CHARACTERIZATION OF A XYLANASE FROM AUREOBASIDIUM-PULLULANS

A xylanase from the imperfect fungus Aureobasidium pullulans ATCC 4202 3 was purified 38-fold to homogeneity. The molecular weight of the pur ified enzyme was similar to 21 kD. The pH optimum of the enzyme was fr om 3.0-4.5, while its temperature optimum was 35 degrees C. This xylan ase was highly specific for xylan as a substrate. The K-m for birchwoo d xylan at 30 degrees C was 2.93 mg/ml, while its V-max was 866 mu mol xylose/min/mg protein. The enzyme was inhibited by a number of metal ions, with ZnCl2 or CoCl2 being the most effective inhibitors.