Biobleaching of pulp with dioxygen in the laccase-mediator system — reaction mechanisms for degradation of residual lignin

Balakshin, Mikhail; Capanema, Ewellyn A.; Chen, Chen-Loung; Gratzl, Josef S.; Kirkman, Adrianna G.; Gracz, Hanna

doi:10.1016/s1381-1177(00)00225-3

Cited by 39 publications

(39 citation statements)

References 20 publications

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“…However, this process is not fully developed due to the availability of efficient and stable in industrial conditions enzymes, the high cost and potential toxicity of the mediators and the long reaction times involved [2,3]. Moreover, oxidative enzymes have scarcely been used to bleach non-wood pulp [4][5][6][7][8]; also, most kinetic studies on their effects have focused on the action of laccase mediator systems (LMS) in reactions with lignin model compounds for short times [9,10].…”

Section: Introductionmentioning

confidence: 99%

“…Previous studies on the influence of the treatment time with a LMS on the extent of pulp delignification on reactions with lignin model compounds or eucalyptus kraft pulp revealed that the process involves two distinct stages [10,11,12]. In the initial stage, the pulp is rapidly delignified to a limiting kappa number similarly as in ozone-based treatments [13,14]; in the final stage, delignification is slow but the oxygen uptake continues to be high, which suggests the presence of active chemical species in the system not reacting with residual lignin, but rather interacting with lignin fragments via side reactions [9,10].…”

Section: Introductionmentioning

confidence: 99%

“…In the initial stage, the pulp is rapidly delignified to a limiting kappa number similarly as in ozone-based treatments [13,14]; in the final stage, delignification is slow but the oxygen uptake continues to be high, which suggests the presence of active chemical species in the system not reacting with residual lignin, but rather interacting with lignin fragments via side reactions [9,10].…”

Section: Introductionmentioning

confidence: 99%

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Biobleaching of high quality pulps with laccase mediator system: Influence of treatment time and oxygen supply

Fillat

Roncero

2009

Biochemical Engineering Journal

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In this study we examined the influence of the treatment time and addition of oxygen on the efficiency of a laccase mediator system (L) applied to flax pulp at atmospheric pressure. The redox potential and the dissolved oxygen concentration during L tests are measured. After L stage, an alkaline extraction (E) is carried out. The pulp properties (kappa number, brightness and viscosity) and the effluents properties (color and COD) were measured in order to evaluate the environmental impact of this enzymatic treatment.The biotreatment involves two distinct stages in both L and LE sequences; in the beginning the pulp exhibits a fast delignification and a slow viscosity decrease that is followed by slow delignification in the second. Pulp brightness changed differently during L stage and LE sequence.Initially brightness after the L stage decreased with respect to the initial pulp; then, it increased rapidly and eventually leveled off. After the LE sequence, brightness increased rapidly in the beginning and more gradually afterwards. The results show that supplying the medium with oxygen and increasing the oxygen concentration in it, influence the kinetics of the process.Based on CIE L*a*b* color coordinates study, the enzyme treatment not only removes lignin, but also alters the structure of the pulp by causing the formation of chromophoric groups giving color.Such groups are removed in an E stage.

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Biobleaching of high quality pulps with laccase mediator system: Influence of treatment time and oxygen supply

Fillat

Roncero

2009

Biochemical Engineering Journal

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“…Therefore, it has more opportunity to react with the surface lignin and penetrate fiber pores. The phenolic moieties may participate in not only the oxidative degradation but also dehydrogenative polymerization reactions of residual lignin in the pulp by laccase (Balakshin et al 2001). Tables 1 and 3 showed that the surface lignin coverage and kappa number of the L/HBA-treated fibers had little change.…”

Section: Xps Analysismentioning

confidence: 99%

Laccase-Catalyzed Fiber Functionalization with Different Phenolic Compounds for Enhancing Pulp Strength

Liu¹,

Qin²,

Li³

2013

BioResources

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Chemo-enzymatic functionalization offers an innovative approach to produce paper and board products with enhanced performance. Unbleached softwood kraft pulps were functionalized by laccase with methyl syringate(MS), p-hydroxybenzoic acid(HBA), gallic acid(GA), and syringaldehyde(SyA). The wet strength of fibers treated with MS and SyA increased by 57.9% and 31.9%, respectively. The dry strength of fibers treated with HBA, GA, and SyA increased from about 64 N·m/g to 68 N·m/g. The opacity of MS-treated fibers was the highest, and the surface lignin coverage increased. The kappa number and surface lignin of HBAtreated fibers changed little; however, the total carboxyl group significantly increased. The participation of phenolic compounds enhanced the reactivity of fibers to laccase in varying degree. However, the reactivity of phenols to laccase did not show a direct relation to the paper strength. All treatments with phenols decreased the brightness and the curl index of fibers. The syringyl-type phenols with hydrophobic groups (OCH 3 ) were shown to be effective for improving the pulp wet strength. The compounds with carboxyl groups enhanced the pulp dry-strength. The observed pulp strength improvement could be attributed to the formation of covalent bonding via radical coupling, the attachment of the functional group, increased bonding area, and fiber entanglement.

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“…This is because laccase is an environmentally friendly enzyme, which works in the presence of oxygen and produces water as its only byproduct (Kalia et al 2014). In addition, laccase can be used for many technical processes (Call and Mücke 1997;Couto and Toca-Herrera 2006;Riva 2006;Mikolasch and Schauer 2009), such as bio-bleaching in the pulp and paper industry (Balakshin et al 2001;Zhang et al 2007), decreasing the refining energy (Mansfield 2002), deinking of waste paper pulp (Welt and Dinus 1998;Ibarra et al 2012), lignin degradation (Rico et al 2014), and dyeing in the textile industry (Galante and Formantici 2003).…”

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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Biobleaching of pulp with dioxygen in the laccase-mediator system — reaction mechanisms for degradation of residual lignin

Cited by 39 publications

References 20 publications

Biobleaching of high quality pulps with laccase mediator system: Influence of treatment time and oxygen supply

Biobleaching of high quality pulps with laccase mediator system: Influence of treatment time and oxygen supply

Laccase-Catalyzed Fiber Functionalization with Different Phenolic Compounds for Enhancing Pulp Strength

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

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