Strategies in microbial degradation enhancement of chlorpyrifos – a review based on the primary approaches in soil bioremediation
Edna Mary Varghese, P S Aswani, M. S. Jisha
Abstract
The worldwide demand for potential agrochemicals is escalating day-by-day. Unsystematic and widespread pesticide use has resulted in constant expansion of pesticide industry making them the leaders of the agrochemical industry. The consumption of organophosphate pesticides is rapidly rising leading to its persistence in the environment thereby resulting in environmental contamination. Chlorpyrifos (O,O-diethyl O-(3,5,6-trichloro-2-pyridyl) phosphorothioate) is the most broadly used wide-spectrum chlorinated organophosphate pesticide. The toxic effects of chlorpyrifos on crop plants, aquatic life and human health is of great concern. Being a systemic pesticide, its soil residual effect would be a menace to sustainable agriculture practices. Degradation of chlorpyrifos in the environment into simpler non-toxic metabolites would be the only available solution to this endless dilemma. Chlorpyrifos can undergo either biological or non-biological transformation in the environment among which biological degradation involving microorganisms has been considered as cost-effective and environment-friendly. Recent advances in the primary approaches of soil pesticide biodegradation such as biostimulation and bioaugmentation along with cell immobilisation technique have paved ways for complete and effective chlorpyrifos detoxification. Various mechanisms and contributions in chlorpyrifos biodegradation and degradation enhancement approaches are discussed in detail in this review.