Current approaches in Bioremediation of toxic contaminants by application of microbial cells; biosurfactants and bioemulsifiers of microbial origin

Abstract

The increase in global human population has resulted in swift and extensive urbanization and industrialization. These anthropogenic activities along with natural phenomena result in the release of toxic compounds in the environment. These toxic compounds are recalcitrant in nature and accumulate in the environment, contaminating the soil and aquatic ecosystems. They pose a risk to human health and ecosystem through the contamination of drinking water, ingestion through the food chain and reduction in water and food quality. Microorganisms such as bacteria, fungi, yeast and algae possess various mechanisms that metabolize and detoxify these toxic pollutants. In this chapter, we emphasize the use of these microorganisms for bioremediation of toxic pollutants like heavy metals such as Cd, Hg, Pb, Zn, Cu and others; polyaromatic hydrocarbons and petroleum-based hydrocarbons; plastic polymers and recalcitrant dyes and agro-based compounds. Apart from naturally occurring microorganisms, genetically engineered microorganisms have been designed to degrade these recalcitrant toxic compounds. Bioremediation using both these natural and genetically engineered microbes is an economic and eco-friendly alternative to conventional physicochemical technologies.