Microbial amylases: A review

Microbial amylases are enzymes produced by microorganisms to hydrolyze starch. There are three types of microbial amylases: alpha-amylase, beta-amylase and glucoamylase. Each of these amylases has a unique way of acting on starch to yield simple glucose monomers. Microorganisms, plants, and animals are sources of amylases, but much attention is given to microorganisms since the amylases produced by them have greater thermal stability and give rise to different sugar profiles, thus meeting industrial demands. Two major groups of microorganisms play pivotal role in amylase production: bacteria and fungi. Starch is the substrate used in amylase production. Between the two fermentation processes used in amylase production (i.e. submerged fermentation and solid state fermentation), the latter is more advantageous as it saves cost, generates little effluent, and has high volumetric productivity. Microbial amylases are greatly applied in pharmaceutical, food, chemical, paper and distilling industries.