Microbial production of steviol glycosides

A method for producing Rebaudioside M (RebM), comprising:

• providing an E. coli host cell expressing recombinant uridine diphosphate-dependent glycosyl transferase (UGT) enzymes catalyzing the following glycosyltransferase reactions on steviol or steviol glycoside substrate:
• 13-O glycosylation, 19-O glycosylation, 1-2′ glycosylation at C-19 and C-13, and 1-3′ glycosylation at C-19 and C-13;
• the E. coli host having one or more genetic modifications increasing the production of UDP-glucose;
• culturing the E. coli host cell in a culture medium under conditions suitable for producing RebM, wherein the host cell transports RebM into the culture medium;
• and
• recovering RebM from the culture medium.