微生物名词解释

GlossaryActinomycetes(放线菌，放线菌属) A group of filamentous, funguslike bacteria. active transport （主动运输） Nutrient transport method that requires carrier proteins in the membranes of the living cells and the expenditure of energy. adenovirus Noenveloped DNA virus; means of transmission is human-to-human via respiratory and ocular secretions.aerobe（需氧微生物）A microorganism that lives and grows in the presence of free).gaseous oxygen (O2aerobic respiration（需氧呼吸）Respiration in which the final electron acceptor in the electron transport chain is oxygen (O).2agar（琼脂）A polysaccharide found in seaweed and commonly used to prepare solid culture media.AIDS（艾滋病）Acquired immunodeficiency syndrome. The complex of signs and symptoms characteristic of the late phase of human immunodeficiency virus (HIV) infection.algae（藻类） Photosynthetic, plant-like organisms which generally lack the complex structure of plants; they may be single-celled or multicellular, and inhabit diverse habitats such as marine and freshwater environments, glaciers, and hot springs.Ames test（艾姆斯氏试验）A method for detecting mutagenic and potentially carcinogenic agents based upon the genetic alteration of nutritionally defective bacteria.ammonification（氨化作用） Phase of the nitrogen cycle in which ammonia is released from decomposing organic material.anaerobe（厌氧性微生物，厌氧菌） A microorganism that grows best, or exclusively, in the absence of oxygen.anaerobic respiration（无氧呼吸）Respiration in which the final electron acceptor in the electron transport chain is an inorganic molecule containing sulfate, nitrate, nitrite, carbonate, etc.antagonism（拮抗作用）Relationship in which microorganisms compete for survival in a common environment by taking actions that inhibit or destroy another organism.antibiotic（抗生素）A chemical substance from one microorganism that can inhibit or kill another microbe even in minute amounts.archaea（古生菌） Prokaryotic single-celled organisms of primitive origin that have unusual anatomy, physiology and genetics, and live in harsh habitats;when capitalized (Archaea) the term refers to one of the three domains of living organisms as proposed by Woese.arthrospore（分节孢子）A fungal spore formed by the septation and fragmentation of hyphae.ascospore （囊孢子，子囊孢子）A spore formed within a saclike cell (ascus) of Ascomycota following nuclear fusion and meiosis.ascus（子囊） Special fungal sac in which haploid spores are created. autoclave（高压锅） A sterilization chamber which allows the use of steam under pressure to sterilize materials. The most common temperature/pressure combination for an autoclave is 121℃and 15 psi.autotroph（自养生物） A microorganism that requires only inorganic nutrients and whose sole source of carbon is carbon dioxide.Bacillus（芽孢杆菌） Bacterial cell shape that is cylindrical (longer than it is wide).back-mutation（回复突变） A mutation which counteracts an earlier mutation, resulting in the restoration of the original DNA sequence.bacteria （细菌）Category of prokaryotes with peptidoglycan in their cell wails and a single, circular chromosome. This group of small cells is widely distributed in the earth’s habitats.Bacteria (plural of bacterium) When capitalized can refer to one of the three domains of living organisms proposed by Woese, containing all non- archaea prokaryotes.bacterial chromosome 细菌染色体A circular body in bacteria that contains the primary genetic material. Also called nucleoid.Bacteriophage噬菌体A virus that specifically infects bacteria.bacterium 杆菌属A tiny unicellular prokaryotic organism that usually reproduces by binary fission and usually has a peptidoglycan cell wall, has various shapes, and can be found in virtually any environment.basidiospore（芽孢） A sexual spore that arises from a basidium. Found in basidiomycota fungi.Bdellovibrio（蛭弧菌属） A bacterium that preys on certain other bacteria. It bores a hole into a specific host and inserts itself between the protoplast and the cell wall. There it elongates before subdividing into several cells and devouring the host cell.capsule蒴果In bacteria, the loose, gel-like covering or slime made chiefly of simple polysaccharides. This layer is protective and can be associated with virulence.Chemoautotroph华能自养生物An organism that relies upon inorganic chemicals for its energy and carbon dioxide for its carbon. Also called a chemolithotroph. chemoheterotroph华能异养生物Microorganisms that derive their nutritional needs from organic compounds.chemotaxis趋化性The tendency of organisms to move in response to a chemical gradient (toward an