ENZYME-ACTIVITY RECOVERY FROM SECONDARY FIBER TREATED WITH CELLULASE AND XYLANASE

One of the major problems with implementing biotechnical processes in the recycled paper industry, such as enzyme-enhanced deinking and enzy matic enhancement of pulp drainage properties, is the cost of commerci al enzyme preparations. Thus, several factorial studies were performed to determine if enzyme activity can be successfully removed from simu lated recycled fiber (once-dried, bleached hardwood and softwood kraft fiber) treated with low concentrations (0.2% or 2.0% on oven-dry fibe r) of cellulase or xylanase. Enzyme activity recovery was accomplished by washing treated fiber with dilute NaOH in combination with a low c oncentration of the nonionic surfactant Tween 80 under a variety of mi ld conditions. Various cellulase activities, i.e., endoglucanase, exog lucanase, and filter paper, can be effectively recovered depending on the washing conditions, the cellulase charge, and the fiber type. Xyla nase activity was effectively recovered from softwood, but not hardwoo d. The results suggest that enzyme activity recovery may be a possible means of decreasing the operating costs for biotechnical processes in the paper industry.