caa a22 4500 378867792 CHVBK 20180305123402.0 cr unu---uuuuu 161128e20030820xx s 000 0 eng 10.1515/HF.2003.076 doi (NATIONALLICENCE)gruyter-10.1515/HF.2003.076 Optimization of a Laccase-Mediator Stage for TCF Bleaching of Flax Pulp [Elektronische Daten] [O. García, S. Camarero, J. F. Colom, Á. T. Martínez, M. J. Martínez, R. Monje, T. Vidal] Flax pulp obtained by anthraquinone-soda pulping, resulting in a kappa number of 11.1, a viscosity of 950 ml/g and 36.7% ISO brightness, was bleached in a totally chlorine-free sequence using the enzyme laccase from the fungus Pycnoporus cinnabarinus and 1-hydroxybenzotriazole (HBT) as redox mediator (stage L), followed by a hydrogen peroxide stage (P). The laccase treatment was optimized using a three-variable sequential statistical plan over the following ranges: 1-20 U/g o.d.p. (oven-dried pulp) laccase dose, 0.5-7.5% o.d.p. HBT dose and 1-24 h reaction time. The influence of these variables on several pulp properties after the P stage of the LP sequence was examined. The models defined from the results obtained predicted variations in ISO brightness, viscosity and kappa number of 57.6-74.8%,590-955 ml/g and 0-6.2, respectively. The variables most strongly influencing these pulp properties were found to be the reaction time and the enzyme dose. A compromise was adopted as regards the operating conditions in order to ensure optimum results. The study was completed by conducting a biobleaching assay in a pressurized reactor (590 kPa) to assess the effect of oxygen pressure. The high pressure level resulted in improved pulp properties by the laccase-mediator system. Copyright © 2003 by Walter de Gruyter GmbH & Co. KG Timber & wood processing nationallicence Biotechnology nationallicence Materials science nationallicence García O. aut Camarero S. aut Colom J. F. aut Martínez Á. T. aut Martínez M. J. aut Monje R. aut Vidal T. aut Holzforschung Walter de Gruyter 57/5(2003-08-20), 513-519 0018-3830 57:5<513 2003 57 hfsg https://doi.org/10.1515/HF.2003.076 text/html Onlinezugriff via DOI 1 research article jats NATIONALLICENCE 856 40 https://doi.org/10.1515/HF.2003.076 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- García O. aut NATIONALLICENCE 700 1- Camarero S. aut NATIONALLICENCE 700 1- Colom J. F. aut NATIONALLICENCE 700 1- Martínez Á. T. aut NATIONALLICENCE 700 1- Martínez M. J. aut NATIONALLICENCE 700 1- Monje R. aut NATIONALLICENCE 700 1- Vidal T. aut NATIONALLICENCE 773 0- Holzforschung Walter de Gruyter 57/5(2003-08-20), 513-519 0018-3830 57:5<513 2003 57 hfsg CC0 http://creativecommons.org/publicdomain/zero/1.0 nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-gruyter