Production of Glucoamylase by Solid-State Fermentation Using Urethane Foam Carrier as a Semi-Solid Medium

By using urethane foam carrier (UFC) as a semi-solid medium, and impregnating it with a liquid medium, we have studied an effective solid-state system for cultivation of Aspergillus oryzae. This system can control the initial substrate concentration and medium composition as well as the feed rate of medium, and enzyme can be separated simply from the culture system. It was elucidated that maximum production activity of glucoamylase was obtained under batch culture conditions where the initial amount of sugar was around 35, 000 mg/l -bulk volume and the initial moisture content was from 78 to 80%. By feeding the soluble starch medium intermittently, it was found that glucoamylase could be produced semicontinuously with high production activity when moisture content was maintained around 85% during the repeated -batch culture period.