Differences in 2,6-Dimethoxy-1,4-benzoquinone Reduction Systems between Brown-rot and White-rot Fungi

Biodegradation of nitro-substituted explosives by white-rot fungi: A mechanistic approach

Contamination of soils and aquifers by aliphatic halocarbons is a serious environmental pollution problem. We report here the novel observation that the halocarbons trichloroethylene (TCE) and CCl 4 were mineralized by Phanerochaete chrysosporium under aerobic conditions. Ligninolytic cultures of this white rot fungus mineralized 20.3% of 10 ppm TCE and 18.8% of 10 ppm CCl 4 in 9 days. These chemicals were not mineralized by nonligninolytic cultures of P. chrysosporium, indicating that lignin peroxidases play an important role in the mineralization of these chemicals. In a previous study, we reported lignin peroxidase-catalyzed reductive dehalogenation of CCl 4 with the resultant formation oftrichloromethyl radical. We have extended this study and report here reductive dehalogenation of CHCl 3 , CH 2 Cl 2 , TCE, and 1,1,1-trichloroethane. Dehalogenation was catalyzed by a reductive reaction system containing lignin peroxidase, veratryl alcohol, EDTA or oxalate, H 2 O 2 , and the halocarbon with phenyl N-tert-butylnitrone as a spin trap for electron spin resonance detection of the resulting radicals. Since all the components of the reductive system with oxalate as an electron donor are excreted by P. chrysosporium, we propose that this mechanism may be involved in the degradation of these halocarbons by the fungus.

Asymmetric reduction of ketones via whole cell bioconversions and transfer hydrogenation: complementary approaches