Environmental Contamination by Pesticide Residues and Their Biodegradation Mechanisms: A Review

The widespread use of pesticides in modern agricultural practices has resulted in the accumulation of pesticide residues in the environment, including the soil, water, and food systems. This has raised critical questions regarding the stability of the ecosystem. The need for an in-depth knowledge of the processes of degradation of pesticide residues is imperative for the reduction of environmental hazards. In this review, the distribution of pesticide residues in the interrelated food–water–soil systems are reviewed, with special attention given to the process of biodegradation of pesticides by microorganisms. The role of bacteria, fungi, and algae in the transformation of pesticides is reviewed, with special attention given to the production of transformation products, which may have different properties compared with the original compound, particularly in the aquatic system. The review also evaluates limitations of biodegradation under field conditions, where factors such as sorption -aging processes, environmental variability, reduced bioavailability, and microbial competition can limit remediation efficiency. Strategies to enhance degradation, including bioaugmentation, biostimulation, and the development of microbial consortia supported by omics-based identification of functional degraders, are also explored. By integrating knowledge of pesticide transport, transformation, and microbial degradation, this review provides a comprehensive perspective for improving monitoring and developing field related remediation strategies. Such an integrated approach can support sustainable pesticide management while protecting ecosystem integrity and public health.