Creating a novel and versatile glycosylation platform in E. coli

Glycosyltransferases (GTs) are powerful enzymes for the regioselective glycosylation of various small molecules. Because addition of a sugar residue can greatly alter the solubility, stability or bioactivity, the demand for glycosides as nutraceuticals, therapeutics or cosmetics is steadily rising. However, the use of GTs in biocatalysis is often hampered by the need for activated sugar donors (often UDP-sugars) which are expensive and rarely available in large quantity. An efficient solution is the use of microbial whole-cell systems that overexpress GTs and form their own expensive UDP-sugars from cheap substrates. Unfortunately, these processes are frequently plagued by low production yields and rates or difficulties regarding scale-up. In this study, we present the creation of a novel glycosylation platform in Escherichia coli W through Metabolic Engineering. The resulting strain acts as a versatile host for the selective glycosylation of diverse small molecules such as oligosaccharides, phenylpropanoids, flavonoids or hydroxybenzoic acids, hereby using only sucrose as cheap and sustainable carbon source. By introducing a generic toolbox, these compounds can be efficiently glucosylated, galactosylated or rhamnosylated with up to 100 % conversion. Moreover, by exploiting a unique and novel engineering strategy, production is coupled to growth, yielding an easily scalable glycosylation strain with high specific rates and gram scale production.

Jaar van publicatie:2014