This new textbook on bacterial physiology is aimed at senior level students pursuing a one-semester course in the biology or microbiology curriculum. The text takes a balanced view of prokaryotic physiology, discussing both bioenergetics and bacterial metabolism in a way that establishes general principles and concepts and emphasizes throughout the information gained from model systems. The book also covers some experimental design issues, giving students an appreciation of the practical aspects and consequences of bacterial metabolism. It also stimulates students interests in future developments in the field by including discussions by five world-famous bacterial physiologists about future developments in the field.