title: Accelerated biodegradation of poly(vinyl alcohol) by glycosidations of the hydroxyl groups or addition of sugars.
abstract: Biodegradabilities of N-acetyl-d-glucosamine (GlcNAc)- (1) and chitobiose-substituted (2) poly(vinyl alcohol)s (PVA)s in a soil suspension (pH 6.5) were investigated at 25 degrees C for 40 days. Biochemical oxygen demand of 1 with a degree of substitution of 0.2-0.3 (DP = 430-480) was higher than that of PVA under the degradation condition. Size exclusion chromatography, (1)H NMR, and Fourier-transform infrared measurements of the recovered sample indicated that biodegradation of the PVA main chain was accelerated by partial glycosidation of hydroxyl groups in PVA. Similar acceleration was observed in a PVA/GlcNAc (50:50, w/w) mixture. Microbes which relate with degradation of the glycosidated polymers were grown in a culture medium including the soil suspension and the polymer as the carbon source. Polyacrylamide gel electrophoresis (SDS-PAGE) and IR measurements indicated that a cell-free extract derived from GlcNAc-substituted PVA was different from that in the PVA/GlcNAc mixture. The results suggested that the PVA main chain in GlcNAc-substituted PVA was cleaved by a different microorganism or via a mechanism different from that in the mixture. Chitobiose-substituted PVA 2 showed more enhanced acceleration, indicating that the sugar length influenced the degradability.
authors.affiliation: Department of Environmental Technology and Urban Planning, Graduate School of Engineering, Nagoya Institute of Technology, Gokiso-cho, Showa-ku, Nagoya 466-8555, Japan. takasu.akinori@nitech.ac.jp
authors.forename: Akinori
authors.initials: A
authors.lastname: Takasu
authors.forename: Mizuho
authors.initials: M
authors.lastname: Takada
authors.forename: Hisashi
authors.initials: H
authors.lastname: Itou
authors.forename: Tadamichi
authors.initials: T
authors.lastname: Hirabayashi
authors.forename: Takatoshi
authors.initials: T
authors.lastname: Kinoshita
mesh_terms: D001673:Biodegradation, Environmental; D002241:Carbohydrates / Q000737:chemistry*; D002850:Chromatography, Gel; D004591:Electrophoresis, Polyacrylamide Gel; D005583:Fourier Analysis; D006027:Glycosides / Q000737:chemistry*; D017665:Hydroxyl Radical / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy
chemical_list: D002241:Carbohydrates; D006027:Glycosides; D017665:Hydroxyl Radical