In recent decades, rapid industrialization has significantly increased the level of toxic and hazardous chemicals in the environment which further adversely affects human health and the other organisms as well in one hand. While on the other, a rapidly mounting human population and their demand for food, fuel, and other necessities have remarkably increased the complexity of toxic effluents in the air, soil, and water. Conventional approaches to remove these contaminants from the environment are time- and cost-consuming. Recent understating of microbial metabolism, their occurrence in a diverse environment, cost-effectiveness, and eco-friendly nature has made them suitable for remediation of the environmental pollutants. Among these cyanobacteria are common phototropic microorganisms which play a distinct role in the ecosystem and can survive in a variety of environment. Diazotrophic cyanobacteria are capable of fixing atmospheric nitrogen and carbon and thus increase the fertility of the contaminated soil, and they are being used for reclamation of usar/alkali soil in one way, while on other contributes to a significant proportion in global carbon fixation.

Additionally, they are capable enough to remove/degrade the heavy metals from the contaminated sites by modifying their metabolic activities. Desirable traits of these microbes can be obtained by genetic engineering with increased efficiency to degrade the organic pollutants. In this chapter, the contribution of cyanobacteria to environmental remediation has been discussed.