This edited volume on Microbial Diversity includes the chapters on different aspects of microbial diversity, its exploration and exploitation. The contents are broadly categorized into two parts. Part-A includes 25 review articles on diverse aspects of microbial diversity and its applications, contributed by subject experts working in their respective areas. These areas include biotechnology, environment, agriculture, food, public health and nanotechnology. These review articles bring out update information available on selected topics and point out the gaps in our knowledge and further project future lines of research. Part-B includes original research papers on contemporary research areas contributed by active researchers. This book caters the long left needs of university teachers, researchers, students, and industrial entrepreneurs.