Synergistic effect of xylano-pectinolytic enzymes produced by a bacterial isolate in bleaching of plywood industrial waste

Bleach boosting effect of xylano-pectinolytic enzymes produced by Bacillus pumilus AJK was evaluated on plywood veneer soda anthraquinone pulp. Enzyme dose of 6 IU xylanase and 2.4 IU pectinase per g pulp at pH 8.5, temperature 55 degrees C and retention time of 120 min mitigated kappa number of pulp by 9.375%, thus exhibiting remarkable delignification efficiency. The consumption of chlorine and chlorine dioxide diminished by 25% and 23.8% respectively in subsequent bleaching stages with no detrimental effect on the brightness of pulp. Enzyme treated pulp exhibited improved physical properties viz. breaking length, burst factor, tear factor and viscosity. Furthermore, this approach resulted in 16.67% and 18.03% decrease in the BOD and COD values of effluents. This is the first report representing the use of xylano-pectinolytic enzymes, produced concurrently by a cellulase free bacterial strain utilizing agro-residues based production media for bleaching of softwood soda anthraquinone pulp. (C) 2016 Elsevier Ltd. All rights reserved.