Biocatalysis has become an essential tool in the chemical industry and is the core of industrial biotechnology, also known as white biotechnology, making use of biocatalysts in terms of enzymes or whole cells in chemical processes as an alternative to chemical catalysts. That this is no longer a vision is to be seen from the many areas of daily life where biocatalysts with their environment-friendly properties are currently employed. Drivers are the big societal challenges resulting from concerns about the global climate change and the need for an assured energy supply. Modern biocatalysis relies to a large extent on the tremendous advances in the so-called omics techniques and the structural elucidation of biomolecules, which have led to synthetic biology and metabolic engineering as new research fields with high application potential for the rational design of enzymes and microbial production strains. In this book, renowned scientists discuss the actual developments in these research fields together with a variety of application-oriented topics.