Starch hydrolysis microbial amylases

Renneberg et al. (1984) described a microbial hybrid sensor for a-amylase assay. A membrane with coimmobilized B. subtilis cells and glucoamylase was attached to an O2 electrode. Starch and the a-amylase sample were added to the measuring cell. Low-molecular weight products of the a-amylase-catalyzed starch hydrolysis diffuse into the biocatalytic membrane where they are cleaved by glucoamylase to glucose, which is assimilated by the bacteria. The sensor responded linearly to a-amylase up to 1.5 U/ml. 

For starch hydrolysis by microbial a-amylase, the following activation energies, which lie between the limits stated in section 2.5.4.2, were derived from e. g. the Arrhenius diagram (Fig. 2.35) ... 

P. Mischnick, Specificity of microbial a-amylase and amyloglucosidase hydrolysis of methyl amyloses, Starch, 53 (2001) 110-120. 

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-... 

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