Synthesis of Chitin Oligosaccharides Using Dried Stenotrophomonas maltophilia Cells Containing a Transglycosylation Reaction-Catalyzing β-N-Acetylhexosaminidase as a Whole-Cell Catalyst.

Bacterial strain NYT501, which we previously isolated from soil, was identified as Stenotrophomonas maltophilia, and it was confirmed that this strain produces an intracellular β-N-acetylhexosaminidase exhibiting transglycosylation activity. Several properties of this enzyme were characterized using a partially purified enzyme preparation. Using N,N'-diacetylchitobiose (GlcNAc)2 and N,N',N″-triacetylchitotriose (GlcNAc)3 as substrates and dried cells of this bacterium as a whole-cell catalyst, chitin oligosaccharides of higher degrees of polymerization were synthesized. (GlcNAc)3 was generated from (GlcNAc)2 as the major transglycosylation product, and a certain amount of purified sample of the trisaccharide was obtained. By contrast, in the case of the reaction using (GlcNAc)3 as a substrate, the yield of higher-degree polymerization oligosaccharides was comparatively low.