Laccase-Catalyzed Oxidation of Mn
 2+
 in the Presence of Natural Mn
 3+
 Chelators as a Novel Source of Extracellular H
 2
 O
 2
 Production and Its Impact on Manganese Peroxidase

Schlößer, Dietmar; Höfer, Christine

doi:10.1128/aem.68.7.3514-3521.2002

Cited by 185 publications

(123 citation statements)

References 44 publications

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“…That Mn(II) oxidation may lead to the formation of Mn(III) has important environmental implications. Mn(III) is a strong oxidant, present in the photosystem II oxidation of water to oxygen (35) and implicated in the degradation of lignin by fungi (36)(37)(38)(39) and the oxidation of sulfur and nitrogen compounds (40)(41)(42)(43). The trapping studies also show that the enzyme-bound Mn(III) is labile with respect to other ligands.…”

Section: Resultsmentioning

confidence: 99%

Evidence for the presence of Mn(III) intermediates in the bacterial oxidation of Mn(II)

Webb

Dick

Bargar

et al. 2005

Proc. Natl. Acad. Sci. U.S.A.

291

199

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Bacterial oxidation of Mn(II) to Mn(IV) is believed to drive the oxidative segment of the global biogeochemical Mn cycle and regulates the concentration of dissolved Mn(II) in the oceanic water column, where it is a critical nutrient for planktonic primary productivity. Mn(II) oxidizing activity is expressed by numerous phylogenetically diverse bacteria and fungi, suggesting that it plays a fundamental and ubiquitous role in the environment. This important redox system is believed to be driven by an enzyme or enzyme complex involving a multicopper oxidase, although the biochemical mechanism has never been conclusively demonstrated. Here, we show that Mn(II) oxidation by spores of the marine Bacillus sp. strain SG-1 is a result of two sequential one-step electron transfer processes, both requiring the putative multicopper oxidase, MnxG, in which Mn(III) is a transient intermediate. A kinetic model of the oxidation pathway is presented, which shows that the Mn(II) to Mn(III) step is the rate-limiting step. Thus, oxidation of Mn(II) appears to involve a unique multicopper oxidase system capable of the overall two-electron oxidation of its substrate. This enzyme system may serve as a source for environmental Mn(III), a strong oxidant and competitor for siderophorebound Fe(III) in nutrient-limited environments. That metabolically dormant spores catalyze an important biogeochemical process intimately linked to the C, N, Fe, and S cycles requires us to rethink the role of spores in the environment.kinetics ͉ multicopper oxidase ͉ spores ͉ x-ray absorption near-edge spectroscopy

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Section: Resultsmentioning

confidence: 99%

Evidence for the presence of Mn(III) intermediates in the bacterial oxidation of Mn(II)

Webb

Dick

Bargar

et al. 2005

Proc. Natl. Acad. Sci. U.S.A.

291

199

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“…Mn 2+ is considered to be a mediator, inducer or substrate of MnP, but its role in the expression of ligninolytic enzymes by basidiomycetes is controversial. For many of these fungi such as P. chrysosporium and P. ostreatus the presence of this metal in the culture medium is important for the production of MnP (5,25). However, Mn 2+ was not necessary for the production of MnP by P. ostreatus or Bjerkandera sp.…”

Section: Resultsmentioning

confidence: 99%

“…In addition, the presence of Mn 2+ may partially or totally stimulate or inhibit the production of the ligninolytic enzymes such as peroxidase and laccase as described for P. chrysosporium, P. ostreatus and Bjerkandera sp. (2,25).…”

Section: Resultsmentioning

confidence: 99%

Lignolytic enzymes produced by Trametes villosa ccb176 under different culture conditions

Yamanaka¹,

Soares²,

Matheus³

et al. 2008

Braz. J. Microbiol.

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The expression of the enzymatic system produced by basidiomycetous fungi, which is involved in the degradation of xenobiotics, mainly depends on culture conditions, especially of the culture medium composition. Trametes villosa is a strain with a proven biotechnological potential for the degradation of organochlorine compounds and for the decolorization of textile dyes. The influence of glucose concentration, addition of a vegetable oil-surfactant emulsion, nature of the surfactant and the presence of manganese and copper on the growth, pH and production of laccase, total peroxidase and manganese-dependent peroxidase activities were evaluated. In general, acidification of the medium was observed, with the pH reaching a value close to 3.5 within the first days of growth. Laccase was the main activity detected under the different conditions and was produced throughout the culture period of the fungus, irrespective of the growth phase. Supplementation of the medium with vegetable oil emulsified with a surfactant induced manganese-dependent peroxidase activity in T. villosa. Higher specific yields of laccase activity were obtained with the addition of copper.

