Degradation of organophosphate insecticide by a novel Bacillus aryabhattai strain SanPS1, isolated from soil of agricultural field in Burdwan, West Bengal, India

• First report of biodegradation of OP compound by a novel strain of bacterium belonging to Bacillus aryabhattai.
• A pathway for degradation of parathion by a strain belonging to B. aryabhattai.
• First report of OP degrading bacterium from Burdwan, (well known for cultivation of paddy and potato), West Bengal in India.
• Mineralization of parathion by B. aryabhattai.

Organophosphate (OP) insecticides are widely used for controlling insect pests for better crop production in India. But indiscriminate use and lack of proper technical knowhow have resulted in contamination and pollution of large varieties of ecological niches. A novel bacterial strain designated as SanPS1, capable of utilizing chlorpyrifos and parathion, was isolated by enrichment culture from a soil sample of an agricultural field located at Narigram in Burdwan district of West Bengal, India. This novel Gram positive, endospore forming strain was identified as Bacillus aryabhattai based on 16S rDNA sequencing. The strain tolerated up to 500 μg mL−1 of chlorpyrifos and parathion and for both compounds optimal degradation was achieved at a concentration of 200 μg mL−1. The metabolites were identified by high performance liquid chromatography and gas chromatography-mass spectrometry analyses. We propose a degradation pathway of parathion for this strain through formation of 4-nitrophenol and 4-nitrocatechol intermediates. The strain could degrade approximately 56% of parathion in liquid mineral medium within 24 h at 37 °C.