Structure, functionality and tuning up of laccases for lignocellulose and other industrial applications

Sitarz, Anna Katarzyna; Mikkelsen, Jørn Dalgaard; Meyer, Anne S.

doi:10.3109/07388551.2014.949617

Cited by 75 publications

(88 citation statements)

References 108 publications

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“…Due to the lower redox potentials of laccases (≤0.8 V) compared to ligninolytic peroxidases (>1 V) (Wong, 2009; Rivera-Hoyos et al, 2013; Pollegioni et al, 2015; Sitarz et al, 2016), laccases are originally thought to be able to oxidize only the phenolic lignin moiety, with the majority of lignin being non-phenolic and with higher redox potentials. Low-molecular-weight redox mediators are used to expand the laccase substrate range or increase the reaction rate, especially for substrates with higher redox potentials or too large to fit in the enzyme's active site.…”

Section: Laccase Mediatorsmentioning

confidence: 99%

“…Since laccases have wide substrate ranges and use only oxygen as the final electron receptor, they have widespread applications in various industries, such as textile, food, biofuel, organic synthesis, bioremediation, paper and pulp, pharmaceutical, and cosmetic industries (Arora and Sharma, 2010; Majeau et al, 2010; Osma et al, 2010; Kudanga et al, 2011; Jeon et al, 2012; Betancor et al, 2013; Kudanga and Roes-Hill, 2014; Mogharabi and Faramarzi, 2014; Viswanath et al, 2014; Pezzella et al, 2015; Mate and Alcalde, 2016; Senthivelan et al, 2016; Sitarz et al, 2016; Upadhyay et al, 2016). In fact, a few laccase products are already commercially available for food, paper, textile, and other industries (Osma et al, 2010; Rodríguez-Couto, 2012).…”

Section: Introductionmentioning

confidence: 99%

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Laccases: Production, Expression Regulation, and Applications in Pharmaceutical Biodegradation

et al. 2017

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Laccases are a family of copper-containing oxidases with important applications in bioremediation and other various industrial and biotechnological areas. There have been over two dozen reviews on laccases since 2010 covering various aspects of this group of versatile enzymes, from their occurrence, biochemical properties, and expression to immobilization and applications. This review is not intended to be all-encompassing; instead, we highlighted some of the latest developments in basic and applied laccase research with an emphasis on laccase-mediated bioremediation of pharmaceuticals, especially antibiotics. Pharmaceuticals are a broad class of emerging organic contaminants that are recalcitrant and prevalent. The recent surge in the relevant literature justifies a short review on the topic. Since low laccase yields in natural and genetically modified hosts constitute a bottleneck to industrial-scale applications, we also accentuated a genus of laccase-producing white-rot fungi, Cerrena, and included a discussion with regards to regulation of laccase expression.

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Section: Laccase Mediatorsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Laccases: Production, Expression Regulation, and Applications in Pharmaceutical Biodegradation

et al. 2017

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“…Among these enzymes laccases (benzenediol:oxygen oxidoreductase, EC 1.10.3.2) uses molecular oxygen to catalyse oxidation of phenolic substrates similar to those found in lignin subunits. A laccase catalysed oxidation cycle involves oxidation of four moles of phenolic substrate and simultaneous reduction of one mole of O2 to H2O [10,11].…”

Section: Introductionmentioning

confidence: 99%

Direct rate assessment of laccase catalysed radical formation in lignin by electron paramagnetic resonance spectroscopy

