Methylmercury, a potent human neurotoxin, appears in the environment when certain naturally occurring bacteria transform inorganic mercury into its more toxic cousin. Few bacterial species are capable of this conversion, and exactly how the transformation takes place has been a matter of debate for decades.
“What is not known are the genes or the proteins that allow these bacteria to mediate the transformation,” said ORNL’s Steven Brown, who led a research team to sequence the genome of a bacterium in the Desulfovibrio genus that is capable of methylating mercury.
The new genome, sequenced at the California-based DOE Joint Genome Institute (JGI) and published in the Journal of Bacteriology, lays the foundation for future research to examine the little understood mechanisms behind the production of methylmercury.
Desulfovibrio desulfuricans strain ND132 is an organism that thrives in sediments and soils without oxygen – the places in lakes, streams and wetlands where mercury contamination is converted to methylmercury. It is representative of a group of organisms that “breathe” sulfate instead of oxygen and are largely responsible for mercury methylation in nature.
“This is the first Desulfovibrio genome that will methylate mercury that’s been published,” Brown said. “Now that we have this resource, we can take a comparative approach and look at what is different between the bacteria that can methylate mercury and those that are unable to.”
The introduction of mercury into the environment primarily stems from its use in industrial processes and from the burning of fossil fuels. Although industry and regulators have worked to minimize the release of mercury, there is a legacy of mercury pollution in aquatic environments worldwide. Understanding the fundamental science behind the production of methylmercury could eventually help mitigate and reduce the impacts of mercury pollution.
“Mercury is a global contaminant of concern,” Brown said. “We hope that some of the lessons we learn from these studies will be applicable to many sites. If we can identify the genes involved in mercury methylation, we hope to go to the local environment and understand more about the function and the ecology of the organisms and their gene products that mediate this transformation.”
The study was published as “Genome Sequence of the Mercury Methylating Strain Desulfovibrio desulfuricans ND132.” Collaborators included researchers from ORNL, the Smithsonian Environmental Research Center, the University of Missouri and Lawrence Berkeley National Laboratory’s JGI.
The research was supported by DOE’s Office of Science.
ORNL is managed by UT-Battelle for the Department of Energy's Office of Science.
Morgan McCorkle | Newswise Science News
Two Group A Streptococcus genes linked to 'flesh-eating' bacterial infections
25.09.2017 | University of Maryland
Rainbow colors reveal cell history: Uncovering β-cell heterogeneity
22.09.2017 | DFG-Forschungszentrum für Regenerative Therapien TU Dresden
At the productronica trade fair in Munich this November, the Fraunhofer Institute for Laser Technology ILT will be presenting Laser-Based Tape-Automated Bonding, LaserTAB for short. The experts from Aachen will be demonstrating how new battery cells and power electronics can be micro-welded more efficiently and precisely than ever before thanks to new optics and robot support.
Fraunhofer ILT from Aachen relies on a clever combination of robotics and a laser scanner with new optics as well as process monitoring, which it has developed...
Plants and algae use the enzyme Rubisco to fix carbon dioxide, removing it from the atmosphere and converting it into biomass. Algae have figured out a way to increase the efficiency of carbon fixation. They gather most of their Rubisco into a ball-shaped microcompartment called the pyrenoid, which they flood with a high local concentration of carbon dioxide. A team of scientists at Princeton University, the Carnegie Institution for Science, Stanford University and the Max Plank Institute of Biochemistry have unravelled the mysteries of how the pyrenoid is assembled. These insights can help to engineer crops that remove more carbon dioxide from the atmosphere while producing more food.
A warming planet
Our brains house extremely complex neuronal circuits, whose detailed structures are still largely unknown. This is especially true for the so-called cerebral cortex of mammals, where among other things vision, thoughts or spatial orientation are being computed. Here the rules by which nerve cells are connected to each other are only partly understood. A team of scientists around Moritz Helmstaedter at the Frankfiurt Max Planck Institute for Brain Research and Helene Schmidt (Humboldt University in Berlin) have now discovered a surprisingly precise nerve cell connectivity pattern in the part of the cerebral cortex that is responsible for orienting the individual animal or human in space.
The researchers report online in Nature (Schmidt et al., 2017. Axonal synapse sorting in medial entorhinal cortex, DOI: 10.1038/nature24005) that synapses in...
Whispering gallery mode (WGM) resonators are used to make tiny micro-lasers, sensors, switches, routers and other devices. These tiny structures rely on a...
Using ultrafast flashes of laser and x-ray radiation, scientists at the Max Planck Institute of Quantum Optics (Garching, Germany) took snapshots of the briefest electron motion inside a solid material to date. The electron motion lasted only 750 billionths of the billionth of a second before it fainted, setting a new record of human capability to capture ultrafast processes inside solids!
When x-rays shine onto solid materials or large molecules, an electron is pushed away from its original place near the nucleus of the atom, leaving a hole...
19.09.2017 | Event News
12.09.2017 | Event News
06.09.2017 | Event News
25.09.2017 | Physics and Astronomy
25.09.2017 | Trade Fair News
25.09.2017 | Physics and Astronomy