Chapter 5 - Biodegradation and bioaugmentation of pesticides using potential fungal species

Abstract

Pesticides play a remarkable role in ensuring food security. They are used in both human and animal health initiatives, in addition to eliminating pests in agriculture. However, the usage of biopesticides differs from that of chemical pesticides. Chemical pesticides may cause rapid degradation in surface and ground waste, especially in places of agricultural activity, but may end up with serious consequences to the environment and human health, and this is a major source of soil pollution. Microorganisms such as bacteria, fungi, and algae can be employed to remove organic (or inorganic) contaminants from the soil as well. Microbes can totally metabolize contaminants or change their chemical structure, allowing them to degrade more quickly and reduce the contamination level in the environment. Bacteria have metabolized a number of substances and chemically generated compounds, including organic complexes, heavy metals, and chlorinated and nonchlorinated insecticides. Enzymes are important in the biodegradation of any xenobiotic and help to restore the polluted environment in the future by refurbishing pollutants at a rapid rate. Pesticides are also degraded by enzymes in the target organism via natural detoxification mechanisms and acquired metabolic tolerance, as well as in the broader environment via soil and water microorganism biodegradation. To eliminate polyaromatic hydrocarbon pollutants from fresh, marine, and terrestrial water, fungal enzymes such as oxidoreductase, laccase, and peroxidases are commonly utilized. The purpose of this study is to study the potential of selectable fungal strains. Herbicides, fungicides, and pesticides are all biodegradable. Fungi are one of these bio-resources that have been extensively researched and used for pesticide biodegradation and bioremediation. In total, 40 fungal strains were isolated and identified in soil and liquid media. Pesticides such as lindane, methamidophos, endosulfan, chlorpyrifos, atrazine, cypermethrin, dieldrin, methyl parathion, and heptachlor were found to be degraded effectively by 15 of the 40 isolates. On the other hand, soil moisture content, nutrient availability, pH, temperature, oxygen level, and other parameters all influence the rate of pesticide degradation by fungi. Fungal strains were discovered to be utilized in processes such as hydroxylation, demethylation, dechlorination, dioxygenation, esterification, dehydrochlorination, and oxidation, during the biodegradation of numerous pesticides with variable functional groups. Several enzymes, including laccase, hydrolases, peroxidase, esterase, dehydrogenase, manganese peroxidase, and lignin peroxidase, have been involved in the biodegradation of pesticides. The findings were thoroughly addressed.