Cell surface structure enhancing uptake of polyvinyl alcohol (PVA) is induced by PVA in the PVA-utilizing Sphingopyxis sp. strain 113P3.
Polyvinyl alcohol (PVA)-utilizing Sphingopyxis sp. 113P3 (re-identified from Sphingomonas sp. 113P3) removed almost 0.5% PVA from culture supernatants in 4 days. Faster degradation of 0.5% PVA was performed by the periplasmic fraction. The average molecular size of PVA in the culture supernatant or cell-bound PVA was gradually shifted higher, suggesting that lower molecular size molecules are degraded faster. Depolymerized products were found in neither the culture supernatant nor the cell-bound fraction; however they were recovered from the periplasmic fraction. As extracellular or cell-associated PVA oxidase activity was almost undetectable in strain 113P3, degradation of PVA must be performed by periplasmic PVA dehydrogenase after uptake into the periplasm. Following the consumption of PVA, a dent appeared on the cell surface on day 2 and increased in size and depth for 4 days and was maintained for 8 days. Ultrastructural change on the cell surface was only observed in PVA medium, but not in nutrient broth (NB), suggesting that the change is induced by PVA. Fluorescein-4-isothiocyanate-labeled PVA was bound more to cells grown in PVA than to cells grown in NB. No binding was found with PVA-grown cells treated with formaldehyde. Thus, a dent on the cell surface seems to be related to the uptake of PVA.
Hu
Xiaoping
X
Laboratory of Applied Microbiology, Research Institute for Bioresources, Okayama University, 2-20-1 Chuo, Kurashiki, Okayama 710-0046, Japan. fkawai@rib.okayama-u.ac.jp
Mamoto
Rie
R
Shimomura
Yumi
Y
Kimbara
Kazuhide
K
Kawai
Fusako
F
D000429:Alcohol Oxidoreductases / Q000737:chemistry / Q000378:metabolism; D001483:Base Sequence; D008855:Microscopy, Electron, Scanning / Q000379:methods; D008856:Microscopy, Fluorescence / Q000379:methods; D008969:Molecular Sequence Data; D011142:Polyvinyl Alcohol / Q000378:metabolism / Q000493:pharmacokinetics*; D020578:Sphingomonas / Q000737:chemistry / Q000201:enzymology / Q000378:metabolism* / Q000648:ultrastructure*; D013329:Structure-Activity Relationship
D011142:Polyvinyl Alcohol; D000429:Alcohol Oxidoreductases; C048312:polyvinyl-alcohol dehydrogenase (acceptor); C048311:polyvinyl alcohol oxidase