Engineering Escherichia coli to glycosylate polyphenols

Abstract

A group of exciting molecules for the pharmaceutical and healthcare industry are flavonoids, exerting a wide variety of biological functions. These functions are limited by their toxicity, low water solubility, and bioavailability, which can be relieved through glycosylation. Glycosylation reactions are found throughout nature, performed by glycosyltransferases (EC 2.4.-.-). The natural functions of glycosylations range from protein glycosylation, creation of storage glycosides to detoxi cation mechanisms of small molecules. Previous work by Rabausch et al. [1] identi ed a bacterial, metagenome derived glycosyltransferase, GtfC, able to rhamnosylate various polyphenolic substances in whole-cell biotransformations using Escherichia coli as the host organism. This work significantly contributes to the field of glycobiotechnology by firstly increasing glycosylation capabilities of E. coli K-12, secondly by the development of a modular glycosylation platform and finally by the establishment of a rhamnosyltransferase activity screen.