The present book meets the requirement of the students of Microbiology, Biotechnology, Life Sciences and Environmental Sciences. It provides the fundamental knowledge on the microbial diversity, processes and applications in the environment. This can also be used as a source of basic knowledge for the researchers in the field of environmental microbiology. This book contains Microbial approaches to wastewater treatment Microbial diversity and processes in different habitats The microbiology of extreme environment Microbial remediation of wasteland and pesticide contaminated habitats Microbial interactions in the environment and their role in the environmental processes Symbiotic interaction of microbes with plants and animals and their role in ecosystem stability The rhizosphere microbiology and its role in plant productivity Microbial processes in saline and freshwater habitats Microbial mobilization of nutrients with special reference to the mobilization of nitrogen and phosphorus Advanced methodologies to study the microbial diversity and phylogenetic relationship in the environment Microbial remediation of the metal contaminated habitat Microbial mobilization and recovery of valuable metals from low grade ores and diluted solutions Microbial degradation of recalcitrant pollutant Determination of the environmental quality by microbial indication