Study On Culture Conditions For Xylanase Production By The Solidstate Fementation With Trichoderma

In recent years, as one of the most important enzymes, xylanase has been widely used in food, paper,feed, and textile industries. The xylanase production was investigat-ed with solid fermentation by Trichoderma, and a hiperproducing xylanase strain was screened from the Trichoderma through physical compound mutagenesis. In this thesis we studied the effects of several conditions on xylanase production and enzymatic characteristic of the xylanase.The orginal Trichoderma was treated with ultraviolet light compounded lithium chloride, and one strain with hyperproducing xylanase was selected, its xylanase activity is 730.74U. A five minutes is the best choice to the time of the ultraviolet light.The orthogonal experiments was employed to evaluate the effects of factors on xylanase production, which was carried out under solid-state fermentation process. The optimum constitute of culture medium was bran 4.5 g, corn stalks 5.5 g, corn flour 8%, ammonium sulfate 5%, and solid-liquid ratio 1:1. Xylanase activity reaehed 1156.29 U under the optimized conditions(pH 5.5,28℃,3 d).The xylanase preparation from solid-state fermentation culture were purified by extracting with ammonium sulfate precipitation, and it respectively showed an optimum pH temperature and DNS of pH 4.550℃ and 3 mL. Xylanase was stable below 50℃ and within pH 2.0-8.0.In this thesis, the production of xylanase from Trichoderma was studied in the side of the production and quality, which using low-priced subsidiary agricultural products as original material. It shows that the results of this study has an important meaning in the application of our resource.