Study On Production Characteristics And Several Enzyme Activities Through The N~+Implanting Into Lactobacillus Bulgarius

Preservation and screening of the three start and three N+mutagenesis Bulgaria lactobacillus strains in a laboratory for research object, this test is to research mutagenic treatment to the impact of the shape of the mutants strains in energy, acid, and viscous characteristics,discusses N+mutagenesis treatment on strains of the application of dairy production in influence.Rresearch mutagenic treatment to β-galactosidase galactosidase, lactate dehydrogenase enzyme and other key enzyme of the influence of the activity, to explore enzymatic basis of the mutant strains produced acid force change. Research mutagenic treatment to the influence of protease actiity, investigate the production of ACE inhibitory peptide activity in the enzymatic basis.1. This trial is to research ACE of inhibitory activity and form, vigor, and production in acid, and viscous of the six strains. The results show that, Before and after the inhibition rate to the strains of the mutation ACE and the density of milk, and production in acid, and viscous etc is great different. Among them, mutant strains of the ACE inhibitory activity was significantly higher than the original strains,mutagenesis of strain vigor,producing acid force shows a negative effect;mutagenesis treatment sticky characteristics of the different strains produced different impact,mutant strain P3production viscous shows positive effect,but mutant strains M2、P6show negative effect.At the same time,P3strain of extracellular polysaccharide is higher than that of the L3strain.2. beta-galactosidase and lactate dehydrogenase are two kinds of key enzymes in Bulgaria lactobacillus metabolic process, this experiment on six strains of the two enzyme activities were measured. The results show that, these two kinds of enzyme activity is in a positive correlation between strains of acidic,that shows negative effects of mutagenesis strains of beta-galactosidase and lactate dehydrogenase activities,its activity were lower than the original strain.3. This test selects cell wall protease partnership (CEP), ammonia peptide enzyme PepN, X-prolyl-dipeptide acyl-aminopeptidase enzyme (PepX) as the research object,employ sonication extraction of crude enzyme determination of the protease activity of each strain to explore the relationship of the various strains of protease activity and ACE inhibitory peptide. The results show that, In the best broken conditions, respectively, L2, M2, L3, P3, L6strains of cell walls protease activity is11.7U、12.4U、20.7U、21.1U、20.2U、23.7U. ammonia peptide enzyme PepN activity is16.6U、20.7U、62.4U、80.3U、48.7U、71.3U. Intracellular peptidase activity is10.8U、11.6U、43.8U、51.1U、15.7U、30.9U.So the protease activity of the six strains were different,among them,PepN activity of each strain is relatively high,PepX followed,CEP activity is minimum,protease activity is higher than the starting strains.Comprehensive protease activity of the six strains,the three protease activities of strains selected in the trial are no obvious relationship with the ACE inhibitory peptides produce.