title: Characterization of β-N-acetylglucosaminidase from a marine Pseudoalteromonas sp. for application in N-acetyl-glucosamine production.
abstract: The psychrotolerant Pseudoalteromonas issachenkonii PAMC 22718 was isolated for its high exo-acting chitinase activity in the Kara Sea, Arctic. An exo-acting chitinase (W-Chi22718) was homogeneously purified from the culture supernatant of PAMC 22718, the molecular weight of which was estimated to be approximately 112 kDa. Due to its β-N-acetylglucosaminidase activity, W-Chi22718 was able to produce N-acetyl-D-glucosamine (GlcNAc) monomers from chitin oligosaccharide substrates. W-Chi22718 displayed chitinase activity from 0 to 37°C (optimal temperature of 30°C) and maintained activity from pH 6.0 to 9.0 (optimal pH of 7.6). W-Chi22718 exhibited a relative activity of 13 and 35% of maximal activity at 0 and 10°C, respectively, which is comparable to the activities of previously characterized, cold-adapted bacterial chitinases. W-Chi22718 activity was enhanced by K+, Ca2+, and Fe2+, but completely inhibited by Cu2+and SDS. We found that W-Chi22718 can produce much more (GlcNAcs) from colloidal chitin, working together with previously characterized cold-active endochitinase W-Chi21702. Genome sequencing revealed that the corresponding gene (chi22718_IV) was 2,856 bp encoding a 951 amino acid protein with a calculated molecular weight of approximately 102 kDa.
authors.affiliation: a Division of Life Sciences , Korea Polar Research Institute , Incheon , South Korea.
authors.forename: Ha Ju
authors.initials: HJ
authors.lastname: Park
authors.affiliation: a Division of Life Sciences , Korea Polar Research Institute , Incheon , South Korea.
authors.forename: Joung Han
authors.initials: JH
authors.lastname: Yim
authors.affiliation: a Division of Life Sciences , Korea Polar Research Institute , Incheon , South Korea.
authors.forename: Hyun
authors.initials: H
authors.lastname: Park
authors.affiliation: a Division of Life Sciences , Korea Polar Research Institute , Incheon , South Korea.
authors.forename: Dockyu
authors.initials: D
authors.lastname: Kim
mesh_terms: D000117:Acetylglucosamine / Q000378:metabolism*; D000118:Acetylglucosaminidase / Q000378:metabolism*; D002686:Chitin / Q000378:metabolism; D002688:Chitinases / Q000378:metabolism; D006868:Hydrolysis; D007218:Industrial Microbiology; D007700:Kinetics; D031161:Pseudoalteromonas / Q000201:enzymology* / Q000378:metabolism; D013379:Substrate Specificity; D013696:Temperature
chemical_list: D002686:Chitin; D002688:Chitinases; D000118:Acetylglucosaminidase; D000117:Acetylglucosamine
keywords: N-acetyl-glucosamine; arctic marine; cold-active; exochitinase; psychrotolerant; β-N-Acetylglucosaminidase