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“…Most MCOs oxidize organic compounds, especially phenolic compounds, however MCO's have also been shown to oxidize Fe(II) in yeast (Fet3) (Askwith et al 1994), bacteria (Huston et al 2002), and humans (ceruloplasmin) (Lindley et al 1997). In addition, fungal MCOs (laccases) (Hofer and Schlosser 1999;Schlosser and Hofer 2002) have been described that can oxidize Mn(II) to Mn (III). Some MCOs such as ceruloplasmin show a high degree of substrate specificity and others such as laccase possess a more relaxed substrate specificity oxidizing many different substrates including metals and phenolic compounds (Stoj and Kosman 2003) (Solano et al 2001) (Kim et al 2001).…”

Section: Introductionmentioning

confidence: 99%

In vitro studies indicate a quinone is involved in bacterial Mn(II) oxidation

Johnson

Tebo

2007

Arch Microbiol

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Manganese(II)-oxidizing bacteria play an integral role in the cycling of Mn as well as other metals and organics. Prior work with Mn(II)-oxidizing bacteria suggested that Mn(II) oxidation involves a multicopper oxidase, but whether this enzyme directly catalyzes Mn(II) oxidation is unknown. For a clearer understanding of Mn(II) oxidation, we have undertaken biochemical studies in the model marine α-proteobacterium, Erythrobacter sp. strain SD21. The optimum pH for Mn(II)-oxidizing activity was 8.0 with a specific activity of 2.5 nmol × min −1 × mg −1 and a K m = 204 µM. The activity was soluble suggesting a cytoplasmic or periplasmic protein. Mn(III) was an intermediate in the oxidation of Mn(II) and likely the primary product of enzymatic oxidation. The activity was stimulated by pyrroloquinoline quinone (PQQ), NAD + , and calcium but not by copper. In addition, PQQ rescued Pseudomonas putida MnB1 non Mn(II)-oxidizing mutants with insertions in the anthranilate synthase gene. The substrate and product of anthranilate synthase are intermediates in various quinone biosyntheses. Partially purified Mn(II) oxidase was enriched in quinones and had a UV/VIS absorption spectrum similar to a known quinone requiring enzyme but not to multicopper oxidases. These studies suggest that quinones may play an integral role in bacterial Mn(II) oxidation.

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Laccase-Catalyzed Oxidation of Mn ²⁺ in the Presence of Natural Mn ³⁺ Chelators as a Novel Source of Extracellular H ₂ O ₂ Production and Its Impact on Manganese Peroxidase

Cited by 185 publications

References 44 publications

Evidence for the presence of Mn(III) intermediates in the bacterial oxidation of Mn(II)

Evidence for the presence of Mn(III) intermediates in the bacterial oxidation of Mn(II)

Lignolytic enzymes produced by Trametes villosa ccb176 under different culture conditions

In vitro studies indicate a quinone is involved in bacterial Mn(II) oxidation

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Laccase-Catalyzed Oxidation of Mn 2+ in the Presence of Natural Mn 3+ Chelators as a Novel Source of Extracellular H 2 O 2 Production and Its Impact on Manganese Peroxidase

Cited by 185 publications

References 44 publications

Evidence for the presence of Mn(III) intermediates in the bacterial oxidation of Mn(II)

Evidence for the presence of Mn(III) intermediates in the bacterial oxidation of Mn(II)

Lignolytic enzymes produced by Trametes villosa ccb176 under different culture conditions

In vitro studies indicate a quinone is involved in bacterial Mn(II) oxidation

Contact Info

Product

Resources

About

Laccase-Catalyzed Oxidation of Mn ²⁺ in the Presence of Natural Mn ³⁺ Chelators as a Novel Source of Extracellular H ₂ O ₂ Production and Its Impact on Manganese Peroxidase