An organophosphorus pesticide malathion biodegradation was investigated by using the bacteria Ochrobactrum sp. M1D isolated from a soil sample of peach orchards in Palampur, District Kangra, Himachal Pradesh (India). The bacterium was able to utilize malathion as the sole source of carbon and energy. The isolated bacterium was found psychrotolerant and could degrade 100% of 100 mg l⁻¹ malathion in minimal salt medium at 20°C, pH 7·0 within 12 days with no major significant metabolites left at the end of the study. Through GCMS analysis, methyl phosphate, diethyl maleate, and diethyl 2-mercaptosuccinate were detected and identified as the major pathway metabolites. Based on the GCMS profile, three probable degradation pathways were interpreted. The present study is the first report of malathion biodegradation at both the psychrophilic and mesophilic conditions by any psychrotolerant strain and also through multiple degradation pathways. In the future, the strain can be explored to bio-remediate the malathion contaminated soil in the cold climatic region and to utilize the enzymatic systems for advanced biotechnology applications.

中文翻译：

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耐冷细菌 Ochrobactrum sp. 对马拉硫磷的生物降解。M1D和代谢途径分析

通过使用细菌Ochrobactrum sp.研究了有机磷农药马拉硫磷的生物降解。M1D 从喜马偕尔邦（印度）康格拉区帕兰普尔的桃园土壤样本中分离出来。该细菌能够利用马拉硫磷作为碳和能量的唯一来源。发现分离的细菌具有耐寒性，可以 100% 降解 100 mg l ^-1马拉硫磷在 20°C、pH 7·0 的基本盐培养基中在 12 天内，在研究结束时没有留下主要的显着代谢物。通过 GCMS 分析，磷酸甲酯、马来酸二乙酯和 2-巯基琥珀酸二乙酯被检测并鉴定为主要途径代谢物。基于 GCMS 配置文件，解释了三种可能的降解途径。本研究是关于任何耐寒菌株在嗜冷和嗜温条件下以及通过多种降解途径进行马拉硫磷生物降解的第一份报告。将来，可以探索该菌株在寒冷气候地区对马拉硫磷污染的土壤进行生物修复，并将酶促系统用于先进的生物技术应用。