Microbial metabolism in bioremediation: A review

Bioremediation is degradation of pollutants using biological mechanisms. Rapid industrialization and agricultural development has caused several pollutants and contaminants to percolate the environment in alarming proportions. To overcome the critical situation microbes play a vital role in eradication of pollutants. Release of toxins from pollutants enhances metabolic activities of a few stringent microorganisms, leading to decomposition of waste. Diverse population of fungi and bacteria play a key role in this process. Combined action of specific enzyme production and genetic regulation guides the metabolic removal of toxicants. Bioremediation is degradation of toxic compounds by plants or microbes, forming non-toxic products. In this process of decontamination, plants and microbes improve the nutritional and structural quality of soil by recolonizing it, enhancing potential for agricultural and industrial development. Bioaugmentation is a process employed for regulating microbial communities by introducing specific organisms to a contaminated site, in accordance with the specific properties of the contaminant and site. Bioaugmenation is related with ‘omics’ research, which helps in comprehending the metabolic approaches employed for degradation of toxins. The ‘omic’ studies like transcriptomics, genomics, proteomics and metabolomics not only disclose whether a certain organism can degrade the contaminant, but they also explain the process and products of reactions involved in decontamination. This leads to better understanding of protein and molecular mechanisms, which are significant for improving effectiveness and reducing cost. Furthermore, synergistic action of different microbes at the site of contamination, can be studied with the aid of ‘omics’, which yields more efficient, collaborative groups of microorganisms and more effective decontamination of toxicants. Current review analyses various bioremediation techniques, microorganisms participating and the genetic and molecular mechanisms involved.