SEPARATION OF ENZYMES PRODUCED BY TRICHODERMA-REESEI WITH HYDROPHOBICULTRAFILTRATION MEMBRANES

The separation of a beta-xylanase by ultrafiltration from a mixture of xylanases and cellulases produced by Trichoderma reesei was investiga ted. The effects of the sizes and the pH dependent charges of the prot eins and the membranes on separation were studied. A stirred cell devi ce with hydrophobic polysulphone membranes of different cut-off values and manufacturers was employed and there were distinct differences in the pore charges of the virgin membranes from different manufacturers . The flux reductions for the membranes were high and the permeate flu xes dropped to the same flux level in spite of the large differences i n the initial water fluxes. beta-Xylanase (isoelectric point 9.0) sele ctivity increased with increasing pH and high selectivity values were obtained with PM30 membranes at pH 7.0.