Batch and Continuous Cultivation of Lactobacillus crispatus KLB46 on MRS broth

초록

For probiotic use in the human vagina as a barrier to infections and as an alternative to long-term use of antibiotics, lactobacilli were isolated from Korean women and selected by antimicrobial activity test. In this study, we cultivated Lactobacillus crispatus KLB46 that showed strong antimicrobial activity to investigate the effects of various cultivation conditions which include changes in the concentrations of major carbon and nitrogen sources in the medium, pH and temperature of culture broth on the viable cell production. Cells were grown in batch and continuous culture modes to obtain maximum number of viable cell. From test tube culture experiment it was found that the viable cell count of Lactobacillus crispatus KLB46 did not increase proportionally with the increase in glucose or yeast extract concentration and the maximum viable cell count was obtained at 37℃ and initial medium pH 5.5. In batch cultivation, the maximum specific growth rate of L. crispatus KLB46 was 0.63 hr1 and the highest viable cell count (1.9 × 109 CFU/㎖) was obtained at pH 5.5. L. crispatus KLB46 did not grow well at pH 3.5 and 7.5, however, high viable cell count was obtained at broad pH rage (between 4.5 and 6.5). In continuous cultivation, the highest viable cell count (1.53 × 109 CFU/㎖) was obtained at a dilution rate 0.32 hr1, however, the maximum productivity of viable cell was obtained at a dilution rate 0.52 hr1 and was 7.33 × 1011 CFU/L/h that is 4.76 times higher than that obtained from batch culture.