Bioremediation is a process through which toxic pesticides can be removed completely or their chemical nature can be altered to have no or less adverse impact on the environment. Microorganisms possess the ability to degrade or alter the toxic nature of chemical pesticides into non-toxic substances, and this ability is exploited in bioremediation.

A good number of microorganisms are capable of wide spectrum metabolism. These include bacteria, fungi, algae and other microbial strains. Many microorganisms utilize chemicals to derive energy and possess enzymes capable of degrading such pesticides. Examples include Pseudomonas, Aerobactor, Acinetobacter, Plesiomonas, Neisseria, Sphingomonas, and Flavobacterium.

During bioremediation, xenobiotic substances are subjected to enzymatic action present in microorganisms. The most immediate enzyme actions on pesticides include oxidation-reduction reactions, hydrolysis, and transferase activities of cytochrome, peroxidase esterase, and transferase enzymes. Some microorganisms also possess genes whose products are capable of degrading pesticides.

The process depends on several factors. Environmental conditions like temperature, humidity, pH, salinity, nutrition, and presence of CO₂ and O₂ are crucial. The microbial species present and their adaptability with the pesticide is important. Additionally, the structure of pesticide affects the process, as polymeric xenobiotic compounds are comparatively less biodegradable than lower molecular weight compounds.

Simultaneous use of a conglomerate of microorganisms for biodegradation has been observed to yield better results, provided conditions for sustenance and enzymatic activity of microorganisms are conducive.