Isolation and characterization of monocrotophos degrading activity of soil fungal isolate Aspergillus NigerMCP1 (ITCC7782.10)

Monocrotophos (MCP) is both a systemic and control pesticide useful for the protection of various cash crops. The use of pesticide degrading microbial system for the removal of pesticide residue and other products from contaminated systems requires an understanding of the growth requirements of degrading organisms. Monocrotophos (MCP) degrading fungal strain was isolated from soil by enrichment culture. The fungal strain was identified by colony morphology, staining and 18S rDNA analysis as Aspergillus niger (MCP1) (ITCC 7782.10) GenBank accession no JQ660373. Monocrotophos degrading ability of the MCP 1 was characterized as assessment of two parameters i.e growth kinetics of fungal strains in the presence of monocrotophos by dry mass estimation method and degradation kinetics of monocrotophos by spectrophotometric method of estimation at 254nm. Growth kinetics revealed that monocrotophos had induced the growth of MCP 1 to approximately 2 folds. Culture conditions for the growth of MCP 1 were optimized by growing it under different physical and chemical parameters. Optimum conditions for growth were found to be pH-8, Temperature 25–30°C and monocrotophos concentration 150 mg L⁻¹. Aspergillus niger is capable of degrading 90% monocrotophos under optimized conditions in 10 days. Degradation kinetics of monocrotophos followed straight line equation and half life was thus calculated. Constant of degradation Kdeg was 0.009212 and the half life of monocrotophos was 75.87 hrs. In our study it is the first report showing the potential of Aspergillus niger as a potential degrader of monocrotophos and can be used as a candidate for removal of monocrotophos from agricultural sites.