Application of cellulase-free xylano-pectinolytic enzymes from the same bacterial isolate in biobleaching of kraft pulp

Abstract

A synergistic action of xylano-pectinolytic enzymes from the same bacterial isolate Bacillus pumilus was evaluated for the prebleaching of kraft pulp. The enzymatic prebleaching of kraft pulp resulted in 8.5% reduction in kappa number of the pulp, showing remarkable delignification with the enzyme treatment. This approach resulted in 25% reduction in active chlorine consumption in subsequent bleaching stages without any decrease in brightness. Increase in Burst factor (9%), Tear factor (4.6%), Breaking length (4.4%), Double fold number (12.5%), Gurley porosity (4%) and Viscosity (11.8%) of enzyme treated pulp reflected the significant improvement in pulp properties. This is the first report describing the use of xylanase and pectinase produced simultaneously in the same production medium from the same bacterial isolate for effective biobleaching of kraft pulp. Use of this xylano-pectinolytic synergism in paper and pulp industry will ultimately help in making the process not only economically feasible but also eco-friendly.