DRAINAGE IMPROVEMENT OF RECYCLED FIBER BACKWATER FOLLOWING ALPHA-AMYLASE BIO-MODIFICATION

The application of a purified alpha-amylase preparation results in sig nificant improvement in the drainage qualities of backwater from a rec ycling paper plant. A crude thermostable alpha-amylase preparation was purified using chromatofocusing to exclude the possible interaction o f contaminating cellulase and xylanase enzymes. The resultant purified alpha-amylase, with a molar mass of 66 000 and isoelectric point of 7 .60, demonstrated an activity of 175.6 units/mg against starch and 182 .5 units/mg against amylopectin. Drainage improvements were demonstrat ed using both the crude and purified forms of the alpha-amylase.