Study On High Cell Density Culture Of Pediococcus Acidilactici IMAU94388

The optimization of high-density fermentation process is a considerably important condition in the industrialized'preparation of starter cultures.In this paper,a strain of Pediococcus acidilactici IMAU94388 that possess excellent fermentation characteristics was used to study the medium composition,static culture conditions and high cell density fermentation technology,the conclusions were as follows:(1)Based on MRS medium,the single factor screening,compound test and response surface design were used to sift the optimum carbon source,nitrogen source,total amount and proportion of carbon and nitrogen,bullet salts,trace elements and growth factors.The optimum IMAU94388 culture medium were as follows:17.48g/L of glucose,12.45g/L of yeast peptone,37.36 g/L of yeast extract,2.43g/L of sodium citrate,6.08g/L of sodium acetate,2.43g/L of K2HPO4,1.00g/L of MgSO4·7H2O,0.30g/L of Vc,Tween-80 1.00g/L.(2)The optimum static culture conditions of IMAU94388 were as follows:when the incubation temperature was 30?,the initial pH was 6.5 and the inoculation amount was 5%,the viable cell number was((8.91±0.16)×109CFU/mL)can be obtained that was 2.46 times more than that before optimization((3.62 ±0.45)×109CFU/mL).(3)The optimal conditions of high-density fermentation were obtained by using the optimized culture conditions to perform small tests of 5L fermentation.The optimum high-density fermentation condition was as follows:constant pH 5.9,the neutralizer was 25%NH3·H2O.The cell growth rate in the fermentation tank was considerably increased.The number of viable cells was((1.41±0.21)×1010CFU/mL)that was 3.89 times compared with that before high density culture((3.62±0.45)×109CFU/mL).In this research,through the optimization of high-density fermentation process of IMAU94388,the preparation process with viable high bacteria count and low-cost was obtained,which provide the theoretical basis for industrial production and application of IMAU94388.