Biodegradation is a process by which microbial organisms (mainly bacteria and fungi) transform or alter the structure of chemicals introduced into the environment. Bioremediation uses microorganisms to degrade organic contaminants in soil, groundwater, sludge, and solids. The microorganisms break down contaminants by using them as an energy source or cometabolizing them with an energy source. Microorganisms attach to the surface of polymers and degrade these polymers by secreting enzymes in order to obtain energy for their growth. Large polymers degraded into monomers and oligomers that are low molecular weight molecules. Natural and synthetic plastics are degraded by the action of microorganisms including bacteria, actinomycetes, and fungi. Bioremediation uses micro-organisms to reduce pollution through the biological degradation of pollutants into non-toxic substances. This can involve either aerobic or anaerobic micro-organisms that often use this breakdown as an energy source.

Various microorganisms can degrade environmental pollutants with promising skills like bacteria, fungi, algae, and protozoa. Certain parameters must be established to provide the highest biodegradation rate of degradable microorganisms under the optimum conditions. Micro-organisms are naturally-occurring and most of them are harmless. Many of them play key roles in the ecosystems, for instance by decomposing organic matter in the soil to make it available for other organisms, or by enriching the soil with atmospheric nitrogen to make it available for plants. Bioremediation is a process where biological organisms are used to remove or neutralize an environmental pollutant by metabolic process. The phenomena to treat any polluted or contaminated medium with the alteration of environmental conditions so as to trigger microbial growth hence degrade the target pollutants are bioremediation. Microorganisms help in cleaning up the environment. They decompose dead and decaying matter from plants and animals; convert them into simpler substances which are later used up by other plants and animals. Thus, they are used to breakdown harmful substances. The most significant effect of the microbes on earth is their ability to recycle the primary elements that make up all living systems, especially carbon, oxygen, and nitrogen. Primary production involves photosynthetic organisms which take up CO2 from the atmosphere and convert it to organic material. Yeast and other fungi are commonly used microorganisms. Organic Acids: Fungi are used to make organic acids. Fungi like Acetobacter, Rhizopus, and Penicillium are used to ferment fruits and sugar-containing syrups. Enzymes: Many microbes are utilized to make enzymes like lipase, lactase, protease, and peptidase.