Characteristics of enzyme hydrolysis of cellulose under static condition.

The effect of enzyme loading under static and agitated conditions was investigated. Enzymatic hydrolysis of 10 w/v% de-lignified cellulose slurry such as filter paper, avicel and pulp was conducted under agitated (120 rpm) and static condition, and the enzyme loading ranging from 1.2 to 120 mg-protein/g-dry substrate. Under the agitated condition, the final sugar concentration decreased with the decreasing enzyme loading. Under the static condition, the final sugar concentration was maintained even if the enzyme loading was decreased. The above phenomenon was caused by a rapid precipitation of cellobiohydrolase 2 (CBH2) under the agitated condition, which was not observed under the static condition. The hydrolysis experiments using enzymes containing different ratios of cellobiohydrolase 1 (CBH1) and CBH2 under the static condition suggested that preservation of CBH2 and its synergism with CBH1 is essential for static condition's characteristics, and for efficient hydrolysis of cellulose.