Study on Enzyme Activity of Xylanase from Mutated Aspergillus Niger and Enzymolysis of Xylan in Paddy Hull

The strain producing high-yield xylanase with low enzymatic activity of cellulase was screened through mutation of Aspergillus niger by UV-ray.The enzymatic activity of xylanase from mutated Aspergillus niger was analyzed.The xylanase stability to temperature and pH value was determined.The effects of xylan concentration and xylanase dosage on enzymolysis were discussed.The best mutation conditions of Aspergillus niger were as follows:UV power 40 W,distance 28 cm,irradiation time 2.5 min.The optimum conditions for produced xylanase were as follows:temperature 50℃,pH value 4.2.The results showed that xylan concentration had no effect on enzymolysis,xylanase dosage affected enzymolysis obviously,the enzymolysis efficiency was the best with 30 g·L-1 xylan concentration,2%~5% xylanase dosage.