氧化葡萄糖酸杆菌中硫辛酸合成模块对维生素C一步混菌发酵的影响

Biosynthesis of α-lipoic acid in Gluconobacter oxydans increases the production of vitamin C by one-step fermentation

摘要:

在由氧化葡萄糖酸杆菌和普通生酮古龙酸杆菌构建的维生素C两菌一步发酵体系中，为了强化氧化葡萄糖酸杆菌对普通生酮古龙酸杆菌生长和产酸的促进作用，文中在氧化葡萄糖酸杆菌中构建硫辛酸合成功能模块。由含硫辛酸功能模块的氧化葡萄糖酸杆菌和普通生酮古龙酸杆菌组成的两菌一步体系，能减轻普通生酮古龙酸杆菌单菌培养时的生长抑制，强化两菌的互作关系，使维生素C前体（2-酮基-L-古龙酸，2-KGA）的产量提高到73.34 g/L（对照组为59.09 g/L），醇酸转化率提高到86.0%。研究结果为进一步优化维生素C两菌一步发酵体系提供了新思路。

关键词:一步发酵，氧化葡萄糖酸杆菌，普通生酮古龙酸杆菌，硫辛酸

Abstract:

In a one-step fermentation system of vitamin C production with Gluconobacter oxydans and Ketogulonicigenium vulgare, a functional module of α-lipoic acid biosynthesis was constructed in G. oxydans. The engineered G. oxydans was co-cultured with K. vulgare to enhance the growth and 2-keto-L-gulonic acid (2-KGA) production of K. vulgare. This one-step fermentation system alleviated the growth inhibition during the mono-culture of K. vulgare and strengthened the interaction between the two bacteria. Moreover, the yield of vitamin C precursor (2-KGA) increased to 73.34 g/L (the control group was 59.09 g/L), and the conversion of D-sorbitol to 2-KGA increased to 86.0%. This study provides a new idea for further optimizing the one-step fermentation system of vitamin C production.

Key words:one-step fermentation, Gluconobacter oxydans, Ketogulonicigenium vulgare, α-lipoic acid