Study On Characteristics Of Lactic Acid Bacteria Strains Producing β-Glucosidase

The renewable energy, which distributes most widely and has the most content on the earth, has a top yield to more than200billion tons every year. The methods of degrading cellulose mainly include oxidative degradation, mechanical degradation and biological degradation, and biological degradation of cellulose is widely used because of the characteristics of simple operation and low cost. Cellulose causes biological degradation, cellulose is divided into Endoglucanase, Exlglucanase and Bata-glycosidase enzymes. Lactic acid bacteria can be used directly as food-grade microorganisms, and it has probiotic function such as promoting animals’growth, improving food digestibility and biological titer, and improving the body immunity.5strains producing β-glycosidase enzymes were selected from lactic acid bacteria that screened and preserved by department of Food Science Yanbian University.In order to learn more about the express parts of the Bata-glycosidase enzymes which are produced by Lactic acid bacteria, and the highest period of growing enzyme during the process of growth, measuring the changes of the growth curve and nutrient solution pH cultivated for24hours, and the Bata-glycosidase enzymes’largest enzyme activity in each point of the time. The conclusion is that the Bata-glycosidase enzymes in the Lactic acid bacteria are all extracellular enzymes. Plant lactobacillus has the best growth and the production of enzymes achieves to the biggest at12hour. The enzyme activity value is13U·mL-1.In order to learn more about the features of Lactic acid bacteria producing Beta glycosidase enzymes, measuring the most appropriate reaction temperature, reaction pH and the substrate specificity of5strains. The most appropriate reaction temperature of Lactobacillus acidophilus and Pediococcus pentosaceus is30℃, Lactobacillus casei is37℃, and Lactobacillus brevis and Lactobacillus plantarum are51℃. The most appropriate reaction pH of all the strains is5.5. All the strains are specific enzymes with many substrates because they can resolve cellobiose, pNPG, oNPG, lactose, maltose and sucrose into glucose.