Table of Contents

ABSTRACT

Microorganisms have been using over the last 70 years for their uniqueness in improving agricultural productivity and environmental conditions, removing toxic chemicals from the environment, desulfurizing many fossil fuels, modeling of the ecosystem, controlling oil spillage, and saving of energy resources. Often for their unpredictable characteristics and biosynthetic capabilities to produce a certain set of environmental and cultural conditions lead them for solving particularly difficult problems in the life sciences and other fields as well in an economically effective and environmentally sustainable manner. Microorganisms achieved significant results in eliminating problems associated with the use of chemical fertilizers and pesticides; nowadays they are widely used in nature farming and organic agriculture. Numerous oleaginous yeasts, microalgae, bacteria, in particular, those of the actinomycete group offer great potential as a sustainable feedstock for the production of third-generation biofuels, such as biodiesel and bioethanol. Biological treatment methods involving microorganisms have been widely used to degrade chloro-organic pollutants and aromatic compounds, to remove heavy metals, wide variety chemicals of a complex structure like dyes having azo, aromatic and heterocyclic groups, surfactants, toxicants, and salts are being released in the effluent of the textile industry. Recently, bio-electrochemical systems (BES) such as microbial fuel cells (MFCs) and microbial electrolysis cells (MECs) have emerged as a promising technology for simultaneous energy recovery and wastewater treatment.