• An enzyme (a naturally occurring catalyst of chemical reactions) found in saliva and gastric juices which breaks down starch (a polysaccharide) into smaller subunits which are further broken down by other enzymes or which can be directly absorbed, usually as glucose, into the blood stream. Strains obtained commercially by fermentation from Aspergillus niger and Bacillus subtilis are used in the manufacture of syrups, in the brewing industry and generally in food manufacturing.