大肠杆菌AFP111菌体回收连续转化生产丁二酸

Succinic acid production with Escherichia coli AFP111 recovered from fermentation

摘要:

在利用大肠杆菌AFP111厌氧发酵生产丁二酸过程中，随着产物丁二酸的不断积累，菌体活力和产酸能力逐渐降低，而通过回收菌体在新鲜培养基中重复发酵，可延长厌氧发酵时间，但是丁二酸生产效率较低。为了提高菌体回收丁二酸的转化效率，通过在回收菌体时有氧诱导 3 h，以纯水为培养基，进行丁二酸转化发酵。在连续进行 3 批次的发酵后，丁二酸的总产量和最终收率分别为 56.50 g/L和90%，生产速率达到了 0.81 g/(L·h)，比未诱导情况下的生产速率提高了13%。

Abstract:

During the anaerobic fermentation by Escherichia coli AFP111 for succinic acid production, the viable cell concentration and productivity were decreased with the raising of succinic acid concentration. In order to restore cellular succinic acid productivity and prolong fermentation time, we collected strains and refreshed medium for repetitive succinic acid production. However, productivity is lower than that in the anaerobic fermentation before reusing strains. To enhance the productivity, strains were aerobically cultivated for 3 h in pure water before anaerobic fermentation. The activities of key enzymes were enhanced for better performance in producing succinic acid at anaerobic stage. After three rounds of repetitive fermentations, succinic acid concentration and yield reached to 56.50 g/L and 90% respectively. The succinic acid productivity was 0.81 g/(L·h), which was 13% higher than the repetitive fermentations without aerobic activation of the strains.