Microbial scission of sulfide linkages in vulcanized natural rubber by a white rot basidiomycete, Ceriporiopsis subvermispora.
A white rot basidiomycete, Ceriporiopsis subvermispora, degraded vulcanized natural rubber (NR) sheets on a wood medium. The fungus decreased the total sulfur content of the rubber by 29% in 200 days, accompanied by the cleavage of sulfide bonds between polyisoprene chains. X-ray photoelectron spectroscopy (XPS) demonstrated that C. subvermispora reduced the frequency of S-C bonds by 69% with a concomitant formation of S-O bonds during the culture period. Dipolar decoupling/magic angle spinning (DD/MAS) solid state 13C NMR revealed that the fungus preferentially decomposed monosulfide bonds linked to a cis- and trans-1,4-isoprene backbone but the cleavage of polysulfide bonds was also observed. In contrast, no decrease in weight or devulcanization of rubber was observed in cultures of a white rot fungus, Dichomitus squalens. The oxidative cleavage of sulfide bonds by C. subvermispora demonstrates that ligninolytic basidiomycetes are potential microbes for the biological devulcanization of rubber products.
Laboratory of Biomass Conversion, Wood Research Institute, Kyoto University, Gokasho, Uji, Kyoto 611-0011, Japan.
Shin
S
Sato
Yoichi
Y
Honda
Masaaki
M
Kuwahara
Hiroyuki
H
Kishimoto
Noriko
N
Yagi
Kiyoshige
K
Muraoka
Takashi
T
Watanabe
D001673:Biodegradation, Environmental; D009682:Magnetic Resonance Spectroscopy; D008855:Microscopy, Electron, Scanning; D020072:Polyporales / Q000737:chemistry* / Q000648:ultrastructure; D012408:Rubber / Q000737:chemistry*; D013052:Spectrometry, X-Ray Emission; D013440:Sulfides / Q000737:chemistry*; D013455:Sulfur / Q000032:analysis; D013499:Surface Properties
D013440:Sulfides; D013455:Sulfur; D012408:Rubber