The Research Of Xylanase Hydrolysing Chitosan

So many researches indicate that,there are 37 enzymes being able to hydrolysing chitosan non-specifically,such as cellulase,papain,hemicellulase,lipase,lysozyme.Xylanase is one kind of hemicellulase,there is no research report on hydrolysing chitosan specifically.This paper is important meaning in clarifying the mechanism of degradating chitosan of non-specifical enzyme,and is important in enzyme producing low-molecular-weight chitosan with enzyme.This research first had carried on the comparison to the xylanase and other four kinds of enzymes hydrolysing chitosan's activity.Result indicates:the xylanase is highest active to hydrolysing chitosan. The xylanase's optimum condition of hydrolysing chitosan is:pH4.75, temperature 60℃,E/S 15%.When the substrate's viscosity has no influence to the enzyme vigor display, the hydrolysis process of xylanase to chitosan is fit to the Michaelis-Menten equation,and in that,Vmax=15.314μmol/min·L,Km=3.5g/L.That is say:when the substrate's concentration is enough low,the xylanase is single-substract enzymatic catalysis reaction, and there is only one bind site in a enzyme molecular,and there is only one complex compound in the reaction course.Furthermore,used Sepharose the CL-6B gel chromatography to determine the hydrolysate's molecular weight distribution,and made a comparison between xylanase's hydrolysate and other four enzymes hydrolysate's molecular weight distribution.The result indicates that,hydrolysate's molecular weight distribution which hydrolysed by xylanase after 6hours concentrates on 8613Da ; hydrolysate's molecular weight distribution of the inactive enzyme concentrates on 18462Da;after half hour's hydrolysis,the other four kind enzymes'hydrolate's molecular weight distribution condition as follows:the cellulase liquid from aspergillus niger on 11943Da,the same as xylanase;the cellulase powder from blue mold on 13317Da;the cellulase powder from aspergillus niger on 12611 Da.Finally,carried on the simple separation purification to the commercial xylanase liquid.In the purification process,the enzyme's activity has a little loss.The chitosanase activity losed 3000U,xylanase activity losed 5200U.Used SDS-PAGE and HPLC analysing the xylanase's component,result indicates:the xylanase consists of these molecular weight component 55000 Da,34000 Da,11000 Da;Which one kind or some kind of components has the effect to chitosan hydrolisis, is not clear now,and this needs a further research.