An engineered E.coli strain for the production of glycoglycerolipids

The glycolipid synthase MG517 from Mycoplasma genitalium catalyzes the glucosyl transfer from UDPGlc to diacylglycerol producing glycoglycerolipids (GGL) ( Andrés et al., 2011). The enzyme was functional in E. coli accumulating GGL in the plasma membrane. A metabolic engineering strategy for GGL production was evaluated using this microorganism. To increase the levels of GGL precursors, UDPGlc and diacylglycerol, GalU and PlsC enzymes involved in their biosynthesis were overexpressed. Seven engineered strains were obtained containing different combinations of the mg517 with galU and plsC genes. Diacylglycerol synthesis showed to be limiting and the strain overexpressing MG517 and PlsC achieved the highest GGL yield. The new lipids were mono, di- and triglucosyldiacylglycerol with different acyl combinations in each compound. It indicates that the successive glucosyl transferase activities of MG517 have different acyl chain specificity for the acceptor substrate. GGL represented up to 6 mg per g of dry weight.

► A metabolic engineering strategy in E. coli for glycolipids production is proposed.
► The MG517 glycosyltransferase from Mycoplasma genitalium is functional in E. coli.
► Strains combining mg517, plsC and galU genes are evaluated as glycolipid producers.
► Overproduction of diacylglycerol precursor, but not UDP-glucose, increases glycoglycerolipids productivity.
► The recombinant strains present a lower proportion of phosphatidylethanolamine in the lipid membrane.