The breakdown of organic substances by microorganisms such as bacteria and fungi is known as biodegradation. Biodegradation is a natural process that recycles biologically necessary materials in the Earth's biogeochemical cycles. It is largely mediated by microbes. Enzymes that are arranged in pathways that transform compounds via a sequence of intermediates into end products commonly catalyse biodegradation processes. Mineralization is the process of converting a chemical into fully oxidised compounds. Biodegradation is carried out by a variety of organisms in principle, but we consider microbiological biodegradation to be the most relevant from an environmental standpoint in most circumstances. Microorganisms' rates of biodegradation in water and soil are of particular interest.
Bioremediation is a method of treating contaminated media, such as water, soil, and subterranean material, by modifying environmental conditions to encourage microorganism growth and degradation of the target pollutants. Oil spills, soils contaminated with acidic mining drainage, underground pipe breaches, and crime scene cleanups are all examples of bioremediation in action. Enzymes found in microbes detoxify these toxic compounds. The majority of bioremediation processes involve oxidation-reduction reactions, in which an electron acceptor (typically oxygen) is added to stimulate the oxidation of a reduced pollutant (e.g., hydrocarbons) or an electron donor (typically an organic substrate) is added to reduce oxidized pollutants. Bioremediation is a technique for reducing the impact of anthropogenic by-products such as those produced by industrialization and agricultural processes.