The Role of Microorganisms in Remediation of Environmental Contaminants

Environmental pollution by heavy metals, hydrocarbons, pesticides, dyes and other xenobiotic compounds is increasing day by day. Reclamation of these contaminants is of utmost importance for sustainable development. Various anthropogenic activities like industrial waste, mining, use of pesticides, deforestation and automobile emissions added a significant amount of these contaminants into the environment. Conventional remediation techniques such as physicochemical methods, electrochemical treatments and cationic and anionic exchange are relatively expensive and quite unsuccessful with minute concentration of pollutants. Besides these limitations, conventional methods also lead to the production of secondary pollutants. However, bioremediation employs the use of microbes as well as plants for the restoration of the environmental sites and water bodies. Exploitation of microbes such as bacteria, fungi and algae as remediation tools is emerging as an eco-friendly approach for the treatment of different pollutants and contaminants from air, soil and water. Comparing to conventional technologies, the microbe-based bioremediation is more economical and efficient in protecting the environment and minimizing the health hazards caused by pollutants. Nowadays, microbes have been also targeted using gene-editing tools such as genetic engineering, microarray technology and various omics approaches such as genomics, transcriptomics, metabolomics and proteomics for the regulation and optimization of the remediation process. Development in technology provides a new era of an integrated approach exploring the plant–microbe interaction and genetically engineered microbes for the restoration of polluted sites. This book chapter aims to summarize the different physiological, biochemical and molecular basis of remediation along with various advancements in remedial approaches for conserving an ecological balance by the use of microbes.