毕业论文移动版

摘  要从茶卡湖水中分离纯化得到了三株嗜盐细菌，分别编号为CK1、CK3和CK4（CK表示为茶卡盐湖中的嗜盐细菌）。通过培养观察，发现这些嗜盐细菌菌落特征相似，均不透明，颜色呈乳白色，菌落中间微隆起。革兰氏染色后，通过显微观察，发现CK1、CK3和CK4的菌株形态均为杆状，革兰氏染色均为阳性。采用细菌16S r DNA 基因通过引物对CK1、CK3和CK4进行PCR扩增，扩增后的目的片段经克隆后测序，利用MEGA 4。0软件、ContigExpress软件和Clustal X 1。8 软件对三株嗜盐细菌及其相近物种进行同源性比较和系统发育学的分析，结果表明CK1、CK3和CK4均属于枝芽孢杆菌属（Virgibacillus salarius）。选取嗜盐细菌CK4绘制一步生长曲线，表明CK4在0至36 小时处于平稳期，36至40小时处于对数生长期。用不同浓度的NaCl溶液处理对数生长期的CK4细菌，处理结束后用细胞活性染色试剂碘化丙锭(propidium iodide, PI)进行单染色，再应用流式细胞术(flow cytometry, FCM) 检测CK4细胞的死活比，结果表明NaCl浓度为2。0mol/L 时CK4的死亡细胞最少，由此得出结论CK4最适盐浓度为2。0mol/L。72000

该论文有图7幅，参考文献14篇。

毕业论文关键词：嗜盐细菌  最适盐浓度  流式细胞术 

Study on Salt Tolerance of Halophiles under NaCl Stress

Abstract  Three strains of halophiles were isolated from ChaKa Lake 。Named as CK1,CK3 and CK4,respectively。These strains were rod shape,white,gram positive and opaque as a single cell。The bacterial’s 16S r DNA gene was used to amplify PCR by primer pair,after cloning,the target fragment was cloned and sequenced。Using MEGA  4,ContigExpress and Clustal X 1。8 software to compare the homology with the similar species and analysis the phylogenetic,indicates that CK1,CK3 and CK4 all belong to the Virgibacillus salarius。Select CK4 to draw one-step growth curve。The curve indicates that CK4 is in the stable period from 36 h to 40 h and in the rise phase from 36 h to 40 h。Let the bacteria of CK4 in different concentrations of NaCl solution,when the bacteria were in rise phase。After this step, using Flow Cytometry (FCM) to test the cell’s death ratio。The results showed that when NaCl concentration was 2。0mol/L the cell‘s death rate was lowest,it means that the optimum growth concentration of CK4 is 2。0 mol/L NaCl。

Key Words: halophiles  optimum salt concentration  flow cytometry(FCM) 

目  录

摘要-Ⅰ

Abstract-- --Ⅱ

目录-Ⅲ

图清单-Ⅳ

1 绪论- -1

2 材料与方法 --2

2。1材料-2

2。2方法 3

3 结果与分析--5

3。1分离纯化结果-5

3。2菌落与菌体特征-6

3。3 CK1、CK3和CK4的16S r DNA序列分析与系统发育树的构建 6

3。4嗜盐细菌CK4的生长特性-- -8

4 结论-11

参考文献12

致谢-13

图清单

图序号 图名称 页码

图3-1 培养的嗜盐细菌图片 6

图3-2 革兰氏染色图片

6

图3-3 CK1、CK3和CK4的琼脂糖凝胶电泳图

7

图3-4 CK1、CK3和CK4系统发育树

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图3-5 菌株CK4的一步生长曲线 8

图3-6 不同盐浓度胁迫下，CK4死活细胞对比情况 9-10

图3-7 (责任编辑：qin)