EFFECT OF RECOMBINANT XYLANASE B(XYN B) FROM HYPERTHERMOPHILIC THERMOTOGA MARITIMA ON TOTALLY CHLORINE FREE(TCF) OF BAMBOO KRAFT PULP

摘要

The recombinant xylanase B (XynB) from hyperthermophilicThermotoga maritima was highly specific activity towards xylans and very low activity towards carboxymethyl-cellulose in previous study. The optimum temperature of XynB is 90 □ and it still retained a high activity at 100 □. Besides, it is very stable during the pH range of 6.1 to 11.1. The effect of pretreatment condition such as time, temperature, pH to bamboo kraft pulps was studied. The application of xynB in TCF bleaching of bamboo kraft pulps enables the fully bleached pulps with high brightness (84%ISO) and viscosity (above800mL/g). XynB pretreatment can reduce the quantity of H_2O_2 needed in subsequent bleaching stages. SEM (scanning electron microscopy) performed after xynB treatment showed notable changes on fibre surface.