Aerobic fermentations are an important application field for the use of antifoam agents. They can be distinguished in processes for growth of microorganisms (e.g. baker's yeast production), and the production of various "bio"products (such as antibiotics, enzymes, amino acids and citric acid) by using particular types of bacteria. In aerobic processes, the oxygen supply to the microorganisms is carried out by air blown into the fermenter. The excess air is released and forms foam. Aerobic processes are usually very foam-intensive, since the amount of escaping air is much larger compared to the amount of carbon dioxide in anaerobic processes.