Modification in the properties of paper by using cellulase-free xylanase in biobleaching of wheat straw pulp produced from alkalophilic Cellulosimicrobium cellulans CKMX1

Alkalophilic Cellulosimicrobium cellulans CKMX1 isolated from mushroom compost is actinomycetes that produce industrially important and environmentally safer thermostable cellulase-free xylanase, which is used in the pulp and paper industry as alternatives to the use of toxic chlorinated compounds. Strain CKMX1 was previously characterized by metabolic fingerprinting, whole-cell fatty acids methyl ester analysis and 16S rDNA and found to be Cellulosimicrobium cellulans CKMX1. Crude enzyme (1027.65 U/g DBP) produced by C. cellulans CKMX1 having optimum pH and temperature of 8.0 and 60°C in solid state fermentation of apple pomace was used in the production of bleached wheat straw pulp. Pretreatment with xylanase at a dose of 5 U/g after pulping decreased pulp kappa points by 1.4, respectively as compared to the control. Xylanase pre-bleaching reduced chlorine charge by 12.5%, or gain in final brightness points by approximately 1.42% ISO, and improved the pulp strength properties in 5 U/g enzymatic treatments. Xylanase could substitute for alkali extraction in C-Ep-D sequence, and be used for treating chemical-bleached pulp, which resulted in higher strength properties of bleached pulp. Modification of bleached pulp with enzyme of 5 U/g increased pulp whiteness and breaking length by 1.03% and 60 m respectively, and decreased tear factor of pulp by 7.29%, and increase in bulk weight by 3.99% respectively, as compared to the original pulp. Reducing sugars and UV-absorbing lignin-derived compound values were considerably higher in xylanase treated samples. C cellulans CKMX1 has a potential application in the pulp and paper industries.The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author