Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Researchers discover how soils control atmospheric hydrogen

04.03.2014

Researchers at New Zealand's University of Otago are helping to clear up an enduring mystery regarding the composition of the Earth's atmosphere. They have discovered the microbial soil processes that help ensure that the explosive gas hydrogen remains at trace levels.

In recent decades it was found that around four-fifths of all hydrogen released into the air is rapidly removed through soil activity, but exactly what is recycling it, and how, has remained unclear.

Now, Otago scientists have shown that the soil bacterium Mycobacterium smegmatis uses two special enzymes that can efficiently scavenge hydrogen as fuel at very low concentrations. They also found the bacterium ramps up these enzymes' activity when starved of its usual carbon-based energy sources.

The Department of Microbiology & Immunology researchers' findings appear in the prestigious journal Proceedings of the National Academy of Sciences (PNAS). Their discovery has implications for improved understanding of global climate processes and for developing new catalysts for hydrogen fuel cells.

Study lead author and Otago PhD candidate Chris Greening says the findings emerge from a project led by Professor Greg Cook investigating why the mycobacteria family, which includes members causing TB and leprosy, have genes encoding hydrogenase enzymes. Hydrogenases are well-known for their roles in anaerobic bacteria, but this is the first comprehensive study of these enzymes in an organism that requires oxygen to combust their fuel sources.

"Hydrogen scavenging is just one example of the ingenuity of microorganisms. Bacterial metabolism is much more flexible than that of humans. While we rely on carbon sources such as sugars and amino acids, many bacteria can use gases (e.g. hydrogen, carbon monoxide) and even metals (e.g. iron, uranium) as fuel sources for growth and survival," says Mr Greening.

It now appears that M. smegmatis and several other species of soil actinobacteria are demonstrating a metabolic flexibility that would provide a powerful advantage over other aerobic microbes in soil ecosystems, he says.

"High-affinity hydrogenases allow these bacteria to harness hydrogen to survive on when their standard carbon-based fuel sources are absent. While hydrogen is at low concentrations in the air, it is essentially a constant and unlimited resource. This means that bacteria scavenging this highly dependable fuel source would be especially competitive against other organisms in their volatile environments."

On a global scale, this activity leads to soil actinobacteria serving as the main sink for atmospheric hydrogen. This in turn influences the concentrations of other gases in the atmosphere, including potent greenhouse gases such as methane and nitrous oxide, he says.

Mr Greening says that hydrogenases have additionally attracted interest from researchers working to make dependable, inexpensive hydrogen fuel cells a reality. "Developing a catalyst that mimics the high-affinity, oxygen-tolerant action of the hydrogenases in M. smegmatis would provide an enormous boost for this technology," he says.

Originally from the UK, Mr Greening joined Professor Cook's laboratory in November 2010 after completing a Bachelor's and Master's degree in Biochemistry at the University of Oxford. He will shortly complete his doctoral studies at Otago to take up a position researching drug targets for TB at CSIRO, Australia's national science agency.

"I decided to come here to do my PhD under Professor Cook after attending a research presentation he gave at Oxford." Having been awarded a first class degree at Oxford, Mr Greening pretty much had the choice of any world-leading institution to continue his studies. However, he says "Greg's multifaceted science captured my imagination so strongly that I set my sights on Otago."

###

The team's project was supported by a Marsden Fund Grant awarded to Professor Cook and study co-author Dr Michael Berney. The other co-authors include Kiel Hards, who studied the hydrogenases during his BSc Honours year, and Professor Dr Ralf Conrad, director of the Max-Planck Institute for Terrestrial Microbiology in Marburg, Germany.

Chris Greening | EurekAlert!

Further reports about: Greening actinobacteria activity bacteria bacterium concentrations enzymes gases soils

More articles from Ecology, The Environment and Conservation:

nachricht Northern bald ibises fit for their journey to Tuscany
21.08.2015 | Veterinärmedizinische Universität Wien

nachricht Boreal forests challenged by global change
21.08.2015 | International Institute for Applied Systems Analysis (IIASA)

All articles from Ecology, The Environment and Conservation >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: OU astrophysicist and collaborators find supermassive black holes in quasar nearest Earth

A University of Oklahoma astrophysicist and his Chinese collaborator have found two supermassive black holes in Markarian 231, the nearest quasar to Earth, using observations from NASA's Hubble Space Telescope.

The discovery of two supermassive black holes--one larger one and a second, smaller one--are evidence of a binary black hole and suggests that supermassive...

Im Focus: What would a tsunami in the Mediterranean look like?

A team of European researchers have developed a model to simulate the impact of tsunamis generated by earthquakes and applied it to the Eastern Mediterranean. The results show how tsunami waves could hit and inundate coastal areas in southern Italy and Greece. The study is published today (27 August) in Ocean Science, an open access journal of the European Geosciences Union (EGU).

Though not as frequent as in the Pacific and Indian oceans, tsunamis also occur in the Mediterranean, mainly due to earthquakes generated when the African...

Im Focus: Self-healing landscape: landslides after earthquake

In mountainous regions earthquakes often cause strong landslides, which can be exacerbated by heavy rain. However, after an initial increase, the frequency of these mass wasting events, often enormous and dangerous, declines, in fact independently of meteorological events and aftershocks.

These new findings are presented by a German-Franco-Japanese team of geoscientists in the current issue of the journal Geology, under the lead of the GFZ...

Im Focus: FIC Proteins Send Bacteria Into Hibernation

Bacteria do not cease to amaze us with their survival strategies. A research team from the University of Basel's Biozentrum has now discovered how bacteria enter a sleep mode using a so-called FIC toxin. In the current issue of “Cell Reports”, the scientists describe the mechanism of action and also explain why their discovery provides new insights into the evolution of pathogens.

For many poisons there are antidotes which neutralize their toxic effect. Toxin-antitoxin systems in bacteria work in a similar manner: As long as a cell...

Im Focus: Fraunhofer IPA develops prototype of intelligent care cart

It comes when called, bringing care utensils with it and recording how they are used: Fraunhofer IPA is developing an intelligent care cart that provides care staff with physical and informational support in their day-to-day work. The scientists at Fraunhofer IPA have now completed a first prototype. In doing so, they are continuing in their efforts to improve working conditions in the care sector and are developing solutions designed to address the challenges of demographic change.

Technical assistance systems can improve the difficult working conditions in residential nursing homes and hospitals by helping the staff in their work and...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Networking conference in Heidelberg for outstanding mathematicians and computer scientists

20.08.2015 | Event News

Scientists meet in Münster for the world’s largest Chitin und Chitosan Conference

20.08.2015 | Event News

Large agribusiness management strategies

19.08.2015 | Event News

 
Latest News

Interstellar seeds could create oases of life

28.08.2015 | Physics and Astronomy

An ounce of prevention: Research advances on 'scourge' of transplant wards

28.08.2015 | Health and Medicine

Fish Oil-Diet Benefits May be Mediated by Gut Microbes

28.08.2015 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>