Accelerated Degradation of four Organophosphorus Insecticides by Malathion Tolerant Aspergillus niger MRU01 a Soil Fungus

Abstract

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 as enhanced production of phosphatases and esterase enzyme as compared to untreated and treated wild type (A. niger ATCC16404). 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 tested in the microcosms more specifically for bioremediation of other OP insecticides before its application in the field.

HIGHLIGHTS

1. The malathion tolerant Aspergillus niger MRU01 grew efficiently in the presence of 500 μM malathion.

2. Treatment of the fungus with malathion and other OP insecticides – parathion, chlorpyrifos, and dimethoate – caused enhanced expression of phosphatases and esterases.

3. The tolerant A. niger MRU01 strain had significantly lower mycelia concentrations of insecticides than of the wild type A. niger ATCC16404.

4. Degradation of insecticides by the tolerant strain was significantly higher than by the wild type indicating its broad spectrum of tolerance.

Keywords:

• Aspergillus niger
• malathion mutant
• OP insecticides
• esterases
• phosphatases
• removal

Acknowledgments

The research was partly funded by Department of Science and Technology, Government of Odisha, and OHEPEE, Government of Odisha. The infrastructure grants of DST, Government of India under DST-FIST programme is gratefully acknowledged.

Authors’ contributions

All authors contributed to the study conception and design. Conceptualization, investigation, original draft was performed by Debasish Mohapatra. Data curation, formal analysis was done by Sakti Kanta Rath and project administration, data analysis, review and editing was performed by Pradipta K Mohapatra. All authors read and approved the final manuscript.”

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was supported by Department of Science and Technology, Government of Odisha, and OHEPEE, Government of Odisha. The infrastructure grants of DST, Government of India under DST-FIST