The Domination Of Lactococcus Lactis And Preservative For Microbe In Soy Sauce Fermentation Process

The microbe of matured Koji and Soy Sauce Paste were isolated,identified and controlled in this study.A set of microbial identification and control methods were researched in soy sauce brewing process for saving material, improving ammonia nitrogen conversion rate.13 bacterial strains were isolated,identified from two samples.They were 1 of Lactobacillus,3 of Micrococcus,3 of Pseudomonas,1 of Bacillus, 2 of Staphylococcus,1 of Escherichia,1 of Lactococcus,1 of Acinetobacter.A mutant strain was selected for high Nisin producing by Microwave for 30s.and numbered as WZ-4,the titer was improved by 67.14%.The genetic test was stable. In soy sauce fermentation, the growth of bacteria could be controlled by adding 0.4 percent of lactic acid fermented liquid, and the amino nitrogen increased 24.4%.At the same time,the date of minimum durability could maintain 62 d without adding salt at 65℃sterilized 30 min.In soy sauce fermentation,Amino nitrogen was increased 24.7% by adding 0.7% of sodium acetate and 0.4% of lactic acid fermented liquid. Amino nitrogen was increased 27% by adding 0.4% of acetate and 0.4% of lactic acid fermented liquid.The date of minimum durability can maintain 120 d,132 d at warranty test.When adding 0.5% of calcium propionate in Soy sauce fermentation the total bacterial count reduced 91.3%,and amino nitrogen increased 19.3%.The result was the best among the 4 kinds of preservatives.