(完整版)三角褐指藻户外高密度培养技术研究毕业论文

本科毕业设计（论文）题目：三角褐指藻户外高密度培养技术研究学院轻工与食品学院专业食品科学与工程（糖工程）学生姓名魏峰指导教师魏东教授提交日期2013年06月03日摘要三角褐指藻（Phaeodactytuum tricornutunm）是一种常用的海水经济硅藻，生长迅速，易于培养，富含丰富的多不饱和脂肪酸，特别是二十碳五烯酸（C20:5，EPA），是水产动物养殖的优质饵料。

目前，三角褐指藻的户外高密度培养技术仍处于研发阶段。

为探究不同条件（环境条件和营养盐）对三角褐指藻生长以及其脂肪酸组成和含量的影响，本研究用单一变量法分别对其培养条件进行对比优化实验。

主要结果如下：（1）选用不同盐度的培养基对三角褐指藻进行户外高密度培养，盐度设定为3个梯度，20‰、25‰、30‰。

结果表明，在盐度为20‰条件下，三角褐指藻的生长状况要优于其他两种盐度，其OD值最高为0.998、细胞密度最高为6.0⨯106个/mL、细胞干重最高为177.78mg/L。

对脂肪酸的测定结果表明，25‰盐度下三角褐指藻细胞的脂肪酸含量最高（124.95mg/g），20‰盐度与25‰盐度基本相同（123.12mg/g），而30‰盐度最低（105.67mg/g）。

（2）在20‰盐度下，通入CO2控制培养基的不同pH值，对三角褐指藻进行户外高密度培养。

pH值设定为3个梯度，7.5、8.0、8.5。

结果表明，控制pH8.0，三角褐指藻的生长状况要远好于其他两种pH值，其OD 值最高为 1.045、细胞密度最高为 5.8⨯106个/mL、细胞干重最高为166.39mg/L。

对脂肪酸的测定结果表明，pH值为8.5时三角褐指藻细胞的脂肪酸含量最高（145.91mg/g），pH值为8.0的稍低（134.92mg/g），pH 值7.5的脂肪酸含量最低（109.76mg/g）。

（3）在20‰盐度、pH 8.0条件下，分别选用碳酸氢铵和尿素作为氮源对三角褐指藻进行户外高密度培养。

结果表明，分别使用碳铵和尿素，三角褐指藻的生长状况基本相同，其最终OD值分别为0.689和0.716，细胞密度分别为3.9⨯106个/mL和4.0⨯106个/mL，细胞干重分别为136.11mg/L 和146.11mg/L。

但通过对脂肪酸的测定，结果表明当使用碳铵作为氮源时三角褐指藻细胞的脂肪酸含量最高（169.72mg/g），尿素作为氮源时脂肪酸含量则相对较低（109.76mg/g）。

（4）在20‰盐度，pH8.0，碳铵作为氮源的条件下，当培养基中氮耗尽时，通过一个昼夜24小时对三角褐指藻的取样研究，结果表明，在上午10点钟时，三角褐指藻中所积累的脂肪酸含量最高（136.15mg/g），而在其他时间段，脂肪酸的含量则相对较低。

（5）在20‰盐度，pH8.0，碳铵作为氮源的条件下，通过对三角褐指藻的一个生长周期内的氮磷同化规律研究表明，三角褐指藻户外高密度生长过程中，对氮的需求需求量很大，平均每天要消耗10.4mg/L的碳酸氢铵。

