Removal of Lipophilic Extractives from Paper Pulp by Laccase and Lignin-Derived Phenols as Natural Mediators
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- 作者：Ana Gutié ; rrez ; Jorge Rencoret ; David Ibarra ; Setefilla Molina ; Susana Camarero ; Javier Romero ; José ; C. Del Rí ; o ; Á ; ngel T. Martí ; nez
- 刊名：Environmental Science & Technology
- 出版年：2007
- 出版时间：June 1, 2007
- 年：2007
- 卷：41
- 期：11
- 页码：4124 - 4129
- 全文大小：148K
- 年卷期：v.41,no.11(June 1, 2007)
- ISSN：1520-5851
文摘
In this paper, we show for the first time that lignin-derived phenols can act as laccase mediators for theremoval of lipophilic compounds from paper pulp. Thesenatural mediators represent an alternative to syntheticmediators, such as 1-hydroxybenzotriazole (HBT), that causesome economic and environmental concerns. Unbleachedkraft pulp from eucalypt wood, which contained freeand conjugated sterols responsible for pitch deposition inthe manufacture of totally chlorine free paper, wastreated with a fungal laccase in the presence ofsyringaldehyde, acetosyringone, and p-coumaric acid asmediators. The composition of lipophilic extractives in thepulps after the enzymatic treatment followed by a hydrogenperoxide stage was analyzed by gas chromatography andgas chromatography/mass spectrometry. The enzymatictreatment using syringaldehyde as laccase mediator causedthe highest removal (over 90%) of free and conjugatedsitosterol, similar to that attained with HBT, followed byacetosyringone (over 60% removal), whereas p-coumaricacid was barely effective. Moreover, recalcitrant oxidizedsteroids surviving laccase-HBT treatment could beremoved when using these natural mediators. Pulpbrightness was also improved (from 57% to 66% ISObrightness) by the laccase treatment in the presence ofthe above phenols followed by the peroxide stage due tothe simultaneous removal of lignin.