Chapter 8 - Amylases

Abstract

Starch is a major storage form for carbohydrates and available carbohydrates comprise 40%–75% of modern dietary energy intake, of which starch is the most abundant. The polymer is composed by linear (amylose) and branched chains of glucose (amylopectin). Starch is hydrolyzed by α-amylases, enzymes existing in multimeric forms. Amylolytic enzymes from extremophile bacteria are similar in their product specificity to the α-amylases of germinating cereals. Pancreatic α-amylase, like other pancreas hydrolases, is an adaptable enzyme. With an increase in starch, the activity of the secreted pancreatic α-amylase is systematically strongly stimulated. Whether the salivary secretion of α-amylase has a relevant function for starch digestion remains to be evaluated more in detail. The opportunities for supplementation of fish feed with exogenous α-amylases with the aim of transforming fish nutrition, particularly that of carnivorous species, in a more ecologically friendly way needs increased research. The feasibility of α-amylase incorporation in the diets will allow an increase in the use of plant-based protein feedstuffs, ensuring aquaculture sustainability.