attractant or to avoid adverse stimuli).chitin 几丁质A polysaccharide similar to cellulose in chemical structure. This polymer makes up the horny substance of the exoskeletons of arthropods and certain fungi.chromosome染色体The tightly coiled bodies in cells that are the primary sites of genes.Clone无性繁殖 A colony of cells (or group of organisms) derived from a single cell (or single organism) by asexual reproduction. All units share identical characteristics. Also used as a verb to refer to the process of producinga genetically identical population of cells or genes.colony菌落 A macroscopic cluster of cells appearing on a solid medium, each arising from the multiplication of a single cell.commensalism共栖An unequal relationship in which one species derives benefit without harming the other.conjugation结合作用In bacteria, the contact between donor and recipient cells associated with the transfer of genetic material such as plasmids. Can involve special (sex) pili. Also a form of sexual recombination in ciliated protozoans.death phase死亡期End of the cell growth due to lack of nutrition, depletion of environment, and accumulation of wastes. Population of cells begins to die.decomposition分解The breakdown of dead matter and wastes into simple compounds, that can be directed back into the natural cycle of living things. diffusion扩散The dispersal of molecules, ions, or microscopic particles propelled down aconcentration gradient by spontaneous random motion to achieve a uniform distribution.diploid 二倍体Somatic cells having twice the basic chromosome number. One set in the pair is derived from the father, and the other from the mother. direct, or total cell count 细胞计数1. Counting total numbers of individual cells being viewed with magnification. 2. Counting isolated colonies of organisms growing on a plate of media as a way to determine population size. endospore内生孢子A small, dormant, resistant derivative of a bacterial cell that germinates under favorable growth conditions into a vegetative cell.The bacterial genera Bacillus and Clostridium are typical sporeformers. eubacteria 真细菌Term used for non-archaea prokaryotes, stands for "true bacteria"eukaryotic cell真核细胞A cell that differs from a prokaryotic cell chiefly by having a nuclear membrane (a well-defined nucleus), membrane-bounded subcellular organelles, and mitotic cell division.Eukarya真核生物One of the three domains (sometimes called superkingdoms) of living organisms, as proposed by Woese; contains all eukaryotic organisms. eutrophication富营养化The process whereby dissolved nutrients resulting from natural seasonal enrichment or industrial pollution of water cause overgrowth of algae and cyanobacteria to the detriment of fishand other large aquatic inhabitants.fermentation 发酵The extraction of energy through anaerobic degradation of substrates into simpler, reduced metabolites. In large industrial processes, fermentation can mean any use of microbial metabolism to manufacture organic chemicals or other products.fimbria 菌毛A short, numerous surface appendage on some bacteria that provides adhesion but not locomotion.flagellum鞭毛A structure that is used to propel the organism through a fluid environment.gene基因A site on a chromosome that provides information for a certain cell function. A specific segment of DNA that contains the necessary code to makea protein or RNA molecule.generation time代时Time required for a complete fission cycle－from parent cell to two new daughter cells. Also called doubling time.genome 基因组染色体组The complete set of chromosomes and genes in an organism. Genotype 基因型 The genetic makeup of an organism. The genotype is ultimately responsible for an organism's phenotype, or expressed characteristics. Gram stain革兰氏染色剂 A differential stain for bacteria useful in identification and taxonomy. Gram-positive organisms appear purple from crystal violet- mordant retention, whereas gram-negative organisms appear red after loss of crystal violet and absorbance of the safranin counterstain. growth curve生长曲线A graphical representation of the change in population size over time. This graph has four periods known as lag phase, exponential or log phase, stationary phase, and death phase.growth factor生长因子An organic compound such as a vitamin or amino acid that must be provided in the diet to facilitate growth. An essential nutrient. halophile好盐菌A microbe whose growth is either stimulated by salt or requiresa high concentration of salt for growth.haploid 单倍体Having a single set of unpaired chromosomes, such as occurs