Abstract
Several soil microbes, Mucor sufui and two other M. spp., Penicillium citrinum, P. glaucum, Aspergillus niger, Bacillus subtilis, Fusarium oxysporum and Trichoderma viride effectively degrade butachlor [2-chloro-2′, 6′-diethyl-N-(butoxy-methyl) acetanilide] in the 0.02M KH2PO4 buffer solution at pH 5.2 for fungi or pH 7.0 for bacteria. Three other soil microbes, A. oryzae, A. usamii and B. megatherium were found to be less effective, and Streptomyces sp. NTU-014 was unable to effectively degrade butachlor. Degradation of butachlor by M. sufui NTU-358 produced at least 8-12 metabolites. Among these products, 2-chloro-2′, 6′-diethyl-acetanilide, 2-hydroxy-2′, 6′-diethylacetanilide, 2, 6-diethylaniline, N-chloroacetyl-7-ethyl-2, 3-dihydroindole, 2′, 6′-diethylacetanilide and N-methyl-2-chloro-2′, 6′-diethylacetanilide were identified and the partial pathways involved in the degradation of butachlor were proposed. Recovery of butachlor in the autoclaved and non-autoclaved soils were found to be 74.5% and 26.3% respectively for 24 days incubation. It was presumed that the soil microbes may play an important role in the degradation of butachlor in soils.
