Methylmercury uptake and degradation by methanotrophs

Lu, Xia, Gu, Wenyu, Zhao, Linduo, Farhan Ul Haque, Muhammad, 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: 22 Jul 2020 01:39
URI: https://ueaeprints.uea.ac.uk/id/eprint/64098
DOI: 10.1126/sciadv.1700041

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