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.
Sato
Shin
S
Laboratory of Biomass Conversion, Wood Research Institute, Kyoto University, Gokasho, Uji, Kyoto 611-0011, Japan.
Honda
Yoichi
Y
Kuwahara
Masaaki
M
Kishimoto
Hiroyuki
H
Yagi
Noriko
N
Muraoka
Kiyoshige
K
Watanabe
Takashi
T
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