植物乳杆菌Lp-2的高密度发酵

High Cell Density Culture of Lactobacillus plantarum Lp-2

高密度培养植物乳杆菌是制作其发酵剂的重要环节。首先,研究了不同的溶氧和pH对植物乳杆菌的分批发酵的影响。在分批发酵的基础上,为进一步提高发酵液中的菌体浓度,进行了补料分批发酵实验。最终通过对蔗糖反馈补料发酵试验对比改造获得了pH反馈补料发酵工艺。此发酵补料工艺可以控制蔗糖残糖量始终处于较低的水平,因此获得了最高的菌体产量。菌体干重达到13.56g/L,较分批培养提高90.05%。

High cell density culture of Lactobacillus plantaru is a significant step of the preparation of lactic acid bacteria starter. Firstly, this experiment is designed to analyze the effects of different dissolved oxygen and pH on the batch fermentation of Lactobacillus plantarum. And then,on the base of the batch fermentation, fed-batch fermentation was studied, companied by chemic neutralization in the experiment to achieve the aim of high cell density cultivation. Finally, in the comparison of two kinds of feeding mode for fed-batch operation in 10L fermentor, it was demonstrated that two kinds of feeding mode made cell concentration increase differently, in which pH feedback feeding can control sucrose concentration within a certain lower range, therefore obtaining the maximum cell concentration. With the pH feedback feeding , the dry cell weight was up to 13.56g/L, which increased 90.05% over that of batch culture.