Introducton -- History of industrial biotransformations : dreams and realities -- From the "flower of vinegar" to the recombinant E. coli : the history of microbial biotransformations -- From gastric juice to Sweetzyme T : the history of enzymatic biotransformations -- Advantages of biotransformations over classical chemistry -- Enzyme classification -- The enzyme nomenclature -- The enzyme classes -- EC1 Oxidoreductases -- EC2 Transferases -- EC3 Hydrolases -- EC4 Lyases -- EC5 Isomerases -- EC6 Ligases -- Basics of bioreaction engineering -- Definitions -- Biosynthesis and immobilization of biocatalysts -- Characteristics of the different enzyme classes -- Kinetics -- Basic reactor types and their mode of operation -- Processes