The study of the isolation, screening and identification of a xylanase-producing fungus, purification and characterization of xylanase was undertaken in order to produce the enzyme from a cheap source, saw dust, for possible industrial use. Eight fungal strains were isolated and identified from saw-dust out of which Mucor mucedo had the maximum xylanase production and it was selected as the best xylanase-producing strain. Maximal xylanase production occurred on the seventh day of incubation, at a temperature of 55°C and pH of 8.0. Tyrosine and xylose were the most preferred nitrogen and carbon sources respectively. The purification fold and yield obtained after purification were 6.4 and 20% with a specific activity of 14.8 Units/mg protein. The apparent molecular weight of purified xylanase was 30 kDa. The kinetic parameters for purified xylanase with beechwood xylan as substrate were 0.214 ± 0.019 mM and 0.061 ± 0.0012 µmol/ml/min for KM and Vmax respectively. The optimum temperature and pH for the purified xylanase were 45 and 6.0°C respectively. The purified enzyme had no cellulolytic activity. The partially purified enzyme was relatively stable between 35 to 45°C but lost its activity at higher temperature after 2 h incubation. The purified xylanase was stable at pH 6 to 8 after 2 h incubation. The purified xylanase utilized banana peel as substrate than all other agro-industrial waste used. The study concluded that xylanase produced by M. mucedo obtained from saw-dust had properties that made it suitable for industial and biotechnological applications. Key words: Xylanase, Mucor mucedo, purification, biochemical characterization.

Keywords: Xylanase, Mucor mucedo, purification, biochemical characterization.