Effects of Lipase and Xylanase Pretreatment on the Structure and Pulping Properties of Wheat Straw

Abstract

Based on the reduction of environmental pollution, a biological enzyme assisted alkali-oxygen pulping method was explored to improve the delignification efficiency and fiber accessibility of wheat straw and improve the properties of wheat straw pulp. In this paper, lipase and xylanase were used to pretreat wheat straw and the effects of different enzyme types and enzyme dosage on the microstructure and pulp properties of wheat straw were investigated and experimented. The results showed that the lipase can remove fat and wax on the surface of wheat straw, while xylanase degraded the hemicellulose components, such as xylan, of wheat straw fiber, destroyed the structure of the lignin-carbohydrate complex, increasing lignin removal as a result and enhancing the impregnating, diffusion and penetration of alkali. Compared with wheat straw without enzyme pretreatment, the skeleton of wheat straw pretreated by enzyme became looser, the internal cavity appeared and the wall cavity became thin and transparent. The fines decreased obviously and the length of fibers increased. After combined pretreatment with lipase (15 U·g−1) and xylanase (15 U·g−1), the pulping performance of wheat straw was improved and the tensile index (97.37 N·m·g−1), brightness (40.9% ISO) and yield (58.10%) of the pulp increased by 12.9%, 19.9% and 9.9%, respectively. It can be seen that enzyme pretreatment is a green and effective approach to improving the alkali-oxygen pulping performance of wheat straw.

Study on the Characterization of Physical, Mechanical, and Mildew Resistance Properties of Enzymatically Treated Bamboo Fiber-Reinforced Polypropylene Composites

“…Secondly, although lipase, pectinase, and amylase do not affect lignin degradation, these enzymes can indirectly promote lignin removal by carrying away some Consequently, the components on the surface of the bamboo fibers undergo some degree of degradation or removal following modifications with various biological enzymes. Specifically, xylanase primarily degrades the xylan in bamboo fibers [28], lipase eliminates certain fat and lipids [29], laccase degrades some lignin and lipids [30], pectinase removes some pectin [31], hemicellulase removes some hemicellulose [32], and amylase eliminates some starch and other polysaccharide substances [33]. Thus, after treatment with biological enzymes, the surface structure of the bamboo fiber was damaged, making the surface of the bamboo fiber rough, which is conducive to its better combination with the plastic matrix.…”

Combined alkali impregnation and poly dimethyl diallyl ammonium chloride-assisted cellulase absorption for high-efficiency pretreatment of wheat straw

“…In recent years, the enzyme-assisted pre-treatment methods have been developed to mitigate the chemical resistance of raw materials, reduce energy consumption, and enhance pulp performance [13][14][15][16][17][18][19][20]. The application of cellulase can reduce the production of ne bers, thereby enhancing the water ltration e ciency of pulp and the physical properties of paper during the papermaking process [21,22].…”