pH值8.0，0.01% SDS)下进行了2小时。
杂交后，未被结合的寡核苷酸由一个严格的洗涤步骤去除：在48度与洗涤液含有相同化合物的缓冲液中洗涤15分钟。
为了所有DNA的探测，DAPI被用甲醇最终稀释到浓度为1ng µ/L。
将切片用DAP-Iemethanol覆盖并保持恒温37度15分钟。
然后将切片用甲醇清洗一次，再用蒸馏水简单清洗，完了立刻空气干燥。
使用Vectashield(媒介实验室)以防止照片变白。
使用激光共聚焦显微镜来抓拍杂交图像(CLSM,Zeiss 710)。
每种颗粒大小的每个探头都各自一共拍了10张图像。
最后使用Adobe PhotoShop选出代表图像和最终图像的评价。
表1：用于不同大小颗粒的寡核苷酸探针图1：生物量和SVI10在整个操作过程中的变化3.结果3.1SBR性能及颗粒特征在启动阶段，反应器能高效去除TOC以及氨氮。
98%的氨氮和100%的TOC 分别在第3天和第5天从入流中被去除(图S2，S3)。
这一期间总氮和总磷的去除率不高，虽然总磷的去除率逐渐提高，在第33天达到100%(图S4)。
为了确定污泥颗粒的污泥体积指数，沉淀时间由10分钟代替30分钟，因为颗粒污泥在60分钟和5分钟后有一个相似的SVI数值。
接种污泥的SVI值是108.2Ml/g。
在连续操作中MLSS和SVI10的变化如图1所示。
污泥沉降性在设置阶段明显提升。
图2反应了污泥颗粒的慢速形成，从流动态到颗粒状态。
3.2DGGE技术分析：AOB的群落结构在污泥颗粒化中的变化巢式PCR的结果在图S1中显示。
在GSBR的操作中，较好显示的DGGE条带被在代表性点上得到，那些条带揭示AOB群落的结构在污泥颗粒化和稳定化过程中是动态的(图3)。
实验结束时的菌群结构与初始接种污泥的菌群结构是不同的。
AOB群落在第一天和GSBR操作的最后仅有40%的相似度，指明接种污泥和形成的颗粒污泥中AOB群落有重大变化。
通过计算Shannon指数H分析DGGE 模板得出的生物多样性见图5.图2：污泥中颗粒大小分布在操作过程中的变化图3：AOB群落在污泥颗粒化过程中DGGE分析(顶部表示取样时间)。
主要条带已用数字标出(条带1-15)在污泥接种阶段(在第38天前)，指数H由于反应器中一些菌种的消失明显下降。
虽然几种接种污泥中的优势菌种(条带2,7,10,11)得以保留，但是许多条带削弱或消失了(条带3,4,6,8,13,14,15)。
在第45天后，多样性指数趋于稳定，并且显示流动性变小(从0.72到0.82)。
模板条带相似性利用UPGMA程序分析。
UPGMA分析显示三个组菌落群相似度约为67%-78%，群体内部约为44%-62%。