This book provides the readers with basic as well as advanced knowledge on microbial enzymes especially phytases. Phytases are a group of enzymes which hydrolyse phytic acid(a major constituent of cereals, legumes and oil seed crops) to less phosphorylated myo-inositol derivatives releasing inorganic phosphate. Although phytases can be derived from a host of sources, microorganisms are more promising for the production of phytases on a commercial scale. It discusses the concepts of isolation and purification of phytases from microbes. Various methods of optimization of media and fermentation parameters for maximum production of phytase are discussed in detail.The molecular, biophysical and biochemical characteristics of phytases are described. The book also covers the applied aspects of phytases such as their role in animal & human nutrition and in agriculture.The book will be beneficial to Undergraduate, Post Graduate students and Research scholars of Life Sciences.The systematic discussion of each topic added with references to information from current scientific publications would be of great value to readers to know the constantly evolving and challenging field of this science.