Optimization Of Enrichment Medium And High Cell Density Cultivation Of Pediococcus Acidilactici IMAU95219

In this study,Pediococcus acidilactici IMAU95219 with excellent fermentation characteristics and high temperature resistance was taken as the research object.The single-facto test,mixing experiments and response surface analysis were used to study its bacteriogenic medium formulation,static culture conditions and high cell density fermentation.The purpose is to increase the number of viablecellsof P.acidilactici IMAU95219 in the high-density fermentation broth,and provide a theoretical basis for the industrial production of P.acidilactici IMAU95219 microecological preparation.The experimental results are as follows:(1)Based on MRS medium,the factors including carbon source,nitrogen source,total amount and proportion of carbon and nitrogen,buffer salts,trace elements and growth factors were tested and the optimum culture medium was obtained.The optimum culture medium was as follows:glucose 35.16 g/L,yeast extract 48.33 g/L,yeast peptone 16.11 g/L,K2HPO4 5.16 g/L,C2H3Na02 12.88 g/L,C6HSNa3O7 5.16 g/L,MgSO4d(?)7H201.20 g/L,MnSO4(?)5H2O 0.01 g/L,VB2 0.50 g/L,Tween-80 1.00 g/L.(2)The optimum static culture conditions of Pediococcus acidilactici IMAU95219 were as follows:initial pH value:6.5,the inoculation amount:5%,the culture temperature:30℃.After 24 hours of aerobic culture,the number of viable bacteria in the fermentation broth can reach(6.93±0.29)X 109 CFU/mL,which increased by 1.69 times compared with that before optimization.(3)The optimal high-density fermentation process was obtained after a high-density fermentation test was conducted using a 5 L fermentation tank:the neutralizing agent:25%ammonia water and constant pH value:6.5.The growth rate and viable cell density of the bacteria significantly increased.The number of viable bacteria in the fermentation broth can reach(1.01±0.07)×1010 CFU/mL.