低温对保加利亚乳杆菌CspA基因表达影响的研究

摘要

Through the method of low temperature treatment on Lactobacillus bulgaricus,the expression of cold shock protein CspA,freeze-thawing survival rate and freeze-drying survival rate had been investigated.Induced Lactobacillus bulgaricus with different temperature and time conditions,CspA mRNA expression before and af-ter induction was detected by the method of quantitative PCR.Through the method of repeated freeze-thawing treatment,freeze-thawing survival rate was detected by viable count before and after low temperature treatment. Through the method of freeze-drying,the freeze-drying survival rate was detected before and after low tempera-ture treatment.The result showed that the expression of CspA was significantly increased by the treatment of low temperature,with the treatment of 20℃in 4 h,the expression of CspA was reached the highest,and the freeze-thawing or freeze-drying survival rate was increased significantly. CspA can improve the freeze-thawing or freeze-drying survival rate of Lactobacillus bulgaricus.%通过对保加利亚乳杆菌进行低温诱导处理,考察其冷休克蛋白A(cold shock proteins A,CspA)的表达,以及菌体的冻融存活率和冻干存活率.在不同温度、不同时间条件下诱导处理保加利亚乳杆菌,利用荧光定量聚合酶链式反应(polymerase chain reaction,PCR)的方法检测诱导前后CspA的mRNA表达量;通过反复冻融,利用活菌计数法检测诱导前后菌体的冻融存活率;通过冻干试验,检测其诱导前后菌体的冻干存活率.结果表明:低温处理可使CspA的表达量明显提高,且在20℃处理4 h后CspA的mRNA表达量最高,并且菌体冻融存活率和冻干存活率显著提高.CspA可以提高保加利亚乳杆菌的冻融存活率和冻干存活率.