title: Studying the effects of laccase treatment in a softwood dissolving pulp: cellulose reactivity and crystallinity.
abstract: An enzymatic biobleaching sequence (LVAQPO) using a laccase from Trametes villosa in combination with violuric acid (VA) and then followed by a pressurized hydrogen peroxide treatment (PO) was developed and found to give high bleaching properties and meet dissolving pulp requirements: high brightness, low content of hemicellulose, satisfactory pulp reactivity, no significant cellulose degradation manifested by α-cellulose and HPLC, and brightness stability against moist heat ageing. The incorporation of a laccase-mediator system (LMS) to bleach sulphite pulps can be a good alternative to traditional bleaching processes since thermogravimetric analysis (TGA) showed that the laccase treatment prevented the adverse effect of hydrogen peroxide on fibre surface as observed during a conventional hydrogen peroxide bleaching treatment (PO). Although VA exhibited the best results in terms of bleaching properties, the performance of natural mediators, such as p-coumaric acid and syringaldehyde, was discussed in relation to changes in cellulose surface detected by TGA.
authors.affiliation: CELBIOTECH_Paper Engineering Research Group, Universitat Politècnica de CatalunyaBarcelonaTech, 08222 Terrassa, Spain. Electronic address: elisabet.quintana@etp.upc.edu.
authors.forename: Elisabet
authors.initials: E
authors.lastname: Quintana
authors.affiliation: CELBIOTECH_Paper Engineering Research Group, Universitat Politècnica de CatalunyaBarcelonaTech, 08222 Terrassa, Spain.
authors.forename: Cristina
authors.initials: C
authors.lastname: Valls
authors.affiliation: Chemical Engineering, Physical Chemistry and Organic Chemistry Department, University of Huelva (ceiA3), Spain.
authors.forename: Agustín G
authors.initials: AG
authors.lastname: Barneto
authors.affiliation: CELBIOTECH_Paper Engineering Research Group, Universitat Politècnica de CatalunyaBarcelonaTech, 08222 Terrassa, Spain.
authors.forename: Teresa
authors.initials: T
authors.lastname: Vidal
authors.affiliation: Chemical Engineering, Physical Chemistry and Organic Chemistry Department, University of Huelva (ceiA3), Spain.
authors.forename: José
authors.initials: J
authors.lastname: Ariza
authors.affiliation: CELBIOTECH_Paper Engineering Research Group, Universitat Politècnica de CatalunyaBarcelonaTech, 08222 Terrassa, Spain. Electronic address: roncero@etp.upc.edu.
authors.forename: M Blanca
authors.initials: MB
authors.lastname: Roncero
mesh_terms: D002482:Cellulose / Q000737:chemistry*; D003116:Color; D003460:Crystallization; D042845:Laccase / Q000494:pharmacology*; D008031:Lignin / Q000302:isolation & purification; D010209:Paper; D028222:Picea / Q000737:chemistry; D028223:Pinus / Q000737:chemistry; D012995:Solubility; D013696:Temperature; D055454:Trametes / Q000201:enzymology*; D014783:Viscosity; D014934:Wood / Q000187:drug effects*
chemical_list: D002482:Cellulose; D008031:Lignin; D042845:Laccase
keywords: 1-Hydroxybenzotriazole (PubChem CID 75771); Alkali solubility; Diethylenetriaminepentaacetic acid (PubChem CID 3053); Dissolving pulp; Syringaldehyde (PubChem CID 8655); Thermogravimetric analysis (TGA); Violuric acid; Violuric acid (PubChem CID 6399005); p-Coumaric acid (PubChem CID 637542); α-Cellulose