Catalytic efficiency of natural and synthetic compounds used as laccase-mediators in oxidising veratryl alcohol and a kraft lignin, estimated by electrochemical analysis

González‐Arzola, Katiuska; Arévalo, M.C.; Falcón, M. A.

doi:10.1016/j.electacta.2008.10.059

Cited by 54 publications

(26 citation statements)

References 48 publications

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“…Namely, redox mediators can be oxidized by the laccase and then be reduced back to their original species by accepting electrons during the oxidation of target organic compounds. Such a laccase-mediator system is widely present in nature for laccase to oxidize a wide range of recalcitrant organic compounds (Arzola, Arevalo, & Falcon, 2009). In general, there are three types of mechanisms for redox mediators to enhance laccase biocatalysis: Ionic oxidation (IO), hydrogen atom transfer (HAT), and electron transfer (ET; Astolfi et al, 2005), as illustrated in Figure 2a.…”

Section: Effect Of Redox Mediators In Enhancing the Sdl-catalyzed Amentioning

confidence: 99%

Biocatalytic properties of cell surface display laccase for degradation of emerging contaminant acetaminophen in water reclamation

Chen

Wei

2019

Biotech & Bioengineering

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The surface display laccase (SDL) biocatalyst, where the enzyme laccase is displayed on the surface of biological cells through synthetic biology, provides a new opportunity to develop sustainable technologies for removal of emerging contaminants from wastewater. This study vigorously characterized biocatalytic properties of the SDL in comparison to free laccase in removing emerging contaminant acetaminophen (APAP), with the aim to understand the effect of surface display on enzyme functionality and identify the strategy to overcome the potential limitation. The SDL could effectively remove APAP. Adding redox mediators substantially improved the removal efficiency. The Michaelis–Menten kinetic analysis showed that the redox mediator 2,2‐azinobis‐3‐ethylbenzothiazoline‐6‐sulfonate could overcome the limitation of APAP accessing the active site of laccase in the SDL biocatalyst. The APAP removal rate catalyzed by the SDL in real secondary wastewater effluent was higher than that in acetate buffer; comprehensive enzyme kinetic analysis provided clear evidence that there were redox mediating compounds in the wastewater. Analysis of transformation products revealed that surface display did not change laccase functionality in terms of APAP transformation mechanism. In addition, the SDL retained 88% of the initial activity after six repeated APAP biotransformation reactions. Results from this study provide a scientific basis for developing and implementing SDL as an innovative biocatalytic material for contaminant treatment applications.

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Section: Effect Of Redox Mediators In Enhancing the Sdl-catalyzed Amentioning

confidence: 99%

Biocatalytic properties of cell surface display laccase for degradation of emerging contaminant acetaminophen in water reclamation

Chen

Wei

2019

Biotech & Bioengineering

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“…As shown in Table 4, some differences in the HexA removal were also produced depending on the mediator: approximately 10% of HexA removal was produced with HBT and VA (in comparison with the C L ); however, HexA was not significantly affected by SA and AS. The lower redox potential of these mediators may explain these results: Epa = +589 and +575 mV of SA and AS, respectively, vs. +870 and +720 mV of HBT and VA, respectively (González Arzola et al 2009;Aracri et al 2013). Moreover, SA and AS may easier attach to pulp fibers in the presence of HexA (Cadena et al 2011).…”

Section: Effects Of Natural and Synthetic Mediators On Eucalyptus Pulpmentioning

confidence: 83%

Enzymatic strategies to improve removal of hexenuronic acids and lignin from cellulosic fibers

2013

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Different enzymatic strategies were applied to improve lignin and hexenuronic acid (HexA) removal. Three laccases (L) with different redox potentials were applied in combination with 1-hydroxybenzotriazole or methyl syringate to softwood sulfite and hardwood kraft fibers. The enzymes with a high-redox potential from Pycnoporus cinnabarinus and Trametes villosa were found to be the most efficient. The bleaching efficiency was not significantly influenced by the presence or absence of HexA in the different types of lignocellulosic fibers.Subsequently, the lignin or HexA removal in the presence of different mediators was evaluated in eucalyptus fibers with the T. villosa laccase (TvL). Natural mediators removed only lignin, whereas the combinations of TvL with synthetic mediators removed both HexA and lignin. The mediator violuric acid (VA) was the most efficient as judged by the properties of fiber and effluent. A xylanase pretreatment stage was found to boost the access of the LVA system to HexA without affecting lignin in the pulpPostprint (published version

