Fiber surface characterization of old newsprint pulp deinked by combining hemicellulase with laccase-mediator system

Xu, Qingyu; Wang, Y.P.; Qin, Menghua; Fu, Yingjuan; Li, Z.Q.; Zhang, F.S.; Li, J.H.

doi:10.1016/j.biortech.2011.03.051

Cited by 59 publications

(34 citation statements)

References 16 publications

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“…Apart from their synergistic action in the degradation of biopolymers, the specific ligninolytic enzymes, i.e., peroxidases [manganese-dependent peroxidase, MnP (EC 1.11.1.13); lignin peroxidase, LiP (EC 1.11.1.14); or laccase, LAC (EC 1.10.3.2)], are often described in the literature as being very interesting for modern industry and biotechnology (e.g., biotransformation of environmental pollutants, decolorization of textile dye wastes, pulping and bleaching processes, food processing, medicine) [15–18]. According to the available data, LAC and MnP may also act as an important element of the general fungal response to changes in temperature, presence of cadmium, or proxidant treatment [12, 13, 19–22].…”

Section: Introductionmentioning

confidence: 99%

Effective Stimulation of the Biotechnological Potential of the Medicinal White Rot Fungus: Phellinus pini by Menadione-Mediated Oxidative Stress

Jaszek

Kos

Matuszewska

et al. 2014

Appl Biochem Biotechnol

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The effect of menadione (MQ; 2-methyl-1,4-naphtoquinone), a superoxide-generating agent, on the natural biodegradation system in the medicinal white rot fungus Phellinus pini was determined. While measuring the activities of extracellular manganese-dependent peroxidase (MnP) and intracellular chitinase, it was found that the application of MQ (0.75 mM) distinctly stimulated the activities of these enzymes in comparison to the control values (without MQ). Using the capillary electrophoresis (CE) method, an increase in the extracellular oxalic acid (OXA) concentration was detected during the first days after the addition of MQ. It was observed that the rate of intracellular proteolysis at pH 3.5 evidently decreased under oxidative stress conditions. Contrary to these results, the activities of serine proteases at pH 9.5 measured against fluorogenic peptide substrates distinctly increased in stressed cultures. The MQ treatment also caused an evident increase in the catalase (CAT) activity, as well as the levels of superoxide anion radicals (SORs), formaldehyde (FA), and phenolic compounds (PHC) in the experimental cultures. The results obtained confirm that prooxidants may find application as an effective way to stimulate biotechnological production of MnP and chitinase by white rot fungi.

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Section: Introductionmentioning

confidence: 99%

Effective Stimulation of the Biotechnological Potential of the Medicinal White Rot Fungus: Phellinus pini by Menadione-Mediated Oxidative Stress

Jaszek

Kos

Matuszewska

et al. 2014

Appl Biochem Biotechnol

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“…The detachment of ink particles as well as contaminants, with additional chemical modifications induced by laccase enzyme, could enhance brightness and reduce residual ink concentration [9]. There are reports on use of laccase-mediator systems alone and in combination with cellulases and hemicellulases [10], [2]. The laccases used till date for deinking purposes have been obtained from either fungal sources [5] or plants [9].…”

Section: Introductionmentioning

confidence: 99%

Combined Enzymatic and Physical Deinking Methodology for Efficient Eco-Friendly Recycling of Old Newsprint

et al. 2013

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BackgroundThe development in the deinking process has made recycled fiber a major part of the raw material for pulp and paper industry. Enzymes have revolutionized the deinking process obtaining brightness levels surpassing conventional deinking processes. This study explores the deinking efficiencies of bacterial alkalophilic laccase (L) and xylanase (X) enzymes along with physical deinking methods of microwaving (MW) and sonication (S) for recycling of old newsprint (ONP).Methods and ResultsThe operational parameters viz. enzyme dose, pH and treatment time for X and L deinking were optimized statistically using Response Surface Methodology. Laccase did not require any mediator supplementation for deinking. Deinking of ONP pulp with a combination of xylanase and laccase enzymes was investigated, and fiber surface composition and morphological changes were studied using X-ray diffraction, fourier transform infrared spectroscopy and scanning electron microscopy. Compared to the pulp deinked with xylanase (47.9%) or laccase (62.2%) individually, the percentage reduction of effective residual ink concentration (ERIC) was higher for the combined xylanase/laccase-deinked pulp (65.8%). An increase in brightness (21.6%), breaking length (16.5%), burst factor (4.2%) tear factor (6.9%), viscosity (13%) and cellulose crystallinity (10.3%) along with decrease in kappa number (22%) and chemical consumption (50%) were also observed. Surface appeared more fibrillar along with changes in surface functional groups. A combination of physical and enzymatic processes (S-MW-XL) for deinking further improved brightness (28.8%) and decreased ERIC (73.9%) substantially.ConclusionThis is the first report on deinking of ONP with laccase without any mediator supplementation. XL pretreatment resulted in marked improvement in paper quality and a new sequence being reported for deinking (S-MW-XL) will contribute further in decreasing chemical consumption and making the process commercially feasible.

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“…The liquid laccase, Novozym 51003, was supplied by Novozymes A/S (Beijing, China). The laccase activity (1000 U/g) given by the producer was expressed in units (U) with 1 U defined as the amount of enzyme that oxidizes 1 mmol of syringaldazine per minute in a Na-acetate buffer (pH 4.5) at 55 ºC (Xu et al 2011). The methyl syringate (MS), p-hydroxybenzoic acid (HBA), gallic acid (GA), and syringaldehyde (SyA) were analytical grade.…”

Section: Pulp Laccase and Phenolic Compoundsmentioning

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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Fiber surface characterization of old newsprint pulp deinked by combining hemicellulase with laccase-mediator system

Cited by 59 publications

References 16 publications

Effective Stimulation of the Biotechnological Potential of the Medicinal White Rot Fungus: Phellinus pini by Menadione-Mediated Oxidative Stress

Effective Stimulation of the Biotechnological Potential of the Medicinal White Rot Fungus: Phellinus pini by Menadione-Mediated Oxidative Stress

Combined Enzymatic and Physical Deinking Methodology for Efficient Eco-Friendly Recycling of Old Newsprint

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

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