Biodegradation of the sulfonylurea herbicide chlorimuron-ethyl by the strainPseudomonassp. LW3

The chlorimuron-ethyl-degrading bacterium LW3 was isolated from contaminated soil and identified by 16S rRNA gene sequencing as Pseudomonas sp. When chlorimuron-ethyl was provided as the sole nitrogen source, the degradation efficiency in liquid medium was about 81.0% after 7 days of inoculation with strain LW3. The effects of chlorimuron-ethyl concentration and temperature on biodegradation were examined. Two metabolites of degradation were analyzed by LC/MS. Based on the identified products, strain LW3 seemed to be able to degrade chlorimuron-ethyl by cleavage of the sulfonylurea bridge. The inoculation of strain LW3 to chlorimuron-ethyl-treated soil resulted in a higher degradation rate than in uninoculated soil, regardless of the soil being sterilized or nonsterilized. This microbial culture has great potential for the bioremediation of soil contaminated with chlorimuron-ethyl.