in gametes and certain microbes.host 宿主Organism in which smaller organisms or viruses live, feed, and reproduce.human immunodeficiency virus (HIV)艾滋病病毒A retro virus that causes acquired immunodeficiency syndrome (AIDS).intron 内含子The segments on split genes of eucaryotes that do not code for polypeptide. They can have regulatory functions. See exon.in vitro离体 Literally means "in glass," signifying a process or reaction occurring in an artificial environment, as in a test tube or culture medium. in vivo生物体内Literally means “in a living being,” signifying a process or reaction occurring in a living thing.Koch’s postulates科赫法则 A procedure to establish the specific cause of disease. In all cases of infection: ( 1 ) The agent must be found; (2) inoculations of a pure culture must reproduce the same disease in animals;(3) the agent must again be present in the experimental animal: and (4) apure culture must again be obtained.lag phase延迟期The early phase of population growth during which no signs ofgrowth occur.L form 缺壁细菌 L-phase variants; wall-less forms of some bacteria that are induced by drugs or chemicals. These forms can be involved in infections. lipopolysaceharide 脂多糖 A molecular complex of lipid and carbohydrate found in the bacterial cell wall. The lipopolysaccharide (LPS) of gram-negative bacteria is an endotoxin with generalized pathologic effects such as fever. log phase指数期Maximum rate of cell division during which growth is geometricin its rate of increase. Also called exponential growth phase.Meiosis 减数分裂 The type of cell division necessary for producing gametes in diploid organisms. Two nuclear divisions in rapid succession produce four gametocytes, each containing a haploid number of chromosomes.minimum inhibitory concentration (MIC) 最低抑菌浓度The smallest concentration of drug needed to visibly control microbial growth.minimum temperature 最低温度 The lowest temperature at which an organism will grow.missense mutation错义突变 A mutation in which a change in the DNA sequence results in a different amino acid being incorporated into a protein, with varying results.mitosis 有丝分裂Somatic cell division that preserves the somatic chromosome number.mycelium 菌丝菌丝体The filamentous mass that makes up a mold. Composed of hyphae.Mycorrhizae 菌根Various species of fungi adapted in an intimate, mutualistic relationship to plant roots.nitrification硝化作用Phase of the nitrogen cycle in which ammonium is oxidized. nitrogen fixation固氮作用 A process occurring in certain bacteria in which atmospheric Ngas is converted to a form (NH4) usable by plants.2nonsense mutation 无义突变A mutation that changes an amino acid-producing codon into a stop codon, leading to premature termination of a protein. nucleus 细胞核The central core of an atom, composed of protons and neutrons. obligate专性Without alternative; restricted to a particular characteristic.Example: An obligate parasite survives and grows only in a host; an obligate aerobe must have oxygen to grow; an obligate anaerobe is destroyed by oxygen. optimum temperature最适温度The temperature at which a species shows the most rapid growth rate.parasite 寄生虫An organism that lives on or within another organism (the host), from which it obtains nutrients and enjoys protection. The parasite produces some degree of harm in the host.passive transport 被动运输Nutrient transport method that follows basic physical laws and does not require direct energy input from the cell. pasteurization 巴斯消毒法Heat treatment of perishable fluids such as milk, fruit juices, or wine to destroy heat-sensitive vegetative cells, followed by rapid chilling to inhibit growth of survivors and germination of spores. It prevents infection and spoilage.pathogen 病原体Any agent, usually a virus, bacterium, fungus, protozoan, or helminth, that causes disease.phage 噬菌体A bacteriophage; a virus that specifically parasitizes bacteria. phenotype表型The observable characteristics of an organism produced by the interaction between its genetic potential (genotype) and the environment. photoautotroph 光合自养生物An organism that utilizes light for its energy and carbon dioxide chiefly for its carbon needs.pill Small, stiff filamentous appendages in gram-negative bacteria that functionin DNA exchange during bacterial conjugation.plasmids质粒 Extrachromosomal genetic units characterized by several features.A plasmid is a double-stranded DNA that is smaller than and replicatesindependently of the cell chromosome; it bears genes that are not essential for cell growth; it can bear genes that code