PT  - JOURNAL ARTICLE
AU  - Lu, Xia
AU  - Gu, Wenyu
AU  - Zhao, Linduo
AU  - Farhan Ul Haque, Muhammad
AU  - DiSpirito, Alan A.
AU  - Semrau, Jeremy D.
AU  - Gu, Baohua
TI  - Methylmercury uptake and degradation by methanotrophs
AID  - 10.1126/sciadv.1700041
DP  - 2017 May 01
TA  - Science Advances
PG  - e1700041
VI  - 3
IP  - 5
4099  - http://advances.sciencemag.org/content/3/5/e1700041.short
4100  - http://advances.sciencemag.org/content/3/5/e1700041.full
SO  - Sci Adv2017 May 01; 3
AB  - 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.