Isolation and identification of a thermophilic bacterium producing N,N'-diacetylchitobiose from chitin.

A thermophilic, A^,A^-diacetyIchitobiose((GlcNAc)2)-producing bacterium, strain X-7u, was isolated from hot spring water and identified as Bacillus licheniformis.WhenX-7u was cultivated in a medium consisting of 2.0% colloidal chitin, 0.05 % yeast extract and inorganic salts at 50°C under shaking, (GlcNAc)2 was accumulated to a concentration of 9.6 g/1 within 5 days.This corresponded to 46 % of the stoichiometric yield of (GlcNAc)2.The strain also produced a small amount of N.N'N"triacetylchitotriose. However,neither /V-acetylglucosamine nor other oligosaccharides were accumulated throughout the culture period.N-Acetylchitooligosaccharides ((GlcNAc)^,