Abstract: The present invention provides for the use in the production of cellulolytic and xylanolytic enzymes, particularly xylanase and cellulase, of the microorganism Thermoascus aurantiacus in a culture medium containing at least one of a cellulose or hemicellulose substrate whereby to produce thermostable enzymes, particularly cellulase and xylanase.

Abstract: The separation of xylanases from mixtures thereof with other hemicellulases, particulary cellulase produced by the culturing of hemicellulolytic microorganisms, particularly the fungus Trichoderma harzianum E58 and Trichoderma reesei by ultrafiltration through an ultrafiltration membrane having a low molecular weight cut-off point in the range of about 1,000 to 20,000 daltons to obtain a cellulase rich retentate and xylanase rich ultrafiltrate. The dilute xylanase rich filtrate from the ultrafiltration is concentrated and purified by adsorption and elution from an insoluble matrix, e.g. a cationic exchange resin. The xylanase obtained is suitable for use in the hydrolysis of hemicellulose for which it is selective, particularly in the presence of cellulose and the cellulase rich retentate is suitable for the hydrolysis of cellulose.