ISSN 2756-3413
African Journal of Virology Research ISSN 3421-7347 Vol. 10 (3), pp. 001-009, March, 2016. © International Scholars Journals
Full Length Research Paper
Biochemical substitution of fungal xylanases for prebleaching of hardwood kraft pulp
J. Angayarkanni1, M. Palaniswamy2*, B.V. Pradeep2 and K. Swaminathan1
1Department of Biotechnology, Bharathiar University, Coimbatore - 641 046, India.
2Department of Microbiology, Karpagam Arts and Science College, Coimbatore - 641 021, India.
Accepted 15 November, 2015
Abstract
Xylanase enzymes of three fungi, Aspergillus indicus, A. flavus and A. niveus, were purified and characterized. The enzymes are used in the pretreatment of Hardwood kraft pulp prior to conventional alkali extraction and conventional chlorine extraction sequence (EDED process) normally used for bleaching of pulp. In the enzyme pretreated pulp when subjected to alkali extraction process the kappa number was reduced to a maximum of 5.0, 6.2 and 6.8 from 18.60 and the brightness was increased to a maximum of 43.12, 42.20 and 45.19 ISO units, respectively, from 19.83 by xylanases of A. indicus, A. flavus and A. niveus. Whereas, in the enzyme pretreated pulp, when subjected to EDED process, the maximum reduction in kappa number of 6.7, 7.2 and 7.1 and a maximum increase in brightness of 41.28, 41.06 and 41.07 ISO units, respectively, were observed in case of A. indicus, A. flavus and A. niveus.
Key words: Biobleaching, brightness, fungal xylanase, kappa number, kraft pulp, pretreatment.