Efficient Production of MK-7 by Metabolic Engineering in Bacillus subtilis

Abstract:

Menaquinone-7 (MK-7) has a promising application prospect in the fields of health food and pharmaceutical manufacturing as an important vitamin of the K family. In this work, the yield of MK-7 fermentation was improved by using Bacillus subtilis 168 as the starting strain, knocking out the genes from metabolic branch pathways, screening and optimizing the mutant of speed-limited gene menA of the MK-7 synthesis pathway, and enhancing the expression of several MK-7 biosynthesis pathway genes through an artificial operon. Finally, a high-yield strain MK7-13 was developed with the yield of （73.73±1.86） mg/L, which was 9.71 times higher than that of the original strain. In summary, a high-yield MK-7 strain was successfully constructed by a combinatorial metabolic engineering strategy, which laid a foundation for the subsequent industrial production of MK-7 by microbial fermentation.