| Xylan is a major component of hemicellulose in plant cell walls,and it is the second most abundant polysaccharide,next to cellulose,on eatth.Meanwhile,it is one of the abundantly available renewable energy resource.There needs a variety of hydrolytic enzyme to work together to degrate the xylan because of the the diversity and complexity of the structure of nature xylan.Endo-1,4-?-xylanases that cleave the ?-1,4-glycoside bonds of the xylan backbones,which will degrade xylan into xylooligo-saccharide and xylose.Xylanase has a prominent advantage on agriculture,food,medical,energy,papermaking industry and so on.The xylanase from the fermentation broth of Peniicillium decumbens Ju-A10 was separated and purified by ultrafiltration?Q-Sepharose gel anion exchange filtration?SP-Sepharose gel anion exchange filtration and Sephacryl S-200 gel filtration.The purification fold was 17.8,the specific activity was 55.10 U/mg,the yield was 4.02%.SDS-PAGE analysis indicated that the xylanase was electrophoretic purity,and which had molecular weight 47.86 kDa.The optimal reaction temperature of xylanase was 65?;the optimal reaction pH of xylanase was 4.8.The enzyme retained 80 percent activity in the temperature range from 45? to 60 ? and in the pH range of 4.0 to 6.0.Its activity was strongly inhibited by Sn2+?Al3+?Cu2+,and increased dramatically by Ba2+?Na+?Ca2+?Li+?Zn2+?K+.Its Km and Vm were 0.257 mmol/mL and 1.11×10-3 mmol/min respectively. |
PDF Full Text Request