Hydrolysis of Raw Starch by Rhizopus achlamydosporus Immobilized with the Gas Phase Cultivation Method

Abstract

Hydrolysis degrees of raw tapioca starch, raw corn starch and raw potato starch by the mycelia immobilized on non-woven fabrics were 55%, 28% and 19%, respectively. About 60% of the initial amylase activity in the mycelia was released to the reaction mixture at every replacement of reaction mixture, and the residual amylase on the immobilized mycelia wasn't sufficient to hydrolyze raw tapioca starch. Cross-linking of the enzymes resulted in poor hydrolysis of the starch. However, when the 0.1%(w/v) yeast extract was added to a fresh reaction mixture, hydrolysis reaction was successfully repeated until 5th batch in a period of over 150 h.