The Optimization About Medium And Cultivating Condition Of Lactobacillus Reuteri IMAU10240

L. reuteri IMAU10240 is a potential probiotic bacteria. In order to realize industrialization application, The medium and culture conditions were studied by single factor test, the orthogonal test and response surface analysis on the basis of MRS. The main conclusions are presented as follows:1.all ingredients and quantity of static medium:22.67 g/L maltose,22.67g/L sucrose, 7.62 g/L stachyose,13.25 g/L soy peptone,8.84 g/L yeast extract powder,13.25 g/L yeast peptone,19.85 g/L Na2HPO4,2.58 g/L citric acid,0.4 g/L MgSO4·7H2O,0.12 g/L MnSO4·5H2O,2.76 g/L glycerol,l g/L Tween-80,0.5g/L L-cysteine hydrochloride.2.Optimal culture condition was:initial pH 6.5, temperature 37℃,inoculation amount 2%. The optimum medium was further used for high cell density culture in 5L fermentor. The result showed that the fermentation time (7h) was obvious shorter than the static culture. The increment of the viable counts can rise by 108% to 5.40×109CFU/mL compared with the static culture (2.59×109CFU/mL)3.According to experimental phenomenon and results,the optimal quantity of carbon and pH of high cell density fermentation were optimized through single factor test. Result showed the optimum fermented medium was:37.5g/L maltose,37.5g/L sucrose,25g/L stachyose,13.25g/L soy peptone,8.84g/L yeast extract powder,13.25g/L yeast peptone, 19.85g/L Na2HPO4,2.58g/Lcitric acid,0.4g/L MgSO4·7H2O,0.12g/L MnSO4·5H2O,2.76g/L glycerol,1g/L Tween-80,0.5g/L L-cysteine hydrochloride. The Optimal pH in high cell density fermentation is 5.5.The mentioned fermented medium and conditions were used high cell density culture in 5 L fermentor. The result showed that the viable counts can reach as much as 7.25×109CFU/mL.In contrast with the static culture (2.59×109CFU/mL),The increment of viable counts is obvious.