Effects of the laccase-mediator system on the handsheet properties of two high kappa kraft pulps

Wong, Ken K. Y.; Anderson, Kathryn B.; Kibblewhite, R. P.

doi:10.1016/s0141-0229(99)00022-8

Cited by 39 publications

(14 citation statements)

References 9 publications

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“…Taking into consideration the fact that the biobleaching experiment was carried out with 100 mU per g of pulp during a 2-h treatment, this result can be compared to the decrease in the kappa number of a softwood kraft pulp treated with 5 U of laccase produced by Trametes versicolor per g of pulp (3) and also with the decrease obtained by using 100 mU of the same laccase after 1 day of incubation (7). Moreover, the reduction in the kappa number obtained with the LMS of S. cyaneus after peroxide extraction was similar to the reduction obtained with a commercial laccase from Novo Nordisk (49). Moreover, the increase in brightness obtained after addition of hydrogen peroxide to LMStreated pulps was significant.…”

Section: Discussionsupporting

confidence: 71%

“…This delignification of kraft pulps has been patented and named the Laccase Mediator System (LMS) (10). This LMS is highly selective and yields pulp with little carbohydrate loss or damage (49). The success achieved at the laboratory and pilotplant scales (11,34) makes this process a desirable system for industrial applications of bleaching of kraft pulps for the manufacture of paper (17).…”

Section: Discussionmentioning

confidence: 99%

“…In particular, laccases from fungi have been found to reduce the kappa number and enhance the bleaching of kraft pulp when they are used in the presence of chemical mediators, such as 2,2Ј-azino-bis(3-ethylbenzothiazoline-6-sulfonate) (ABTS) (8,11,49). In this paper we describe the behavior of the phenol oxidase produced by S. cyaneus CECT 3335 in submerged cultures as a laccase-type behavior, and in this study we also confirmed the usefulness of the purified enzyme in the biobleaching of kraft pulps.…”

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confidence: 99%

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Kraft Pulp Biobleaching and Mediated Oxidation of a Nonphenolic Substrate by Laccase from Streptomyces cyaneus CECT 3335

Arias

Arenas

Rodríguez

et al. 2003

Appl Environ Microbiol

230

127

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A new laccase (EC 1.10.3.2) produced by Streptomyces cyaneus CECT 3335 in liquid media containing soya flour (20 g per liter) was purified to homogeneity. The physicochemical, catalytic, and spectral characteristics of this enzyme, as well as its suitability for biobleaching of eucalyptus kraft pulps, were assessed. The purified laccase had a molecular mass of 75 kDa and an isoelectric point of 5.6, and its optimal pH and temperature were 4.5 and 70°C, respectively. The activity was strongly enhanced in the presence of Cu 2؉ , Mn 2؉ , and Mg 2؉and was completely inhibited by EDTA and sodium azide. The purified laccase exhibited high levels of activity against 2,2-azino-bis(3-ethylbenzothiazoline-6-sulfonate) (ABTS) and 2,6-dimethoxyphenol and no activity against tyrosine. The UV-visible spectrum of the purified laccase was the typical spectrum of the blue laccases, with an absorption peak at 600 nm and a shoulder around 330 to 340 nm. The ability of the purified laccase to oxidize a nonphenolic compound, such as veratryl alcohol, in the presence of ABTS opens up new possibilities for the use of bacterial laccases in the pulp and paper industry. We demonstrated that application of the laccase from S. cyaneus in the presence of ABTS to biobleaching of eucalyptus kraft pulps resulted in a significant decrease in the kappa number (2.3 U) and an important increase in the brightness (2.2%, as determined by the International Standard Organization test) of pulps, showing the suitability of laccases produced by streptomycetes for industrial purposes.Because of their potential for biotechnological applications in areas such as biobleaching, increasing the strength of cellulose fibers, textile dye or stain bleaching, and bioremediation, attention is currently being paid to laccases (2,23,30,43,50). These enzymes are widely distributed in plants and fungi, but until now laccase activity has been reported in only a few bacteria, including Azospirillum lipoferum, Marinomonas mediterranea, Streptomyces griseus, and Bacillus subtilis (1,15,20,22,41,45). A number of roles for laccases in bacterial systems have been suggested and include roles in melanin production and spore coat resistance and involvement in morphogenesis (15,22). In Streptomyces cyaneus, a laccase-type phenol oxidase was found to be produced during growth under solid-substrate fermentation conditions, and it was suggested that this enzyme was involved in the solubilization and mineralization of lignin from wheat straw (5). Further studies demonstrated that this organism could be used to improve the qualities of pulp after 2 weeks of incubation under solid-substrate fermentation conditions (6). However, to date there have been no reports describing the involvement of bacterial laccases in the oxidation of nonphenolic compounds in the presence of mediators. The specific activities of these enzymes with lignin and related substrates have not been examined yet.Laccases are considered some of the most promising enzymes for future industrial applications in the pulp ...