而对磷的需求则相对较小，每天平均只消耗0.13mg/L的磷酸二氢钠。

关键词：三角褐指藻；盐度；pH值；氮源；脂肪酸AbstractPhaeodactytuum tricornutunm is a commonly used seawater economic diatoms, rapid growth, easy to culture, rich in polyunsaturated fatty acids, especially eicosapentaenoic acid (C20: 5, EPA), is Aquatic animal breeding quality bait. Currently, Phaeodactylum outdoor high-density culture technology is still in development stage. To explore the different conditions (environmental conditions and nutrients) on the growth of Phaeodactylum and their fatty acid composition and content of, a single variable method used in this study were to compare their culture conditions optimization experiments. The main results are as follows:(1) selection of different salinity media on Phaeodactylum outdoor high-density culture, salinity gradient is set to 3, 20 ‰, 25 ‰, 30 ‰. The results showed that under the conditions of salinity of 20 ‰, Phaeodactylum growth conditions better than the other two salinity, its highest OD value of 0.998, the highest cell density 6.0 106 个/ mL, the highest cell dry weight was 177.78mg / L. The results show that for the determination of fatty acids, 25 ‰ salinity Phaeodactylum cell fatty acid content of the highest (124.95mg / g), 20 ‰ and 25 ‰ salinity salinity is basically the same (123.12mg / g), and 30 ‰ salt lowest (105.67mg / g).(2) at 20 ‰ salinity, leads to CO2 control medium at different pH values of Phaeodactylum outdoor high-density culture. pH gradient value is set to 3, 7.5,8.0,8.5. The results show that the control pH8.0, Phaeodactylum growth conditions far better than the other two pH values, the OD values of up to 1.045, the highest cell density of 5.8 106 个/ mL, cell dry weight up to 166.39mg / L. The measurement results show that the fatty acid, pH value of 8.5 Phaeodactylum highest fatty acid content of the cell (145.91mg / g), pH 8.0 is lower (134.92mg / g), pH of the fatty acid content of 7.5 minimum ( 109.76mg / g).(3) at 20 ‰ salinity, pH 8.0 conditions, were selected ammonium bicarbonate and urea as a nitrogen source for Phaeodactylum outdoor high-density culture. The results show that the use of ammonium bicarbonate and urea, respectively, Phaeodactylum basically the same growth conditions, the final OD values were 0.689 and 0.716, the cell density was 3.9 106 cells / mL and 4.0 106 个/ mL, cell dry weight were 136.11mg / L and 146.11mg / L. But through the fatty acids measured,the results show that when using ammonium bicarbonate as a nitrogen source Phaeodactylum cell fatty acid content of the highest (169.72mg / g), urea as a nitrogen source when the fatty acid content is relatively low (109.76mg / g) .(4) at 20 ‰ salinity, pH8.0, ammonium bicarbonate as a nitrogen source conditions, when the medium is depleted of nitrogen, 24 hours a day through a pair Phaeodactylum sampling, the results showed that in the morning 10 o'clock, Phaeodactylum fatty acid contentof the accumulated maximum (136.15mg / g), while in other time periods, fatty acid content is relatively low.(5) in 20 ‰ salinity, pH8.0, under conditions of ammonium bicarbonate as a nitrogen source, through Phaeodactylum during the growth cycle of a law of assimilation of nitrogen and phosphorus that Phaeodactylum outdoor high-density growth in great demand for nitrogen demand, the average daily consumption of 10.4mg / L of ammonium bicarbonate. The demand for phosphorus is relatively small, the average daily consumption of only 0.13mg / L sodium dihydrogen phosphate. Keyword:Phaeodactytuum tricornutunm; Salinity; pH; Nitrogen; Fatty acid目录摘要........................................................................................................................................ Abstract.................................................................................................................................... 第一章绪论............................................................................................................................1.1国内外微藻及其脂肪酸研究进展 .....................................................................................1.2硅藻及三角褐指藻概述 ..............................................................................................1.3硅藻及三角褐指藻培养技术 ......................................................................................1.4影响硅藻脂肪酸组成和含量的环境因子 ..................................................................1.5本课题的研背景和意义 ..............................................................................................1.6本课题的研究内容.......................................................................................................第二章实验材料与测试方法 .................................................................................................2.1实验材料与仪器...........................................................................................................2.2试验方法.......................................................................................................................2.2.1实验室阶段培养.................................................................................................2.2.2户外培养及采收.................................................................................................2.3分析与测试...................................................................................................................2.3.1细胞密度、OD值和细胞干重 .........................................................................2.3.2培养基中氮、磷含量的测定 (1)2.3.3脂肪酸组成与含量的测定 (1)第三章不同条件对三角褐指藻生长及脂肪酸积累情况探究 (1)3.1盐度 (1)3.1.1实验方法 (1)3.1.2结果分析 (1)3.2 pH值 (1)3.2.1实验方法 (1)3.2.2结果分析 (1)3.3氮源种类 (1)3.3.1实验方法 (1)3.3.2结果分析 (1)第四章昼夜变化对三角褐指藻脂肪酸组成和含量的影响 (2)4.1实验方法 (2)4.2结果分析 (2)第五章户外培养过程中细胞对氮、磷的同化规律研究 (2)5.1实验方法 (2)5.2结果分析 (2)第五章结果与展望 (2)参考文献 (2)致谢 (2)第一章绪论1.1国内外微藻及其脂肪酸研究进展微藻是一类体积小、结构简单、生长繁殖迅速的单细胞藻类。