Navigation Links
Toxic methylmercury-producing microbes more widespread than realized

Microbes that live in rice paddies, northern peat bogs and other previously unexpected environments are among the bacteria that can generate highly toxic methylmercury, researchers at Oak Ridge National Laboratory and the Smithsonian Environmental Research Center have learned.

This finding, published in Environmental Science and Technology, explains why deadly methylated mercury is produced in areas where the neurotoxin's presence has puzzled researchers for decades. Methylmercury the most dangerous form of mercury damages the brain and immune system and is especially harmful to developing embryos. Certain bacteria transform inorganic mercury into toxic methylmercury.

The discovery also validates the recent finding that two genes are essential for the methylation of mercury. Previously, only a narrow range of microbes were recognized as mercury methylators, said co-author Dwayne Elias of the Department of Energy laboratory's Biosciences Division.

"We showed for the first time that many different types of bacteria are able to produce this potent neurotoxin," Elias said. "The newly identified microbes include methane-producing organisms that live in rice paddies, anaerobic wastewater treatment plants, northern peat lands and possibly within our bodies."

Elias and colleagues are testing a bacterium from the human intestine that they predict will also methylate mercury. Other bacteria able to transform inorganic into methylmercury include those used in biological dechlorination and metal treatment systems. All of these organisms are anaerobic, which means they grow in habitats without oxygen, including aquatic sediments and wetland soils.

By identifying these organisms, the researchers may have explained why methylmercury is accumulating in unexpected places. The discovery may also help clarify how methylmercury is produced in the open ocean, according to co-author Cindy Gilmour of the Smithsonian Environmental Research Center. Gilmour noted that the newly identified fermentative bacteria may be common in the low oxygen zones of the ocean where methylmercury production occurs. Ocean fish are the primary source of methylmercury in human diets worldwide.

Gilmour and Elias believe this work will have far-reaching implications for understanding the global mercury cycle. Scientists can now use the mercury-methylating organisms and their genes as global biomarkers and develop detection techniques to assess and eventually predict the extent of methylmercury production in a given environment.

"Based on the substantially expanded diversity of organisms and environments for methylation, a number of important habitats deserve further attention," Gilmour said. "We now have a way to identify and track the abundance of mercury-methylating organisms within these environments, and we hope that the information can be used to devise strategies to minimize methylmercury production."

Mercury is a global pollutant, released to the atmosphere through coal burning and other industrial uses, and through natural processes. Most of the harm comes from methylmercury bioaccumulation, which is the buildup of the element in tissue that occurs when moving up the food chain.


Contact: Ron Walli
DOE/Oak Ridge National Laboratory

Related biology news :

1. Better tests for liver toxicity would mean more medicines -- and safer medicines -- for patients
2. Computing toxic chemicals
3. Low levels of toxic proteins linked to brain diseases, study suggests
4. Children living near toxic waste sites experience higher blood lead levels resulting in lower IQ
5. Toxic waste sites cause healthy years of life lost
6. Science surprise: Toxic protein made in unusual way may explain brain disorder
7. Joint air toxics research project among tribes, agencies recognized for partnership
8. When hungry, Gulf of Mexico algae go toxic
9. Home toxic home
10. How to thrive in battery acid and among toxic metals
11. Toxic oceans may have delayed spread of complex life
Post Your Comments:
(Date:4/19/2017)... , April 19, 2017 ... its vendor landscape is marked by the presence of ... is however held by five major players - 3M ... these companies accounted for nearly 61% of the global ... leading companies in the global military biometrics market boast ...
(Date:4/13/2017)... Calif. , April 13, 2017 UBM,s ... York will feature emerging and evolving technology ... Both Innovation Summits will run alongside the expo portion ... speaker sessions, panels and demonstrations focused on trending topics ... largest advanced design and manufacturing event will take place ...
(Date:4/11/2017)... 2017 Research and Markets has announced the ... to their offering. ... eye tracking market to grow at a CAGR of 30.37% during ... Market 2017-2021, has been prepared based on an in-depth market analysis ... and its growth prospects over the coming years. The report also ...
Breaking Biology News(10 mins):
(Date:10/12/2017)... ... , ... They call it the “hairy ball.” It’s an ... a system of linkages and connections so complex and dense that “it looks ... at Worcester Polytechnic Institute (WPI) and director of the university’s bioinformatics and computational ...
(Date:10/12/2017)... ... October 12, 2017 , ... ... Lithuania, announced today that they have entered into a multiyear collaboration to identify ... CRISPR researchers with additional tools for gene editing across all applications. , Under ...
(Date:10/12/2017)... ca (PRWEB) , ... October 12, 2017 , ... ... the Surgical Wound Market with the addition of its newest module, US Hemostats ... $1.2B market for thrombin hemostats, absorbable hemostats, fibrin sealants, synthetic sealants and biologic ...
(Date:10/12/2017)... ... October 12, 2017 , ... ... Rosalind™, the first-ever genomics analysis platform specifically designed for life science researchers ... honor of pioneering researcher Rosalind Franklin, who made a major contribution to ...
Breaking Biology Technology: