This book presents a detailed account of different enzymes including pectinolytic and amylolytic systems, invertases, cellulases and hemicellulases, pectinases, proteases, laccases, phytases, alpha-glucuronidases, mannanases, lipases produced by different fungi. It also deals with many applications, including the transesterification and biodiesel production. The text incorporates different approaches to diverse enzyme systems?for a better understanding of the substrates involved in catalysis?as well as different processes of enzyme production, purification processes, gene and metabolic regulations, and engineering of enzymes.