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Assessing the use of xylanase and laccases in biobleaching stages of a TCF sequence for flax pulp
Author(s) -
Fillat Amanda,
Roncero M. Blanca,
Vidal Teresa
Publication year - 2011
Publication title -
journal of chemical technology and biotechnology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.64
H-Index - 117
eISSN - 1097-4660
pISSN - 0268-2575
DOI - 10.1002/jctb.2662
Subject(s) - kappa number , laccase , pulp (tooth) , xylanase , chemistry , pulp and paper industry , effluent , syringaldehyde , food science , lignin , kraft process , organic chemistry , waste management , enzyme , kraft paper , medicine , pathology , engineering
BACKGROUND: In this study, two different laccases were used in combination with various mediators as biobleaching agents in a TCF sequence for flax fibre and pulp. Thus, non‐commercial laccase from Pycnoporus cinnabarinus (PcL) was used with the synthetic mediator violuric acid (VA) or the natural mediator syringaldehyde (SA), and commercial laccase from Myceliophthora thermophila (MtL) was used with the natural mediator methyl syringate (MS). Each laccase–mediator treatment was used in the following TCF bleaching sequence: LQPo (Q denoting a chelating stage and Po a pressurized alkaline peroxide treatment). Also, a xylanase pretreatment was carried out for first time here to assess its effect on flax fibre. Pulp (kappa number, viscosity and brightness) and effluent properties (COD, colour, residual activity and toxicity) were determined after each bleaching stage. The hexenuronic acid (HexA) content of the pulp was also determined to assess its integrity. RESULTS: The best L stage was PcL + VA, which provided a final brightness and kappa number of 81% ISO and 1.3, respectively. Using a xylanase pretreatment was found to efficiently remove HexA and enhance delignification by laccase (final kappa number 0.7). CONCLUSIONS: These results warrant upscaling any of these biobleaching sequences for flax pulp as they provide environmentally sustainable flax fibre with a high cellulose content and brightness above 80% ISO. Copyright © 2011 Society of Chemical Industry