Abstract: Preparation of xylanase by Thermoascus aurantiacus on corn cob residue was studied.Optimal fermentation parameters were:corn cob residue 4%;rotating speed 180 r/min;initial pH value of medium 4.8%;culture temperature 45℃;C/N of medium 7.1.Xylanase activity in the broth reached 900 U/mL.Optimal temperature and pH value for the xylanase reaction were 75℃ and 4.8,respectively.The enzyme preparation was thermo stable and had a good application potential.

Key words: Thermoascus aurantiacus, xylanase, corn cob residue, liquid fermentation