The protective effect of lactose on the bile salt stress response of Streptococcus thermophilus is strain dependent  

作　　者：Yuqi Pan Peng Yu Yang Jiang Xiaoming Liu Jianxin Zhao Hao Zhang Wei Chen 

机构地区：[1]State Key Laboratory of Food Science and Technology,Jiangnan University,Wuxi,Jiangsu,214122,China [2]School of Food Science and Technology,Jiangnan University,Wuxi,Jiangsu,214122,China [3]International Joint Research Laboratory for Pharmabiotics&Antibiotic Resistance,Jiangnan University,Wuxi,Jiangsu,214122,China [4]Wuxi Translational Medicine Research Center and Jiangsu Translational Medicine Research Institute Wuxi Branch,China [5]National Engineering Research Centre for Functional Food,Wuxi,Jiangsu,214122,China

出　　处：《Food Bioscience》2023年第3期802-808,共7页食品生物科学（英文）

基　　金：supported by the National Natural Science Foundation of China(No.31871829,31820103010,and 32021005);the Collaborative Innovation Centre of Food Safety and Quality Control in Jiangsu Province(Jiangsu,China).

摘　　要：Streptococcus thermophilus is generally considered to be sensitive to bile salt stimulation,and its bile salt tolerance is strain specific.In this study,the viable bacteria count,sugar utilization capacity,β-galactosidase activity,and extracellular polysaccharide synthesis capacity of 5 strains of Streptococcus thermophilus in bile salt with or without(w/o)lactose were measured to explore the protective ability of lactose to the strains.The changes in gene expression in stress and carbohydrate metabolism-related pathways were recorded.The results indicated that the protective effect of lactose on the bile salt stress response of Streptococcus thermophilus is strain dependent.Theβ-galactosidase activity of the strains was correlated with the yield of exopolysaccharides(EPS)significantly,and the strain with a high survival rate(4M6)showed higher lactose utilization,β-galactosidase activity and more EPS production in general.

关 键 词：Streptococcus thermophilus Bile salt Lactose utilization EXOPOLYSACCHARIDES 

分 类 号：TS201.3[轻工技术与工程—食品科学]