Application of enzymes in producing bleached pulp from wheat straw.
Crude enzymes produced by different strains were used in the production of bleached wheat straw pulp. Pre-treatment with enzymes from Penicillium A10 and Aspergillus L22 at a xylanase dosage of 4 IU/g prior to pulping decreased pulp kappa number by 6.29% and 12.07% respectively as compared to the control. High cellulase activity in crude enzymes has a negative influence on pulping. Xylanase pre-bleaching reduced chlorine charge by 20-30%, or increased final brightness by approximately 4-5% ISO, and improved the pulp strength properties. Xylanase could substitute for alkali extraction in CEH sequence, and be used for treating chemical-bleached pulp, which resulted in higher strength properties for bleached pulp. Modification of bleached pulp with enzymes of 3 IU/g (on xylanase) increased pulp brightness and breaking length by 3-6% ISO and 160-790 m respectively, and decreased post color number and beating degree of pulp by 29-36% and 2.5-5.5 degrees SR respectively, as compared to the original pulp.
Zhao
Jian
J
State Key Laboratory of Microbial Technology, Shandong University, Jinan, PR China. zhaojian@sdu.edu.cn
Li
Xuezhi
X
Qu
Yinbo
Y
D000383:Agriculture / Q000379:methods*; D001426:Bacterial Proteins / Q000737:chemistry*; D003116:Color; D043364:Endo-1,4-beta Xylanases / Q000737:chemistry*; D007220:Industrial Waste / Q000517:prevention & control*; D035261:Plant Components, Aerial / Q000737:chemistry*; D010936:Plant Extracts / Q000737:chemistry*; D014908:Triticum / Q000737:chemistry*
D001426:Bacterial Proteins; D007220:Industrial Waste; D010936:Plant Extracts; D043364:Endo-1,4-beta Xylanases