DVS乳酸菌种菌株保存过程中遗传稳定性分析

Genetic stability assessments of lactic acid bacteria separated from DVS during storage

对从某直投式酸奶发酵剂中分离出的乳酸菌菌株在保存过程中的遗传稳定性进行了分析。观察各种保存情况下各菌株复壮时的形态,用RAPD方法分析不同保存方法保存不同时间的乳酸菌基因组的变化,并用SDS-PAGE对比不同保存方法保存不同时间乳酸菌的全细胞蛋白质表达的差异。结果表明,乳球菌在4℃保存和-80℃保存过程中基因组有变化,蛋白质表达无变化;冻干保存前后基因组和蛋白质表达均无变化。杆菌1在4℃保存过程中基因组基本无变化,蛋白质表达有变化;-80℃保存过程中基因组有变化,蛋白质表达无明显变化;冻干保存前后基因组和蛋白质表达均无变化。杆菌2在4℃保存过程中基因组和蛋白质表达均有变化;-80℃保存过程中基因组和蛋白质表达均有变化;冻干前后基因组和蛋白质表达均无变化。采用RAPD方法可以有效地对乳酸菌种菌株保存过程中的遗传稳定性进行分析。

Purpose: To analyse the genetic stability of lactic acid bacteria separated from DVS during storage. Methods: Evaluate the genome change of the different samples from different period during 4 storage,-80 storage and lyophilization using RAPD. SDS:-PAGE was used to evaluate the change of protein expressing. Results: The genome and protein expressing of Streptococcus thermophillus didn't a good stability; Both Lactobacillus 1 and Lactobacillus 2 didn't hold a good genetic stability during 4 and-80 storage. But they showed a good genetic stability when stored by lyophilization. Suggests: The RAPD technique therefore appears to be a fast, simple and efficient method for evaluating genetic stability of lactic acid bacteria separated from DVS.