摘要：[目的]从早期牛蒡腌制盐卤中分离纯化出一株嗜盐菌，通过分析16s rRNA基因片段，确定该菌株的分类学地位。利用不同NaCl浓度对嗜盐菌进行胁迫，了解该菌的最适生长盐浓度，分析该菌株的生理和生物学特性。为牛蒡榨菜的腌制提供一些理论依据。[方法] 采用稀释涂布、划线等微生物纯培养方法，从牛蒡腌制初期盐卤中分离纯化出一株中度嗜盐菌，提取嗜盐菌的DNA基因组，利用PCR技术、电泳和胶回收等分子生物学方法获得16s rRNA基因且通过测序和构建分子发育树，对嗜盐菌的分类学地位进行分析。利用分光光度计来测量细菌的最适生长时间。通过流式细胞仪检测，分析不同盐浓度对于嗜盐菌活性的影响。[结果]分离出一株嗜盐菌Y5，Y5与中度嗜盐菌Pontibacillus chungwhensis BH030062(T)的序列同源性为99.72%，在培养21h后OD值出现了最高峰，在氯化钠浓度为1.5-2moL/L时细胞的死亡率最低。[结论] Y5属于中度嗜盐菌（Pontibacillus chungwhensis），最适生长时间为21h，最适盐浓度范围为1.5-2moL/L。50719

该论文有图8幅，表1个，参考论文18篇。

毕业论文关键词：牛蒡  嗜盐菌  16s rRNA  流式细胞术  最适盐浓度

Study of advantage halophilic bacterial community in the initial pickle brine of Arctumlappa L

Abstract

[Objective] One strain of halophilic bacteria was isolated from Arctumlappa L pickle brine. The taxonomic status of the strain was identified based on the analysis of 16S rRNA gene. Use different concentrations of NaCl solution to realizethe optimum salt concentration of bacteria and analyzed physical and biological characteristics of this strain. The results provide some theoretical basis for Arctumlappa L pickle. [Method] Based on the gradient dilution, plate culture, one strain of halophilic bacteria from Arctumlappa L pickle brine was purified. The genomic DNA of bacteria was extracted by genomic DNA extraction kit. Based some methods of molecular identification as PCR, gel electrophoresis and gel recovery obtained the 16S rRNA gene of bacteria. The phylogenetic tree based on the 16S rRNA gene sequences indicated the taxonomic status of three strains of bacteria. Based using spectrophotometer, the optimum growth time of bacteria was measured. Based on the Flow cytometer, the activity of bacteria in different salt concentration was analyzed. [Results] one strain of halophilic bacteria was isolated and numbered it as Y5. Y5 has 99.72% similarity with Pontibacillus chungwhensis BH030062(T).When Y5 grow 21 hours, the OD value appeared a peak and it has the lowest mortality rate at salt concentration range of 1.5-2moL/L. [Conclusion] Y5  belongs  Pontibacillus

chungwhensis. The optimum growth time of Y5 is 21h and the optimum salt concentration range is 1.5-2moL/L.

Key words: Arctumlappa L  16srRNA  halophilic bacteria  Flow cytometerthe optimum salt concentration

目录

摘要 I

Abstract II

目录 III

引言 1

1.实验材料 2

1.1 样品采集 2

1.2 培养基 2

1.3 试剂与器材 2

2.试验方法 2

2.1菌株的培养 2

2.2革兰氏染色及菌体形态观察 3

2.3细菌基因组提取 3

2.4电泳检测细菌DNA基因组 3

2.516S rRNA基因的PCR扩增