Earlier this year, a multidisciplinary team of researchers at Oak Ridge National Laboratory discovered two key genes that are essential for microbes to convert oxidized mercury to methylmercury, a neurotoxin that can penetrate skin and at high doses affect brain and muscle tissue, causing paralysis and brain damage.
ORNL researchers are learning more about the microbial processes that convert elemental mercury into methylmercury.
The discovery of how methylmercury is formed answered a question that had stumped scientists for decades, and the findings published this week build on that breakthrough.
Most mercury researchers have believed that microbes could not convert elemental mercury -- which is volatile and relatively inert -- into methylmercury. Instead of becoming more toxic, they reasoned that elemental mercury would bubble out of water and dissipate. That offered a solution for oxidized mercury, which dissolves in water. By converting oxidized mercury into elemental mercury, they hoped to eliminate the threat of methylmercury contamination in water systems.
ORNL’s study and a parallel study reported by Rutgers University, however, suggest that elemental mercury is also susceptible to bacterial manipulation, a finding that makes environmental cleanup more challenging.
“Communities of microorganisms can work together in environments that lack oxygen to convert elemental mercury to methylmercury,” study leader Baohua Gu said. “Some bacteria remove electrons from elemental mercury to create oxidized mercury, while others add a methyl group to produce methylmercury.”
Mercury is a toxin that spreads around the globe mainly through the burning of coal, other industrial uses, and natural processes such as volcanic eruptions, and various forms of mercury are widely found in sediments and water. Methylmercury bioaccumulates in aquatic food chains, especially in large fish.
The fight against mercury pollution involves scientists with expertise in chemistry, computational biology, microbiology, neutron science, biochemistry and bacterial genetics. Other ORNL efforts are focusing on when, where and why bacteria are producing methylmercury.
“Our research allows us to understand generally where and how bacteria might produce methylmercury so that we can target those areas in the future,” said ORNL’s Liyuan Liang, a co-author and director of the DOE-funded mercury research program. “We are trying to understand the process of microbial mercury methylation. Once we understand the process, we can begin to form solutions to combat mercury pollution.”
This research was funded by the DOE Office of Science. ORNL co-authors of the paper, titled "Oxidation and Methylation of Dissolved Elemental Mercury by Anaerobic Bacteria," are Haiyan Hu, Hui Lin, Wang Zheng, Stephen Tomanicek, Alexander Johs, Dwayne Elias, Liyuan Liang and Baohua Gu. Another co-author, Xinbin Feng, is from the State Key Laboratory of Environmental Geochemistry of China.
UT-Battelle manages ORNL for DOE's Office of Science. The Office of Science is the single largest supporter of basic research in the physical sciences in the United States and is working to address some of the most pressing challenges of our time. For more information, please visit http://science.energy.gov/.
Jennifer Brouner | EurekAlert!
Early organic carbon got deep burial in mantle
25.04.2017 | Rice University
New atlas provides highest-resolution imagery of the Polar Regions seafloor
25.04.2017 | British Antarctic Survey
More and more automobile companies are focusing on body parts made of carbon fiber reinforced plastics (CFRP). However, manufacturing and repair costs must be further reduced in order to make CFRP more economical in use. Together with the Volkswagen AG and five other partners in the project HolQueSt 3D, the Laser Zentrum Hannover e.V. (LZH) has developed laser processes for the automatic trimming, drilling and repair of three-dimensional components.
Automated manufacturing processes are the basis for ultimately establishing the series production of CFRP components. In the project HolQueSt 3D, the LZH has...
Reflecting the structure of composites found in nature and the ancient world, researchers at the University of Illinois at Urbana-Champaign have synthesized thin carbon nanotube (CNT) textiles that exhibit both high electrical conductivity and a level of toughness that is about fifty times higher than copper films, currently used in electronics.
"The structural robustness of thin metal films has significant importance for the reliable operation of smart skin and flexible electronics including...
The nearby, giant radio galaxy M87 hosts a supermassive black hole (BH) and is well-known for its bright jet dominating the spectrum over ten orders of magnitude in frequency. Due to its proximity, jet prominence, and the large black hole mass, M87 is the best laboratory for investigating the formation, acceleration, and collimation of relativistic jets. A research team led by Silke Britzen from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has found strong indication for turbulent processes connecting the accretion disk and the jet of that galaxy providing insights into the longstanding problem of the origin of astrophysical jets.
Supermassive black holes form some of the most enigmatic phenomena in astrophysics. Their enormous energy output is supposed to be generated by the...
The probability to find a certain number of photons inside a laser pulse usually corresponds to a classical distribution of independent events, the so-called...
Microprocessors based on atomically thin materials hold the promise of the evolution of traditional processors as well as new applications in the field of flexible electronics. Now, a TU Wien research team led by Thomas Müller has made a breakthrough in this field as part of an ongoing research project.
Two-dimensional materials, or 2D materials for short, are extremely versatile, although – or often more precisely because – they are made up of just one or a...
20.04.2017 | Event News
18.04.2017 | Event News
03.04.2017 | Event News
25.04.2017 | Earth Sciences
25.04.2017 | Life Sciences
25.04.2017 | Earth Sciences