Abstract

Accumulation of obsolete pesticides in the environment is a global problem. The scale of the problem in different countries varies depending on economic situation and social awareness. Only limited data are available on the microbial biodegradation of butachlor. Biodegradation of butachlor by different microorganisms was investigated. Six bacterial strains were isolated from an agricultural soil and found to be actively utilized butachlor, as a sole source of carbon and energy. Based on their morphological and biochemical categorization, the six bacterial and fungal isolates were identified as Psedomonas alcaligens, Bacillus licheniformis, Bacillus megaterium, Trichoderma viride, Rhizobium huakuii and Bradyrhizobium japonicum. Results show that the Trichoderma viride andPsedomonas alcaligens quickly degraded butachlor and reached nearly 98 and 75% in a medium containing 50 mg/kg of butachlor after 15 and 21 days, respectively. Our results can conclude that these two organisms can be usedto degrade the obsolete butachlor formulation.

Key words: Obsolete pesticides, herbicide, butachlor, biodegradation