Remediation of chemical pesticides from contaminated sites through potential microorganisms and their functional enzymes: Prospects and challenges

In modern agriculture, chemical pesticides are widely used to protect crop plants from insects and microbial pests, but the improper application of synthetic chemicals is hazardous for non-targeted organisms and the environment of the applied sites. The disposition mechanism of applied pesticides is highly variable in global farmlands; therefore, the sustainable remediation of pesticide-contaminated sites is a priority research area for the ecofriendly management of these pollutants. Furthermore, researchers discourage the physical and chemical remediation of pesticides and their metabolites because of issues related to time consumption, cost effectiveness, and sustainability compared to microbial and enzymatic remediation. Microorganisms from diverse taxonomic groups, such as bacteria, fungi, and algae, are known to effectively metabolize pesticides and/or alter the chemical structures facilitating their degradation and making the contaminated environment free from harmful pesticide residues. Similarly, catalytic enzymes, such as laccase and peroxidase, can also efficiently remediate most organic and chemical pesticides. The elite strains of microorganisms, singly or as a mixed consortium, can be used for compelling biological pesticide remediation. However, several research uncertainties, including inconsistent performance, adaptation under varying weather conditions, and application difficulties, may limit the wider practical application of these potential ecofriendly bioremediation approaches. This study reviews recent literature on the prospect and challenges of ecofriendly bioremediation approaches for the reclamation of pesticide-contaminated sites. This study also discusses the underlying mechanism of the microbe- and enzyme-mediated bioremediation of pesticides with a sustainable research prospective.