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 How does the loss of species alter ecosystems?
18.05.2017 | Deutsches Zentrum für integrative Biodiversitätsforschung (iDiv) Halle-Jena-Leipzig

nachricht Excess diesel emissions bring global health & environmental impacts
16.05.2017 | 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: Turmoil in sluggish electrons’ existence

An international team of physicists has monitored the scattering behaviour of electrons in a non-conducting material in real-time. Their insights could be beneficial for radiotherapy.

We can refer to electrons in non-conducting materials as ‘sluggish’. Typically, they remain fixed in a location, deep inside an atomic composite. It is hence...

Im Focus: Wafer-thin Magnetic Materials Developed for Future Quantum Technologies

Two-dimensional magnetic structures are regarded as a promising material for new types of data storage, since the magnetic properties of individual molecular building blocks can be investigated and modified. For the first time, researchers have now produced a wafer-thin ferrimagnet, in which molecules with different magnetic centers arrange themselves on a gold surface to form a checkerboard pattern. Scientists at the Swiss Nanoscience Institute at the University of Basel and the Paul Scherrer Institute published their findings in the journal Nature Communications.

Ferrimagnets are composed of two centers which are magnetized at different strengths and point in opposing directions. Two-dimensional, quasi-flat ferrimagnets...

Im Focus: World's thinnest hologram paves path to new 3-D world

Nano-hologram paves way for integration of 3-D holography into everyday electronics

An Australian-Chinese research team has created the world's thinnest hologram, paving the way towards the integration of 3D holography into everyday...

Im Focus: Using graphene to create quantum bits

In the race to produce a quantum computer, a number of projects are seeking a way to create quantum bits -- or qubits -- that are stable, meaning they are not much affected by changes in their environment. This normally needs highly nonlinear non-dissipative elements capable of functioning at very low temperatures.

In pursuit of this goal, researchers at EPFL's Laboratory of Photonics and Quantum Measurements LPQM (STI/SB), have investigated a nonlinear graphene-based...

Im Focus: Bacteria harness the lotus effect to protect themselves

Biofilms: Researchers find the causes of water-repelling properties

Dental plaque and the viscous brown slime in drainpipes are two familiar examples of bacterial biofilms. Removing such bacterial depositions from surfaces is...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

AWK Aachen Machine Tool Colloquium 2017: Internet of Production for Agile Enterprises

23.05.2017 | Event News

Dortmund MST Conference presents Individualized Healthcare Solutions with micro and nanotechnology

22.05.2017 | Event News

Innovation 4.0: Shaping a humane fourth industrial revolution

17.05.2017 | Event News

 
Latest News

Scientists propose synestia, a new type of planetary object

23.05.2017 | Physics and Astronomy

Zap! Graphene is bad news for bacteria

23.05.2017 | Life Sciences

Medical gamma-ray camera is now palm-sized

23.05.2017 | Medical Engineering

VideoLinks
B2B-VideoLinks
More VideoLinks >>>