Study On Biological Characteristic And Functionality Of The Lactic Acid Bacteria Separated From Acid-Gruel In Inner Mongolia

13 Lactic acid Bacterias were separated from traditional fermentation food acid-gruel in Inner Mongolia and identified. They were all Lactobacillus. And NSZL-2 and NSZL-12 belong to Lactobacillus rhamnosus, NSZL-11 belongs to Lactobacillus casei.The characteristics of these strains, including acid resistance, bile tolerance, cholate tolerance, bacteriostasis activities and cholesterol-reducing ability were determined through vitro test. The result showed that the survival rate of some strains, such as NSZL-2, NSZL-3, NSZL-5, NSZL-8, NSZL-10, NSZL-11 and NSZL-12, could be exceeding 50% at pH3.0. And decomposition rate of cholesterol of some strains, NSZL-1, NSZL-2, NSZL-4, NSZL-7, NSZL-10, NSZL-11 and NSZL-12, can be up to 50%. The metabolites of the 13 lactobacillus could great inhibit the growing of Salmonella typhi, Escherichia coli, Bacillus Subtilis and had the poor inhibitory action on Staphylococcus Aureus. In a word, lactobacillus NSZL-2, NSZL-11 and NSZL-12 were of good biological characteristics and may be the potential functionality strains.Moreover, the potential functionality strains were studied deeply on the fermentation characteristics, acid producing ability, the change of viable count, syneresis characteristics, the change of OD and the change of viscosity in fermentation milk. After being inoculated with these lactobacillus, the fermentation milk could curded in 12h,and the acidity closed to requirements of industral production at this moment. During the cold storage, there were 107cfu/mL living bacterias in fermentation milk after 28d, and a little whey precipitation appeared.