Optimization and evaluation of process condition of high density culture of Lactobacillus acidophilus

Objective To study the culture conditions of Lactobacillus acidophilus,and to develop a fermentation with high bacterial activity,big density,simple operation,easy for production application,and to clarify the production and application of lactic acid bacteria.Methods Lactobacillus acidophilus strain of Chinese strains were selected;according to the proportion of different medium components,experimental group and control group were set up;the culture conditions and formula of MRS liquid culture medium were optimized,and the A650 value of bacteria liquid and the number of live bacteria were detected by UV spectrophotometer,and the optimal process was screened out.Results Through screening the optimum culture conditions of Lactobacillus acidophilus were determined;the inoculation quantity was 1%,initial pH value was 6.2,the constant temperature was 37 ℃ and the culture time was 23h..The optimum culture medium formula was peptone 3.5%,yeast extract 0.5%,2% glucose,0.2%citric acid ammonium,0.088% sodium hydrogen phosphate two,0.6% sodium acetate,0.025% manganese sulfate,magnesium sulfate 0.06%,1% nutrition factor,0.1% Twain 80;the number of bacteria was up to 1.43× 1011 cfu·mL-1 cultured with the optimal culture process;compared with the traditional training scheme,the number of bacteria species was increased about 1×1011 cfu·mL-1,and the process was simple and easy.Conclusion Through the optimization of culture conditions and culture medium of Lactobacillus acidophilus,the best culture conditions of Lactobacillus acidophilus are obtained,the high density cultivation of strain is conduted,and a theoretical foundation for preparation and application of lactic acid bacteria is laid.