Methylmercury uptake and degradation by methanotrophs

Lu, Xia, Gu, Wenyu, Zhao, Linduo, Farhan Ul Haque, Muhammad ORCID: https://orcid.org/0000-0003-0989-2538, DiSpirito, Alan, Semrau, Jeremy and Gu, Baohua (2017) Methylmercury uptake and degradation by methanotrophs. Science Advances, 3 (5). ISSN 2375-2548

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Abstract

Methylmercury (CH3Hg+) is a potent neurotoxin produced by certain anaerobic microorganisms in natural environments. Although numerous studies have characterized the basis of mercury (Hg) methylation, no studies have examined CH3Hg+ degradation by methanotrophs, despite their ubiquitous presence in the environment. We report that some methanotrophs, such as Methylosinus trichosporium OB3b, can take up and degrade CH3Hg+ rapidly, whereas others, such as Methylococcus capsulatus Bath, can take up but not degrade CH3Hg+. Demethylation by M. trichosporium OB3b increases with increasing CH3Hg+ concentrations but was abolished in mutants deficient in the synthesis of methanobactin, a metal-binding compound used by some methanotrophs, such as M. trichosporium OB3b. Furthermore, addition of methanol (>5 mM) as a competing one-carbon (C1) substrate inhibits demethylation, suggesting that CH3Hg+ degradation by methanotrophs may involve an initial bonding of CH3Hg+ by methanobactin followed by cleavage of the C–Hg bond in CH3Hg+ by the methanol dehydrogenase. This new demethylation pathway by methanotrophs indicates possible broader involvement of C1-metabolizing aerobes in the degradation and cycling of toxic CH3Hg+ in the environment.

Item Type: Article
Faculty \ School: Faculty of Science > School of Environmental Sciences
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Depositing User: Pure Connector
Date Deposited: 13 Jul 2017 05:05
Last Modified: 21 Oct 2022 14:35
URI: https://ueaeprints.uea.ac.uk/id/eprint/64098
DOI: 10.1126/sciadv.1700041

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