This book provides the basic concepts of biotransformation and its applications in the fields of pharmaceutical and food industries, as well as in drug development. It offers alternative solutions to conventional methods of chemical synthesis by providing examples that directly contribute to saving time, reducing costs, and providing the public safety necessary in drug manufacturing and development. This book explores how biological catalysts work to carry out reactions on natural and pharmaceutical compounds in single steps with high regio- and stereospecificity. The book also provides useful results that, in turn, lead to developments in the pharmaceutical and food industries.This book also establishes the principles of using sustainable green chemistry, which reduces the use of dangerous chemicals by workers and researchers.