Characterization of an extracellular poly(3-hydroxy-5-phenylvalerate) depolymerase from Xanthomonas sp. JS02.
A bacterium, JS02, capable of degrading an aromatic medium-chain-length polyhydroxyalkanoate (PHA(MCL)), poly(3-hydroxy-5-phenylvalerate) (PHPV), was isolated from wastewater-treatment sludge (Ju et al. 1998), and was identified as a Xanthomonas species. An extracellular PHPV depolymerase was purified from the concentrated culture broth of Xanthomonas sp. JS02 by using a chromatography series on Sephadex G-75, QAE-Sephadex A-50 and hydroxyapatite. The molecular mass of the purified enzyme was estimated to be 41.7 kDa. The purified enzyme could hydrolyse PHPV and p-nitrophenyl (PNP)-esters of fatty acids, but did not hydrolyse short-chain-length PHAs, though the culture supernatant could hydrolyse them. The optimum pH range was 8.0-9.0 and the optimum temperature was 60 degrees C for PNP-octanoate hydrolysis. The Km values for PNP-hexanoate and PNP-octanoate were 10.9 and 0.88 microM, respectively.
Kim
H
H
Department of Agricultural Chemistry, Sunchon National University, Korea. hoon@sunchon.sunchon.ac.kr
Ju
H S
HS
Kim
J
J
D001673:Biodegradation, Environmental; D002265:Carboxylic Ester Hydrolases / Q000302:isolation & purification* / Q000378:metabolism*; D011091:Polyesters / Q000378:metabolism*; D012722:Sewage / Q000382:microbiology; D014865:Waste Disposal, Fluid; D014974:Xanthomonas / Q000201:enzymology* / Q000302:isolation & purification
D011091:Polyesters; D012722:Sewage; C400742:poly(3-hydroxy-5-phenylvalerate); D002265:Carboxylic Ester Hydrolases; C077226:poly(3-hydroxyalkanoic acid) depolymerase