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“…The oxidation peak current of mediators is enhanced in the presence of a substrate (Ueda et al 1987;Bourbonnais et al 1998;Gorgy et al 1998;Kishioka and Yamada 2005;González Arzola et al 2009). Figure 2b-d display the CVs of NHPI in the presence of compound 1G (2.0 eq of NHPI) and 2,6-lutidine (5.0 eq of NHPI) in 0.1 M LiClO 4 /CH 3 CN at various scan rate.…”

Section: Cyclic Voltammetry (Cv) Of Nhpimentioning

confidence: 97%

“…The mediators which are proposed for LMS -such as ABTS, HBT, VA, N-hydroxyphtalimide (NHPI), 2,29,6,69-tetramethylpiperidine-N-oxyl (TEMPO) (Galli and Gentili 2004;Morozova et al 2007;González Arzola et al 2009) -are also candidates for EMS, although EMS and LMS gave different results with the same mediator (Rochefort et al 2002a). According to Fabbrini et al (2002), the LMS oxidation of 1-(3,4-dimethoxyphenyl)-2,2-dimethyl-1-propanol with HBT and NHPI afforded only the corresponding a-ketone in 30% and 50% yields, respectively.…”

Section: Introductionmentioning

confidence: 95%

Studies on electro-oxidation of lignin and lignin model compounds. Part 2: N-Hydroxyphthalimide (NHPI)-mediated indirect electro-oxidation of non-phenolic lignin model compounds

et al. 2012

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The N-hydroxyphthalimide (NHPI)-mediated indirect electro-oxidation of non-phenolic lignin model compounds has been investigated for selective C a -carbonylation of lignin. A cyclic voltammogram of NHPI in 0.1 M LiClO 4 /CH 3 CN with 2,6-lutidine interpreted that NHPI can act as a mediator in the indicated process in the range 0.5-0.8 V vs. Ag/Ag q . The corresponding C a -carbonyl compounds was obtained in high yields (85-97%) in the case of the monomer 1-(4-ethoxy-3-methoxyphenyl) ethanol in 0.1 M LiClO 4 /CH 3 CN or 0.1 M LiClO 4 /(CH 3 CN/H 2 Os7/3) with a small amount of 2,6-lutidine at 0.7 V vs. Ag/Ag q . The processing of the dimeric lignin model compound (4-ethoxy-3-methoxyphenylglycerol-b-guaiacyl ether) also gave the corresponding C a -carbonyl compound in high yield (88-92%). The reaction proceeds through hydrogen atom transfer in the NHPI-mediated electro-oxidation. On the other hand, the direct electrooxidation and indirect electro-oxidation mediated by ABTS w2,29-azinobis(3-ethylbenzothiazoline-6-sulfonate)x of the dimeric compound preferentially gave the corresponding C a -C b cleavage product in low or moderate yields (5-40%). The conclusion is that NHPI is an excellent mediator for selective C a -carbonylation of non-phenolic b-O-4 structures in lignin in electronic mediator system.

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Catalytic efficiency of natural and synthetic compounds used as laccase-mediators in oxidising veratryl alcohol and a kraft lignin, estimated by electrochemical analysis

Cited by 54 publications

References 48 publications

Biocatalytic properties of cell surface display laccase for degradation of emerging contaminant acetaminophen in water reclamation

Biocatalytic properties of cell surface display laccase for degradation of emerging contaminant acetaminophen in water reclamation

Enzymatic strategies to improve removal of hexenuronic acids and lignin from cellulosic fibers

Studies on electro-oxidation of lignin and lignin model compounds. Part 2: N-Hydroxyphthalimide (NHPI)-mediated indirect electro-oxidation of non-phenolic lignin model compounds

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