Evaluation of monocrotophos residues in soils of bathinda, punjab and its viodegradation through microbial isolates of contaminated soil

Abstract

The soil samples for the study were randomly collected from ten different villages (Bhagibander, Dhadde, Gurusar Sahnewala, Jajjal, Jassi, Malkana, Mahinangal, Sangat Kalan, Talwandi sabo, Teona Pujarian) of Bathinda. The questionnaire survey provided the information on pesticide history and consumption. All the villages had the history of monocrotophos (MCP) usage for crops like cotton, rice and legumes and two villages Dhadde and Teona Pujarian had current monocrotophos usage. The MCP residue of 0.08 ?g/kg was detected only in Teona Pujarian soil sample. The screening of all soil samples for the microbes with tolerance for different monocrotophos concentrations of 50 mg/l to 1000 mg/l in pikovskaya media was done by enrichment and adaptation method. The two bacterial isolates named as D1, T1 and four fungal isolates D2, D3, T2, and T3 were isolated from Dhadde (D) and Teona Pujarian (T) soil at MCP concentration of 1000mg/L. The morphological and biochemical test results for bacterial isolates from Teona Pujarian, T1 and Dhadde, D1 were found similar to Pseudomonas sp. and Serratia sp. respectively. The fungal isolates were found to have similar morphological characters to Aspergillus sp. The isolate T1 showed the degradation potential of 88.9 % in media and 87.4% in the MCP spiked soil after 7 days for MCP concentration of 1000 mg/L. The increase in P solubilisation and detection of traces of MCP residues and volatile fatty acids like palmitic acid, stearic acid, etc. indicated MCP mineralization by the isolate. This isolate could be useful in on-site bioremediation of the monocrotophos contaminated soil