N-Glucosylation in Corynebacterium glutamicum with YdhE from Bacillus lichenformis

Corynebacterium glutamicum is traditionally known as a food-grade microorganism due to its high ability to produce amino acids and its endotoxin-free recombinant protein expression factory. In recent years, studies to improve the activities of useful therapeutics and pharmaceutical compounds have led to the engineering of the therapeutically advantageous C. glutamicum cell factory system. One of the well-studied ways to improve the activities of useful compounds is glucosylation with glycosyltransferases. In this study, we successfully and efficiently glycosylated therapeutic butyl-4-aminobenzoate and other N-linked compounds in C. glutamicum using a promiscuous YdhE, which is a glycosyltransferase from Bacillus lichenformis. For efficient glucosylation, components, such as promoter, codons sequence, expression temperatures, and substrate and glucose concentrations were optimized. With glucose as the sole carbon source, we achieved a conversion rate of almost 96% of the glycosylated products in the culture medium. The glycosylated product of high concentration was successfully purified by a simple purification method, and subjected to further analysis. This is a report of the in vivo cultivation and glucosylation of N-linked compounds in C. glutamicum.