Accelerated degradation of four OP insecticides by malathion tolerant Aspergillus niger M- RU01

Insecticides are widely used in agriculture, horticulture, medicine, and industry, as well as domestically. Increased insecticide application has been attributed to higher agricultural productivity and lower infield and postharvest crop loss in the twentieth century. Malathion is a very commonly used organophosphorus (OP) insecticide applied in over 100 food crops in agriculture and post-harvest storage. Different species of Aspergillus have shown their efficiency to degrade OP chemicals. A malathion tolerant Aspergillus niger MRU01, developed by prolonged malathion exposure, was tested for its efficiency to remove malathion as well as three other commonly used OP insecticides, viz., parathion, chlorpyrifos and dimethoate. The tolerant strain showed growth efficiency as well enhanced production of phosphatases and esterase enzyme as compared to untreated as well as treated wild type ( A. niger MTCC16404). The removal of malathion was 29% and 68%, in the wild type and the tolerant strain, respectively during five days. The tolerant strain was also able to remove dimethoate (63%) and chlorpyrifos (54%) with high efficiency while a low rate of removal of parathion (33%) was observed. The strain can be applied in field for bioremediation.