BER launches Environmental System Science Program. Visit our new website under construction!

U.S. Department of Energy Office of Biological and Environmental Research

BER Research Highlights


Dual Role for Organic Matter in Mercury Cycling and Toxicity
Published: February 07, 2011
Posted: March 17, 2011

Mercury from worldwide industrialization is a widely recognized global pollutant. Concern over mercury is due to the bioaccumulation of the highly toxic methylmercury. Methylmercury is created by microbes through the conversion of inorganic mercury, Hg(II), under anaerobic conditions, such as those found in stream sediments. However, dissolved organic matter (DOM), which is ubiquitous in soils and aquatic sediments, forms strong complexes with Hg(II), influencing the microbial production of methylmercury. A research team from Oak Ridge National Laboratory (ORNL) has found that low concentrations of DOM reduce Hg(II), and that high concentrations of DOM forms complexes with Hg. The authors propose that the dual nature of DOM activity is due to the redox state of sulfur in DOM and the DOM:Hg ratio which affect the transformation of Hg and the potential microbial production of toxic methylmercury. These findings provide greater understanding of the potential transformations of Hg that are occurring not only in the mercury-contaminated East Fork Poplar Creek stream sediments on the Y-12 complex in Oak Ridge but in the sediments of many other mercury-contaminated streams worldwide.

Reference: Gu, B., Y. Bian, C. L. Miller, W. Dong, X. Jiang, and L. Liang. 2011. "Mercury Reduction and Complexation by Natural Organic Matter in Anoxic Environments," Proceedings of the National Academy of Sciences USA DOI:10.1073/pnas.1008747108.

Contact: Paul E. Bayer, SC-23.1, (301) 903-5324
Topic Areas:

  • Research Area: Subsurface Biogeochemical Research
  • Research Area: Microbes and Communities

Division: SC-33.1 Earth and Environmental Sciences Division, BER

 

BER supports basic research and scientific user facilities to advance DOE missions in energy and environment. More about BER

Recent Highlights

Jan 11, 2022
No Honor Among Copper Thieves
Findings provide a novel means to manipulate methanotrophs for a variety of environmental and in [more...]

Dec 06, 2021
New Genome Editing Tools Can Edit Within Microbial Communities
Two new technologies allow scientists to edit specific species and genes within complex laborato [more...]

Oct 27, 2021
Fungal Recyclers: Fungi Reuse Fire-Altered Organic Matter
Degrading pyrogenic (fire-affected) organic matter is an important ecosystem function of fungi i [more...]

Oct 19, 2021
Microbes Offer a Glimpse into the Future of Climate Change
Scientists identify key features in microbes that predict how warming affects carbon dioxide emi [more...]

Aug 25, 2021
Assessing the Production Cost and Carbon Footprint of a Promising Aviation Biofuel
Biomass-derived DMCO has the potential to serve as a low-carbon, high-performance jet fuel blend [more...]

List all highlights (possible long download time)