The Domestication, Application And Properties Of The Osmophilic Lactic Acid Bacteria

The lactic acid bacteria SQ51, SQ63, Y4and Y5were domesticated by sugar resistance, salt resistance and ethanol high osmotic pressure resistance, then tested on its acid resistance, bile salt resistance, artificial gastrointestinal liquid resistance and degrade cholesterol. The strains which were osmophilic and have better physicochemical properties were selected to do application test on a commercially available high-sugar fermentation products named "Yang Mingyuan". Results showed that the highest critical concentration on the sugar, salt and ethanol resistance of4tested lactic acid bacteria can reached to42%,12%and26%, respectively. By the tests of the acid resistance, bile salt resistance artificial gastrointestinal liquid resistance and degrade cholesterol, the survival rate of SQ63can reached98.15%when cultivated in the acidity of pH3.0for3h, and can reached5.73%when cultivated in the bile concentration of0.3%for6h. In the pH value of8.0artificial intestinal liquid it also can maintain a high survival rate, and the cholesterol degrading ability can reached45.1%, which shows that the SQ63have better physicochemical properties. The viable count of SQ63was gradually decreased when the concentration of Yang Mingyuan increased. And the SQ63would stop growing when the sugar concentration of Yang Mingyuan reached40.95%. The strain SQ63was Lactobacillus by16S rDNA sequence analysis (99.6%similarity).