Glycosyltransferases bacterial

In summary, different strategies for the combinatorial biosynthesis of oHgosaccharides have been established successfully. However, some systems are Hmited mostly to bacterial glycosyltransferases because of their better expression in E. coli. The yeast systems seem to be better suited for expression of mammahan glycosyltransferases however, it remains to be demonstrated if they can be also utilized as living factories for the production of oligosaccharides. 

Scheme 28 The production of oligosaccharides Gbs, Gb4, LNT-2, LNnT, and LSTd through successive reactions using recombinant bacterial glycosyltransferases.

Examples of bacterial glycosyltransferases whose activities were detected in E. coli are shown in the Table. The genes of galactosyltransferase were cloned from Neisseria gonorrhoeae (6), N. meningitidis (7,8), Helicobacter pylori... 

Using bacterial glycosyltransferases which can be easily obtained through the expression in E. colU large-scale synthesis of oligosaccharides with cofactor recycling can be carried out. However it might have limitation because these methods require purified enzymes such as pyruvate kinase and expensive substrates such as PEP. 

A system of oligosaccharide production by the combination of a bacterial glycosyltransferase and sugar nucleotide production was proposed on the basis that sugar nucleotides could be synthesized by bacterial coupling. 

By coupling of the sugar nucleotides production system with bacterial glycosyltransferase, an oligosaccharide production system that could be applied to the industrial manufacture was successfully constructed. Oligosaccharides production by bacterial coupling is suitable for large-scale synthesis. 

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