Evaluation of Bacillus sp. strain isolated from pesticide influenced rhizospheric soil for dimethoate degrading potential.

Pesticides play a major role in the current scenario of Indian agriculture. Agriculture is a backbone of the country's economy contributing to 54% of employment. Being a vastly populated country, food aid dependency rate is very high. To meet the requirements of such a huge supply, high crop yields are necessary to sustain the food security. Thus, an abundance use of pesticides is quite common, ranking among the top producers of pesticide in the world. Organophosphates (OPP) being one of the major pesticides used in India. Known for causing acute toxicity, organophosphate pesticides are needed to be used controllably, and residues released into the environment should be treated to render them harmless. Biological degradation is one of the most effective ways to achieve that. However, exploring potential candidate for the purpose is still not sufficient compared to the necessity to alleviate organophosphates from the environment. This study examines the microbial degradation of dimethoate, an organophosphate pesticide, using Bacillus paramycoides. These bacteria were isolated from the rhizospheric soil of sugarcane fields in Sevur, Tamil Nadu, India, which has been exposed to dimethoate for over 10 years. The strain has been extensively studied to check its prospect for environmental stress, pesticide tolerance, and degradation efficiency. Degradation of dimethoate was detected by Fourier transform infra-red spectroscopy (FTIR) analysis. The isolate was found to degrade dimethoate by 97.6% in 5 days with a tolerance of 1000ppm for the targeted pesticide. Emphasis have also been placed on detecting the secondary metabolites produced by the isolate using gas chromatography-Mass spectrometry(GC-MS) analysis, in which, a compound Phosphorothioic O, O,S-acid, a probable by-product of dimethoate degradation was identified. Significant other biologically important metabolites obtained from B.paramycoides, have also been reported in this study, which are known to have different anticancerous and antibacterial properties.