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
Highlights
Herbicides are being increasingly used under intensive cultivations to control unwanted weeds, to minimize the cultivation cost as well as to sustain high yield
The aims of this study were the determination of the ability of six different microorganisms isolated from soil to transform obsolete butachlor formulation (Machete 60% EC), to investigate biodegradation rate of Machete 60% EC, and to provide basic information for developing regulations regarding the safe disposal of butachlor to protect the environment and public health
The experiment scheme was to determine which of the studied microorganisms, Psedomonas alcaligens, Bacillus licheniformis, Bacillus megatherium, Trichoderma viride, Rhizobium huakuii. and Bradyrhizobium sp. is butachlor resistant, and the materials consisting of such microorganisms were analyzed on microorganism's biodegrading butachlor content to determine if bacteria and fungi strains are responsible for biodegradation
Summary
Herbicides are being increasingly used under intensive cultivations to control unwanted weeds, to minimize the cultivation cost as well as to sustain high yield. The recent studies, reported that the application of butachlor has adverse environmental impact; butachlor was found to flow out with effluents, causing contamination of river and ground water (Natarajan et al, 1993; Ohyama et al, 1986; Yamagishi and Akiyama, 1981), it has toxicity to aquatic organisms (Ateeq et al, 2002; Ateeq et al, 2006; Lin, 1997), and it has genotoxicity to the amphibian animals (Geng et al, 2005). It could induce apoptosis in mammalian cells (Panneerselvam et al, 1999). With the progress of molecular biotechnology, evaluating the impact of pesticides application on ecological environment is more thorough and accurate using amplified (DNA) fragment length polymorphism (AFLP), amplified ribosomal DNA restriction analysis (ARDRA) (Vandamme et al, 1996; Vaneechoutte, 1996), and denaturing gradient gel electrophoresis (DGGE) (Muyzer, 1999; Muyzer et al, 1993)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