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Section: Discussionsupporting

confidence: 71%

Section: Discussionmentioning

confidence: 99%

mentioning

confidence: 99%

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Kraft Pulp Biobleaching and Mediated Oxidation of a Nonphenolic Substrate by Laccase from Streptomyces cyaneus CECT 3335

Arias

Arenas

Rodríguez

et al. 2003

Appl Environ Microbiol

230

127

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“…However, the use of oxidative enzymes rather than whole organisms does avoid the problem of cellulose hydrolysis. Laccases from fungi have been found to reduce the kappa number and enhance the bleaching of kraft pulp when they are used in the presence of chemical mediators such as 2, 2'-azinobis-(3-ethylbenzthiazoline-6-sulfonate (ABTS) (Wong et al 1999). The more common laccase mediators, 1-hydroxybenzotriazole (1-HBT) and ABTS, have been used by many researchers comparing effects with various laccases.…”

Section: Introductionmentioning

confidence: 99%

Studies on Xylanase and Laccase Enzymatic Prebleaching to Reduce Chlorine-Based Chemicals During Ceh and Ecf Bleaching

Thakur¹,

Jain²,

Mathur³

2012

BioResources

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The biobleaching efficiency of xylanase and laccase enzymes was studied on kraft pulps from wood and nonwood based raw materials employed in the Indian paper industry. Treatment of these pulps with xylanase enzyme could result in improved properties, showing 2.0% ISO gain in pulp brightness and/or reducing the demand of chlorine-based bleach chemicals by up to 15% with simultaneous reduction of 20 to 25% in AOX generation in bleach effluents. Further, mill-scale trial results revealed that enzymatic prebleaching can be successfully employed with xylanases to reach the same bleach boosting efficacy. Laccase bleaching was also studied on hardwood pulp at a pH around 8.0, where most of the pulp mills in India are operating, in contrast to earlier studies on laccase enzyme bleaching, which were conducted at acidic pHs, i.e. 4.0 to 5.0. In case of laccase bleaching, interesting results were found wherein a bleach-boosting effect was observed even at pH 8.0. Further studies carried out with HOBT as mediator in comparison to the commonly used and expensive ABTS laccase mediator system (LMS) resulted in improvement of the bleaching efficiency with reduction in demand of chlorine dioxide by more than 35%. Potential for further reduction was indicated by the brightness gain, when compared with a control using the DE(p)D bleach sequence.

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“…Therefore, laccase modification with HYP is a potential avenue for improving the quality of HYP and their ultimate usage. Mansfield et al (1997), Wong et al (1999Wong et al ( , 2000, and Mansfield (2002) showed that the tensile strength of paper was improved after the laccase treatment of chips processed by steam and a screw extruder. Furthermore, Yamaguchi et al (1994) was successful in finding that after laccase treatment on thermo-mechanical pulp, the tensile strength of paper was greatly improved due to the formation of chemical bonding between pulp lignin and dehydrogenation polymer.…”

Section: Introductionmentioning

confidence: 99%

Structural Analysis of Fast-Growing Aspen Alkaline Peroxide Mechanical Pulp Lignin: A Post-Enzymatic Treatment

et al. 2016

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An enzymatic mild acidic hydrolysis was used to separate and purify residual lignin from alkaline peroxide mechanical pulp (APMP). Using the optimum conditions for the laccase treatment (pH 4.5, temperature 50 °C, lignin consistency of 1%, a reaction time of 60 min, and a laccase dosage of 8 μ/g), oven-dried lignin was treated with laccase and in a laccase mediator system (LMS) to explore the mechanism for laccase and the LMS modification of APMP. The changes of functional groups in lignin were analyzed using nuclear magnetic resonance ( C-NMR spectra revealed that the lignin structure changed significantly with the laccase and the LMS treatments. Meanwhile, GPC demonstrated that laccase without a mediator could lead to the polymerization of lignin, while the LMS could degrade the lignin. Hence, it was concluded that laccase is an attractive enzyme for lignin modification.

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Effects of the laccase-mediator system on the handsheet properties of two high kappa kraft pulps

Cited by 39 publications

References 9 publications

Kraft Pulp Biobleaching and Mediated Oxidation of a Nonphenolic Substrate by Laccase from Streptomyces cyaneus CECT 3335

Kraft Pulp Biobleaching and Mediated Oxidation of a Nonphenolic Substrate by Laccase from Streptomyces cyaneus CECT 3335

Studies on Xylanase and Laccase Enzymatic Prebleaching to Reduce Chlorine-Based Chemicals During Ceh and Ecf Bleaching

Structural Analysis of Fast-Growing Aspen Alkaline Peroxide Mechanical Pulp Lignin: A Post-Enzymatic Treatment

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