Isolation and identification as well as screening of excellent lactic acid bacteria from natural fermented milk in Inner Mongolia
Fresh milk and fermented milk are one of the main sources of nutrition in the daily diet of herders,which contains rich lactic acid bacteria.In order to understand the community structure of lactic acid bacteria in different milk sources and obtain valuable lac-tic acid bacteria strains,411 strains,including 10 genus and 21 species,were isolated from 21 samples in Inner Mongolia pastoral area by pure culture technique.The number of Lactococcus lactis isolates was the most,followed by Lactobacillus helveticus and Lactobacillus ke-fir anofaciens.The analysis of diversity showed that the community structure of different milk sources was very different,the diversity of koumiss was the most abundant,and L.kefiranofaciens was one of its dominant strains.According to the tolerance characteristics of low pH and low alcohol content of koumiss,4 strains from 93 strains of L.kefiranofaciens were selected with high tolerance to pH 3.0 and 6％ethanol.Their tolerance in artificial gastric fluid,intestinal fluid and different ethanol concentrations,as well as their inhibitory ability to 3 common pathogens in food were further analyzed.Finally,two strains of L.kefiranofaciens were selected,respectively:IMAU12331 and IMAU12208.Both strains had excellent tolerance and antibacterial properties,and could be used as potential probiotics with high potential application value.
lactic acid bacteriaisolation and identificationstrain screeningtolerancebacteriostatic property
万方数据
维普