Munk

Andersen

Meyer

2017

Enzyme and Microbial Technology

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Highlights Time course EPR measurement of direct radical formation by fungal laccases on genuine lignin samples  Assessment of enzyme kinetic rates of radical formation in lignin by two fungal laccases  Identification of different radical formation patterns by a low and high redox potential laccase  Demonstration of different laccase rates on different types of lignin substrates Abstract Laccases (EC 1.10.3.2) catalyse removal of an electron and a proton from phenolic hydroxyl groups, including phenolic hydroxyls in lignins, to form phenoxy radicals during reduction of O2. We employed electron paramagnetic resonance spectroscopy (EPR) for real time measurement of such catalytic radical 2 formation activity on three types of lignin (two types of organosolv lignin, and a lignin rich residue from wheat straw hydrolysis) brought about by two different fungal laccases, derived from Trametes versicolor (Tv) and Myceliophthora thermophila (Mt), respectively. Laccase addition to suspensions of the individual lignin samples produced immediate time and enzyme dose dependent increases in intensity in the EPR signal with g-values in the range 2.0047-2.0050 allowing a direct quantitative monitoring of the radical formation and thus allowed laccase enzyme kinetics assessment on lignin. The experimental data verified that the laccases acted upon the insoluble lignin substrates in the suspensions. When the action on the lignin substrates of the two laccases were compared on equal enzyme dosage levels (by activity units on syringaldazine) the Mt laccase exerted a significantly faster radical formation than the Tv laccase on all three types of lignin substrates. When comparing the equal laccase dose rates on the three lignin substrates the enzymatic radical formation rate on the wheat straw lignin residue was consistently higher than that of the organosolv lignins. The pH-temperature optimum for the radical formation rate in organosolv lignin was determined by response surface methodology to pH 4.8, 33°C and pH 5.8, 33°C for the Tv laccase and the Mt laccase, respectively. The results verify direct radical formation action of fungal laccases on lignin without addition of mediators and the EPR methodology provides a new type of enzyme assay of laccases on lignin.

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“…Laccase, a multi-copper oxidase, catalyzes the monoelectronic oxidation of a broad spectrum of substrates (Sitarz et al 2014;Jones and Solomon 2015) and thus an environmentally interesting enzyme well known for its action on both phenolic and non-phenolic, and on highly recalcitrant compounds. Extensive research has been dedicated to the fungal laccase in the last decades due to its biotechnological and potential environmental applications (Rodríguez Couto and Toca Herrera 2006;Majeau et al 2010;Viswanath et al 2014).…”

Section: Introductionmentioning

confidence: 99%

Laccase encapsulation in chitosan nanoparticles enhances the protein stability against microbial degradation

Koyani

Vázquez-Duhalt

2016

Environ Sci Pollut Res

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A novel concept with the result of enzyme stabilization against microbial degradation in real bioremediation processes was developed through the encapsulation of laccase in chitosan nanoparticles. Besides of abundant information on laccase-chitosan conjugates, we report the laccase encapsulation into nanoparticles based in chitosan. The chitosan-tripolyphosphate technique was applied for the production of morphologically homogeneous enzymatic nanoparticles, with high enzyme encapsulation efficiency, small asymmetric sizes (from 40 to 90 nm), and rough surfaces. Contrary to macroscopic immobilized enzymes, temperature and pH activity profiles of nano-sized laccase were similar to those of free enzyme. The substrate affinity constant (K M) of nano-encapsulated laccase was similar to these from free enzyme, while its activity rate constant (k cat) represented 60 % of these obtained with free enzyme. Importantly, stability of nano-encapsulated laccase against microbial degradation in soil, compost, and wastewater was significantly increased. After 24 h exposure to wastewater from a treatment plant, the laccase activity of the nanoparticles was 82.8 % of initial activity, compared with only 7.8 % retained activity for free enzyme. After 36 h incubation in compost extract, the laccase nanoparticles showed 72.4 % of the initial activity, while the free enzyme was almost completely inactivated. Finally, after 84 h incubation in soil extract, the nanoparticles and free preparations showed 57.9 and 17.3 % of the initial activity, respectively. Thus, the nanoencapsulation of enzymes able to transform pollutants is an alternative to improve the operational lifetime of enzymes in real environmental applications.

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Structure, functionality and tuning up of laccases for lignocellulose and other industrial applications

Cited by 75 publications

References 108 publications

Laccases: Production, Expression Regulation, and Applications in Pharmaceutical Biodegradation

Laccases: Production, Expression Regulation, and Applications in Pharmaceutical Biodegradation

Direct rate assessment of laccase catalysed radical formation in lignin by electron paramagnetic resonance spectroscopy

Laccase encapsulation in chitosan nanoparticles enhances the protein stability against microbial degradation

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