Synthesis of nucleotide sugars and α-galacto-oligosaccharides by recombinant Escherichia coli cells with trehalose substrate

Useful nucleoside diphosphate (NDP)-sugars and α-galacto-oligosaccharides were synthesized by recombinant Escherichia coli whole cells and compared to those produced by enzyme-coupling. Production yields of NDP-glucoses (Glcs) by whole cells harboring trehalose synthase (TS) were 60% for ADP-Glc, 82% for GDP-Glc, and 27% for UDP-Glc, based on NDP used. Yield of UDP-galactose (Gal) by the whole-cell harboring a UDP-Gal 4-epimerase (pGALE) was 26% of the quantity of UDP-Glc. α-Galacto-oligosaccharides, α-Gal epitope (Galα-3Galβ-4Glu) and globotriose (Galα-4Galβ-4Glu), were produced by the combination of three recombinant whole cells harboring TS, pGALE, and α-galactosyltransferase, with production yields of 48% and 54%, based on UDP, respectively. Production yields of NDP-sugars and α-galacto-oligosaccharides by recombinant whole-cell reactions were approximately 1.5 times greater than those of enzyme-coupled reactions. These results suggest that a recombinant whole-cell system using cells harboring TS with trehalose as a substrate may be used as an alternative and practical method for the production of NDP-sugars and α-galacto-oligosaccharides.