Hydrolysis of Starch by Microorganisms

Other carbohydrates found in foods, such as sucrose and lactose, are hydrolyzed by specific enzymes, -fructosidase (invertase) and -galactosidase (lactase) that are located in the brush border cells of the human small intestine. There are specific permeases in the small intestine wall for transporting D-galac-tose and D-fructose into the blood. 

Many kinds of microorganisms produce a-amylases. The enzymes are extracellular and are secreted into the environment of the organism for hydrolysis of starch. One of the early microbial a-amylases to be studied in some detail was Bacillus amyloliquefaciens a-amylase (formerly known as Bacillus subtilis liquefying a- 

There is an exo-acting bacterial a-amylase, elaborated by Pseudomonas stutzeri, that exclusively produces maltotetraose from starch [10]. The enzyme hydrolyzes maltotetraose units from the nonreducing ends of the starch chains, and, like P-amylase, it will not bypass the a-1 6 branch linkages of amy- 

Pseudomonas amyloderamosa elaborates an isoamylase that specifically hydrolyzes the a-1 - 6 branch linkages of starch [16-20]. Another enzyme that also will hydrolyze the a-1 6 branch linkages of starch is pullulanase, which is elaborated by a strain of A. aerogenes [20]. This enzyme is a hydrolase that specifically hydrolyzes the a-1 6 linkages of the linear polysaccharide, pullulan 

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