Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:1.10.3.2 (laccase)
 4,656 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The aim of this work was to obtain a LMS pre-treatment applicable to industrial TCF bleaching. Kraft pulp from Eucalyptus globulus was treated at 40 degrees C/pH 3 and 60 degrees C/pH 5 for 1h using an extracellular fluid enriched in laccase produced by Pycnoporus sanguineus and acetosyringone as mediator (HBT was used as a control mediator) (L). Alkaline extraction (E) and hydrogen peroxide (P) stages were then assayed. The LEP alternative was an efficient sequence to bleach kraft pulp since the enzymatic pre-treatment boosted the subsequent chemical bleaching. The best L pre-treatment was obtained with laccase-acetosyringone at 40 degrees C/pH 3. It reduces kappa number and hexenuronic acids, increases pulp viscosity, lowers hydrogen peroxide consumption down to an 87.4% (94.0% without L) and enhances brightness up to a 59% ISO (51% ISO without L).
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PMID:Kraft pulp biobleaching using an extracellular enzymatic fluid produced by Pycnoporus sanguineus. 1985 61

Laccase and xylanase were tested for their suitability for biobleaching of soda-anthraquinone pulp from oil palm empty fruit bunches (EFB). An enzymatic stage with xylanase (X) and/or laccase (L) was incorporated before the alkaline extraction stage (E) and the hydrogen peroxide bleaching stage (P). Compared with controls, the LEP sequence resulted in an improvement of optical properties (brightness and colorimetric properties) and a reduction of the kappa number. When xylanase and laccase were used jointly, no improvement was detected, however, when the xylanase application preceded the laccase stage, the beneficial effects of laccase were boosted. Thus, the final XLEP bleached pulp showed a kappa number of 5.4 and a brightness of 60.5% ISO, although the hydrogen peroxide consumption increased (77.0% vs. 64.5% and 73.8% for EP and LEP respectively). Finally, after subjecting the bleached pulps to accelerated ageing, the best optical properties were observed in the XLEP pulp.
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PMID:Biobleaching of pulp from oil palm empty fruit bunches with laccase and xylanase. 2234 93