Many strains are known to be effective as bioremediation agents but only under laboratory conditions. Only certain species of bacteria and fungi have proven their ability as potent pollutant degraders. The process of bioremediation is a very slow process. As bioremediation can be effective only where environmental conditions permit microbial growth and activity, its application often involves the manipulation of environmental parameters to allow microbial growth and degradation to proceed at a faster rate (Figure 1). The process of bioremediation mainly depends on microorganisms which enzymatically attack the pollutants and convert them to innocuous products. One of these genes allows the plant to modify arsenate into arsenite and the second one binds the modified arsenite and stores it in the vacuoles. For instance arsenic is phytoremediated by genetically modified plants such as Arabidopsis thaliana which expresses two bacterial genes. Genetically, engineered plants are also in use. The process of phytoremediation is an emerging green technology that facilitates the removal or degradation of the toxic chemicals in soils, sediments, groundwater, surface water, and air (RTDF). The involvement of plants in the bioremediation of pollutants is called as phytoremediation. The employability of various organisms like bacteria, fungi, algae, and plants for efficient bioremediation of pollutants has been reported. The associated deficiencies in these methods have focused efforts towards harnessing modern-day bioremediation process as a suitable alternative.īioremediation is a microorganism mediated transformation or degradation of contaminants into nonhazardous or less-hazardous substances. These methods are complex, uneconomical, and lack public acceptance. Although they can be very effective at reducing wide a range of contaminants but at the same time have several drawbacks. New technologies for waste disposal that use high-temperature incineration and chemical decomposition (e.g., base-catalyzed dechlorination, UV oxidation) have evolved. This mode of waste disposal was difficult to sustain owing to lack of new place every time to dump. In the past, wastes were traditionally disposed by digging a hole and filling it with waste material. Unfortunately the progress in science, technology, and industry a large amount ranging from raw sewage to nuclear waste is let out or dumped into the ecosystem thereby posing a serious problem for survival of mankind itself on earth. The quality of life on the Earth is linked inextricably to the overall quality of the environment. This review attempts to provide descriptive information on the enzymes from various microorganisms involved in the biodegradation of wide range of pollutants, applications, and suggestions required to overcome the limitations of their efficient use. The information on the mechanisms of bioremediation-related enzymes such as oxido-reductases and hydrolases have been extensively studied. The research activity in this area would contribute towards developing advanced bioprocess technology to reduce the toxicity of the pollutants and also to obtain novel useful substances. Bioremediation is a cost effective and nature friendly biotechnology that is powered by microbial enzymes. A large number of enzymes from bacteria, fungi, and plants have been reported to be involved in the biodegradation of toxic organic pollutants.