Book excerpt: Protein engineering has proved to be one of the more fruitful technological approaches in biotechnology, being both very powerful and able to generate valuable intellectual property. This book aims to present examples in which the application of protein engineering has successfully solved problems arising in industrial biotechnology. There is a section on its use to enhance purification of recombinant proteins. The use of protein engineering to modify the activity or the stability of industrial enzymes from lipases to proteases, from carboxypeptidases to glucanases and glucosidases, and from pectin modifying enzymes to enzymes able to degrade recalcitrant compounds is extensively covered. It is shown how areas as diverse as agrofood technology, fine chemistry, detergents, bioremediation and biosensors receive significant contributions from protein and solvent engineering. The application of protein engineering to health care is also covered, from the development of new vaccines to new potential therapeutic proteins. A specific notation is given to protein engineering in the development of target molecules for drug discovery. International in scope, the many contributions are drawn from academia and industry. The text should be of interest to students and researchers in industrial biotechnology as well as to everybody interested in basic research in protein structure, molecular genetics, bio-organic chemistry, biochemistry, agrobiotechnology, pharmaceutical sciences and medicine.