Investigation on High Cell Density Cultivation of Lactobacillus brevis Specific for Vegetable Fermentation

Abstract:

In order to achieve the high cell density culture of Lactobacillus brevis H3，the effects of medium formula，culture conditions，neutralizers and feed batch methods on viable cell counts have been investigated. Suitable medium formulation are：25 g/L glucose，15 g/L yeast，1.53 g/L citric acid，18.58 g/L sodium citrate，20 mg/L VB6，0.58 g/L MgSO4·7H2O，0.25 g/L MnSO4·5H2O，1 g/L Tween-80. Optimal culture conditions are temperature 30 ℃，cultural fluid amount 40mL，pH 6.3～5.8，using 20% sodium citrate as neutralizer. Appropriate feeding culture method is 4% carbon and nitrogen sources （C/N ratio 5：3），which was added after 10 and 20 h，respectively. When fermented at the optimal culture conditions，the number of the bacteria cells was up to 1.27×1010 CFU/mL，which was 7.5 times as high as that when it was not optimized.