Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Rare earths in bacteria

31.10.2013
Methane-decomposing bacteria from hot springs need the valuable metals to produce energy

Rare earths are among the most precious raw materials of all. These metals are used in mobile telephones, display screens and computers. And they are apparently indispensable for some organisms as well.


The methanol dehydrogenase of the bacterium Methylacidiphilum fumariolicum uses the rare earths metal cerium (Ce) as co-factor.
© MPI f. Medical Research/Barends

A team of researchers, including scientists from the Max Planck Institute for Medical Research in Heidelberg, has discovered a bacterium which needs rare earths to grow - in a hot spring. Methylacidiphilum fumariolicum requires lanthanum, cerium, praseodymium or neodymium as co-factor for the enzyme methanol dehydrogenase, with which the microbes produce their energy. The use of rare earths is possibly more widespread among bacteria than previously thought.

In reality, the 17 metals that belong to the group of rare earths are not rare at all. The Earth’s crust contains larger quantities of rare earths than of gold or platinum, for example. The problem is that the elements have a relatively even distribution, so that mining is economical in only a few places.

In living organisms, the rare earths really are rare, on the other hand. As they dissolve hardly at all in water, most organisms cannot use them for their metabolism. This makes their discovery in a mudpot of volcanic origin in the Solfatara crater in Italy all the more surprising. Microbiologists from the Radboud University in Nijmegen, the Netherlands, have found a microbe which cannot live without some of the rare earths. Methylacidiphilum fumariolicum belongs to a group of bacteria which have chosen an extremely inhospitable habitat: They thrive best at a pH value of between 2 and 5 and temperatures of between 50 and 60 degrees - conditions which are lethal for other organisms. Methylacidiphilum even tolerates pH values below 1, which corresponds to concentrated sulphuric acid.

The microbes produce their energy from methane. They have a special enzyme, methanol dehydrogenase, which processes the methanol produced in the decomposition of methane with the aid of metal co-factors. Most of these bacteria use calcium for this process.

In the course of their investigations, the Nijmegen researchers noticed that Methylacidiphilum thrives only with original water from the mudpot. None of the trace elements which the researchers added to the Petri dishes encouraged the bacteria to grow. An analysis of the water showed that it contained concentrations of rare earths that were one hundred to one thousand times higher than normal.

Thomas Barends and Andreas Dietl from the Max Planck Institute for Medical Research investigated the three-dimensional structure of methanol dehydrogenase. They thereby noticed that Methylacidiphilum fumariolicum had inserted not calcium, but an atom of a different metal in its methanol dehydrogenase.

“Suddenly, everything fit together,” explains Thomas Barends. “We were able to show that this mysterious atom must be a rare earth. This is the first time ever that rare earths have been found to have such a biological function.” Methylacidiphilum uses the rare earths lanthanum, cerium, praseodymium and neodymium in its methanol dehydrogenase instead of calcium. The bacterium needs them to produce energy from methane.

The rare earths have a slightly larger ion radius than calcium, but can still replace it as a co-factor of enzymes. “Individual amino acids have been exchanged in the amino acid chain of the methanol dehydrogenase of the bacterium. This creates more room for the metals,” says Barends. In addition, Methylacidiphilum digests a larger quantity of rare earths than it needs to survive. It is therefore possible that it stores the metals in the cell.

Genome and proteome analyses suggest that the Methylacidiphilum version of methanol dehydrogenase is widespread among bacteria from coastal waters. Scientists have also discovered methane-exploiting bacteria equipped with this on the leaf surface of plants. Plants can enrich rare earths and thus safeguard the supply for the bacteria. “These bacteria are possibly present anywhere there is a sufficient supply of sand, as sand is an almost inexhaustible source of rare earths,” says Barends.

Contact

Dr. Thomas Barends
Max Planck Institute for Medical Research, Heidelberg
Phone: +49 6221 486-508
Email: thomas.barends@­mpimf-heidelberg.mpg.de
Dr. John Wray
Max Planck Institute for Medical Research, Heidelberg
Phone: +49 6221 486-277
Fax: +49 6221 486-351
Email: wray@­mpimf-heidelberg.mpg.de
Original publication
Arjan Pol, Thomas R. M. Barends, Andreas Dietl, Ahmad F. Khadem, Jelle Eygensteyn, Mike S. M. Jetten, and Huub J. M. Op den Camp
Rare earth metals are essential for methanotrophic life in volcanic mudpots
Environmental Microbiology, October 2013, doi:10.1111/1462-2920.12249

Dr. Thomas Barends | Max-Planck-Institute
Further information:
http://www.mpg.de/7591932/rare-earths-bacteria

More articles from Studies and Analyses:

nachricht Smart Data Transformation – Surfing the Big Wave
02.12.2016 | Fraunhofer-Institut für Angewandte Informationstechnik FIT

nachricht Climate change could outpace EPA Lake Champlain protections
18.11.2016 | University of Vermont

All articles from Studies and Analyses >>>

The most recent press releases about innovation >>>

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

Im Focus: Significantly more productivity in USP lasers

In recent years, lasers with ultrashort pulses (USP) down to the femtosecond range have become established on an industrial scale. They could advance some applications with the much-lauded “cold ablation” – if that meant they would then achieve more throughput. A new generation of process engineering that will address this issue in particular will be discussed at the “4th UKP Workshop – Ultrafast Laser Technology” in April 2017.

Even back in the 1990s, scientists were comparing materials processing with nanosecond, picosecond and femtosesecond pulses. The result was surprising:...

Im Focus: Shape matters when light meets atom

Mapping the interaction of a single atom with a single photon may inform design of quantum devices

Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...

Im Focus: Novel silicon etching technique crafts 3-D gradient refractive index micro-optics

A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.

Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...

Im Focus: Quantum Particles Form Droplets

In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.

“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...

Im Focus: MADMAX: Max Planck Institute for Physics takes up axion research

The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.

The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ICTM Conference 2017: Production technology for turbomachine manufacturing of the future

16.11.2016 | Event News

Innovation Day Laser Technology – Laser Additive Manufacturing

01.11.2016 | Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

 
Latest News

Closing the carbon loop

08.12.2016 | Life Sciences

Applicability of dynamic facilitation theory to binary hard disk systems

08.12.2016 | Physics and Astronomy

Scientists track chemical and structural evolution of catalytic nanoparticles in 3-D

08.12.2016 | Materials Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>