Application of Bleaching Reed Pulp by Xylanase-Producing Alkalophilic Bacillius

Abstract

The reeds are the reeds of the Gramineae Lo bamboo family and they are major non-wood papermaking raw materials. Based on the importance of the reed in the papermaking, many useful discussions have been carried out about its pulping and bleaching processes (Shatalov et al.,2001).Finnish scholars reported a pulp by the xylanase treatment could reduce the segment of chloride to chlorine consumption of 25% for the first time in 1986 (Viikari et al., 1986),and it was soon put into industrial production after then. Xylanase can reduce the amount of chemical additives by improving the bleach ability of the pulp, thereby reducing environmental pollution and reduce production costs, and increase the brightness of the paper (Anatoly et al., 2007).Although many scholars have done a lot of research in biobleaching, and have made some progress, but most of the selection of microorganisms are fungi and neutrophilic bacteria, the production of xylanase is usually in the pH 5 - 7, 40-50°C which often leads to maximal activity, thus lack of compatibility with the conventional chemical pulping process. In recent years, the thermal stability of alkaline xylanase has been paid much attention (Shatalov et al.,2003). Alkalophilic bacteria secreted extracellular enzyme with heat, basophilic characteristics, can be used directly to the biopulping pretreatment and bleaching of wood and non wood raw materials. The recent study on organic solventbased pulping of giant reed showed that competitive papermaking fibres could be produced using this advanced pulping technology (Shatalov and Pereira, 2001). The amount of enzyme not only directly affects the size of pulp hardness, degree of polymerization and brightness, but also was the basis for investigating the economic of dealing with enzyme.The results of alkaline bacteria xylanase bleaching ramie fiber have been reported previously (Zheng et al., 2000). In this study, the xylanase of alkalophilic Bacillus is used in reed pulp bleaching pretreatment, and the physical and chemical properties of the enzyme to deal with the reed pulp are analyzed.