Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Bacteria Precipitate Gold

29.07.2002


Roman A. Amosov and a team of Russian scientists from the Central Institute for Geological Exploration of Non-ferrous and Noble Metals, Institute of Paleontology, Russian Academy of Sciences, and from the Institute of Microbiology, Russian Academy of Sciences, led by, have managed to simulate in the laboratory the process of precipitation of gold which in the natural geothermal wells is promoted by blue-green algae (cyanobacteriae).



For the purposes of the experiment Vladimir Orleanski of the Institute of Microbiology, grew cyanobacteriae in the medium containing high percentage of gold chloride (from 200-300 mg up to 500 mg per milliliter). Each day Vladimir Orleanski would alternate the above medium with a regular one, which did not contain gold chloride. This way the microbiologist simulated the environment of the pulsatory thermal wells located in the geological break-up areas. The matter is that such wells regularly discharge from the lower crust the hot solutions rich in chlorides of noble metals. The microbiologist has achieved a remarkable result - in the course of the experiment gold was precipitating on the surface and inside the cells of cyanobacteriae.

It is worth noting that precipitation of gold from chloride solutions takes place only in the daylight, the process ceasing in the dark. Precipitation of gold appears to be a previously unknown photochemical process. Evidently, biological molecules serve as catalysts in the process. For half a year the scientists continued to grow the blue-green algae in the medium containing gold chloride. The algae colonies obtained this way had an evidently expressed laminated structure, where regular sections alternated with auriferous ones. Spectroscopic analysis of dried up cyanobacteriae has proved that they contain gold in the form of oxide. The way the microorganisms oxidise gold is still unclear, since noble metals are extremely difficult to oxidise.


The microorganisms` remnants are rather frequently found in the ores of non-ferrous metals, bauxites, phosphorites and other raw materials. The scientists have repeatedly made the assumptions that bacteria play a certain role in the formation of raw materials, including non-ferrous metal deposits. When R. A. Amosov found the remnants of blue-green algae in the gold mined from the Vorontsovo deposit in the Urals, this finding prompted him the hypothesis that the cyanobacterae were able to precipitate gold from geothermal solutions. As a result, R. A. Amosov has come to the idea of simulating this process in the laboratory.

The environment of a natural geothermal well can be simulated via the replacement of regular medium by the medium with high content of ions of gold and via the reverse replacement. However, the concentration of gold in the course of the experiment significantly exceeded its concentration in a natural geothermal well. Nevertheless, it should be acknowledged that it takes thousands of years for the deposit to be formed in the natural environment, while in the experiment gold was precipitated within half a year only.

Now the scientists have got solid experimental proof of the hypothesis that some gold deposits are of biological origin (at least, the Vorontsovo deposit is). The researchers also believe that it may be possible to get gold from thermal wells with the help of microorganisms.

Alexander Ermakov | alfa

More articles from Life Sciences:

nachricht More genes are active in high-performance maize
19.01.2018 | Rheinische Friedrich-Wilhelms-Universität Bonn

nachricht How plants see light
19.01.2018 | Albert-Ludwigs-Universität Freiburg im Breisgau

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Artificial agent designs quantum experiments

On the way to an intelligent laboratory, physicists from Innsbruck and Vienna present an artificial agent that autonomously designs quantum experiments. In initial experiments, the system has independently (re)discovered experimental techniques that are nowadays standard in modern quantum optical laboratories. This shows how machines could play a more creative role in research in the future.

We carry smartphones in our pockets, the streets are dotted with semi-autonomous cars, but in the research laboratory experiments are still being designed by...

Im Focus: Scientists decipher key principle behind reaction of metalloenzymes

So-called pre-distorted states accelerate photochemical reactions too

What enables electrons to be transferred swiftly, for example during photosynthesis? An interdisciplinary team of researchers has worked out the details of how...

Im Focus: The first precise measurement of a single molecule's effective charge

For the first time, scientists have precisely measured the effective electrical charge of a single molecule in solution. This fundamental insight of an SNSF Professor could also pave the way for future medical diagnostics.

Electrical charge is one of the key properties that allows molecules to interact. Life itself depends on this phenomenon: many biological processes involve...

Im Focus: Paradigm shift in Paris: Encouraging an holistic view of laser machining

At the JEC World Composite Show in Paris in March 2018, the Fraunhofer Institute for Laser Technology ILT will be focusing on the latest trends and innovations in laser machining of composites. Among other things, researchers at the booth shared with the Aachen Center for Integrative Lightweight Production (AZL) will demonstrate how lasers can be used for joining, structuring, cutting and drilling composite materials.

No other industry has attracted as much public attention to composite materials as the automotive industry, which along with the aerospace industry is a driver...

Im Focus: Room-temperature multiferroic thin films and their properties

Scientists at Tokyo Institute of Technology (Tokyo Tech) and Tohoku University have developed high-quality GFO epitaxial films and systematically investigated their ferroelectric and ferromagnetic properties. They also demonstrated the room-temperature magnetocapacitance effects of these GFO thin films.

Multiferroic materials show magnetically driven ferroelectricity. They are attracting increasing attention because of their fascinating properties such as...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

10th International Symposium: “Advanced Battery Power – Kraftwerk Batterie” Münster, 10-11 April 2018

08.01.2018 | Event News

See, understand and experience the work of the future

11.12.2017 | Event News

Innovative strategies to tackle parasitic worms

08.12.2017 | Event News

 
Latest News

Let the good tubes roll

19.01.2018 | Materials Sciences

How cancer metastasis happens: Researchers reveal a key mechanism

19.01.2018 | Health and Medicine

Meteoritic stardust unlocks timing of supernova dust formation

19.01.2018 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>