Impact of chitin-derived β-N-acetyl-d-glucosaminyl-(1,4)-d-glucosamine on chitinase upregulation in Shewanella baltica.

The first steps in chitin degradation in marine bacteria involve chitinase, which produces N,N'-diacetylchitobiose (GlcNAc)2 from chitin. Moreover, in Vibrio bacteria, chitinase activity is enhanced by heterodisaccharide β-N-acetyl-d-glucosaminyl-(1,4)-d-glucosamine (GlcNAc-GlcN) produced from (GlcNAc)2 by chitin oligosaccharide deacetylase (COD). However, the role of COD in other marine bacteria, such as Shewanella, remains unexplored.

Growth of Bifidobacterium pseudocatenulatum in medium containing N-acetylsucrosamine: enzyme that induces the growth of this bacterium via degradation of this disaccharide.

Bifidobacterium pseudocatenulatum grows well in the early stages of cultivation in medium containing sucrose (Suc), whereas its growth in medium containing the analogue disaccharide N-acetylsucrosamine (SucNAc) tends to exhibit a considerable delay. To elucidate the cause of this phenomenon, we investigated the proliferation pattern of B. pseudocatenulatum in medium containing D-glucose (Glc) and SucNAc and identified the enzyme that degrades this disaccharide.

Enzymatic Synthesis and Structural Confirmation of Novel Oligosaccharide, D-Fructofuranose-linked Chitin Oligosaccharide.

Utilizing transglycosylation reaction catalyzed by β- -acetylhexosaminidase of , β-D-fructofuranosyl-(2↔1)-α- , ´diacetylchitobioside (GlcNAc -Fru) was synthesized from -acetylsucrosamine and , ´-diacetylchitobiose (GlcNAc ), and β-D-fructofuranosyl-(2↔1)-α- , ´, ´´-triacetylchitotrioside (GlcNAc -Fru) was synthesized from GlcNAc -Fru and GlcNAc . Through purification by charcoal column chromatography, pure GlcNAc -Fru and GlcNAc -Fru were obtained in molar yields of 33.0 % and 11.

Antioxidative Potency of Dolphin Serum Albumin Is Stronger Than That of Human Serum Albumin Irrespective of Substitution of Cysteine With Serine.

Serum albumin (SA), the most abundant protein in circulation, functions as a carrier protein, osmoregulator, and antioxidant. Generally, SA exerts its antioxidative effects by scavenging reactive oxygen species. Because marine mammals are superior divers, they are intermittently exposed to oxidative stress induced by rapid reperfusion of oxygen to ischemic tissues after the dive.