for adaptive traits; and it is transmissible to other bacteria.polysaccharide多糖 A carbohydrate that can be hydrolyzed into a number of monosaccharides. Examples: cellulose, starch, glycogen.prion朊病毒A concocted word to denote “proteinaceous infectious agent”; a cytopathic protein associated with the slow-virus spongiform encephalopathies of humans and animals.prophage 原噬菌体 A lysogenized bacteriophage; a phage that is latently incorporated into the host chromosome instead of undergoing viral replication and lysis.protoplast原生质体A bacterial cell whose cell wall is completely lacking and that is vulnerable to osmotic lysis.protozoa 原生动物A group of single-celIed, eucaryotic organisms. pseudohypha 假菌丝A chain of easily separated, spherical to sausage-shaped yeast cells partitioned by constrictions rather than by septa.pure culture 纯培养A container growing a single species of microbe whose identity is known.Retrovirus逆转录酶病毒 A group of RNA viruses (including HIV) that have the mechanisms for converting their genorne into a double strand of DNA that can be inserted on a host’s chromosome.reverse transcriptase逆转录酶The enzyme possessed by retrovimses that carries out the reversion of RNA to DNA a form of reverse transcription. rhizobia 根瘤菌Bacteria that live in plant roots and supply supplemental nitrogen that boosts plant growth.rhizosphere 根际The zone of soil, complete with microbial inhabitants, in the immediate vicinity of plant roots.rickettsias 立克次体Medically important family of bacteria, commonly carried by ticks, lice, and fleas. Significant cause of important emerging diseases. root nodules 根瘤Small growths on the roots of legume plants that arise froma symbiotic association between the plant tissues and bacteria (Rhizobia).This association allows fixation of nitrogen gas from the air into a usable nitrogen source for the plant.silent mutation同义突变 A mutation that, because of tire degeneracy of the genetic code, results in a nucleotide change in both the DNA and mRNA but not the resultant amino acid and thus, not the protein.spore孢子 A differentiated, specialized cell form that can be used for dissemination, for adverse conditions, and/or for are usually unicellular and may develop into gametes or vegetative organisms.stationary growth phase 稳定期Survival mode in which cells either stop growing or grow very slowly.sterilization 灭菌Any process that completely removes or destroys all viablemicroorganisms, including viruses, from an object or habitat. Material so treated is sterile.strict, or obligate anaerobe严格厌氧微生物An organism which does not use oxygen gas in metabolism and cannot survive in oxygen’s presence.symbiosis共生An intimate association between individuals from two species; used as a synonym for mutualism.synergism协同作用The coordinated or correlated action by two or more drugs or microbes that results in a heightened response or greater activity. temperate phage 温和噬菌体A bacteriophage that enters into a less virulent state by becoming incorporated into the host genome as a prophage instead of in the vegetative or lytic form that eventually destroys the cell.template 模板The strand in a double stranded DNA molecule which is used as a model to synthesize a complementary strand of DNA or RNA during replication or transcription.thermal death point致死温度The lowest temperature that achieves sterilization in a given quantity of broth culture upon a 10-minute exposure. Examples: 55℃for Escherichia coli, 60℃ for Mycobacterium tuberculosis, and 120℃ for spores.thermal death time热致死时间The least time required to kill all cells of a culture at a specified temperature.thermophile 嗜热生物A microorganism that thrives at a temperature of 50℃ or higher.transcription转录mRNA synthesis; the process by which a strand of RNA is produced against a DNA template.transduction转导The transfer of genetic material from one bacterium to another by means of a bacteriophage vector.transformation转化In microbial genetics, the transfer of genetic material contained in “naked” DNA fragments from a donor cell to a competent recipient cell.transposon转位子A DNA segment with an insertion sequence at each end, enabling it to migrate to another plasmid, to the bacterial chromosome, or to a bacteriophage.Vibrio弧菌A curved, rod-shaped bacterial cell.virulence 毒性In infection, the relative capacity of a pathogen to invade and harm host cells.zygospore 接合孢子A thick-walled sexual spore produced by the zygomycete fungi.It develops from the union of two hyphae, each bearing nuclei of opposite mating types.。