Delignification of eucalypt kraft pulp with manganese-substituted polyoxometalate assisted by fungal versatile peroxidase.
Oxidation of the manganese-substituted polyoxometalate [SiW(11)Mn(II)(H(2)O)O(39)](6-) (SiW(11)Mn(II)) to [SiW(11)Mn(III)(H(2)O)O(39)](5-) (SiW(11)Mn(III)), one of the most selective polyoxometalates for the kraft pulp delignification, by versatile peroxidase (VP) was studied. First, SiW(11)Mn(II) was demonstrated to be quickly oxidized by VP at room temperature in the presence of H(2)O(2) (K(m)=6.4+/-0.7 mM and k(cat)=47+/-2s(-1)). Second, the filtrate from eucalypt pulp delignification containing reduced polyoxometalate was treated with VP/H(2)O(2), and 95-100% reoxidation was attained. In this way, it was possible to reuse the liquor from a first SiW(11)Mn(III) stage for further delignification, in a sequence constituted by two polyoxometalate stages, and a short intermediate step consisting of the addition of VP/H(2)O(2) to the filtrate for SiW(11)Mn(II) reoxidation. When the first ClO(2) stage of a conventional bleaching sequence was substituted by the two-stage delignification with polyoxometalate (assisted by VP) a 50% saving in ClO(2) was obtained for similar mechanical strength of the final pulp.
Marques
Gisela
G
Instituto de Recursos Naturales y Agrobiología de Sevilla, CSIC, P.O. Box 1052, E-41080 Seville, Spain.
Gamelas
José A F
JA
Ruiz-Dueñas
Francisco J
FJ
del Rio
José C
JC
Evtuguin
Dmitry V
DV
Martínez
Angel T
AT
Gutiérrez
Ana
A
D005052:Eucalyptus / Q000737:chemistry*; D008031:Lignin / Q000737:chemistry* / Q000302:isolation & purification*; D008345:Manganese / Q000737:chemistry*; D010209:Paper; D009195:Peroxidase / Q000737:chemistry*; D020076:Pleurotus / Q000201:enzymology*; D017973:Tungsten Compounds / Q000737:chemistry*; D000099294:Polyoxometalates
D008031:Lignin; D008345:Manganese; D009195:Peroxidase; D017973:Tungsten Compounds; C102296:polyoxometalate I; D000099294:Polyoxometalates