Starch conversion by soluble and immobilized α‐amylase

B. subtilis α‐amylase was immobilized on cyanogen bromide activated carboxymethyl cellulose. The conversion of wheat starchwas carried out at 72°C in a stirred tank by soluble and immobilized α‐amylase. The initial reaction rate with immobilized α‐amylase was lower than with the soluble enzyme, but after 1 hr immobilized α‐amylase produced a higher quantity of reducing sugars than the soluble enzyme. The action pattern of immobilized α‐amylase was different from that of the soluble enzyme: immobilized α‐amylase produced relatively more glucose and maltose, except at the beginning of conversion. Immobilized α‐ readily hydrolyze G 6 . The starch conversion by immobilized α‐amylase was not diffusion controlled at a stirring rate of 100‐300 rpm.