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 Ion treatments for cardiac arrhythmia — Non-invasive alternative to catheter-based surgery
20.01.2017 | GSI Helmholtzzentrum für Schwerionenforschung GmbH

nachricht Seeking structure with metagenome sequences
20.01.2017 | DOE/Joint Genome Institute

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Traffic jam in empty space

New success for Konstanz physicists in studying the quantum vacuum

An important step towards a completely new experimental access to quantum physics has been made at University of Konstanz. The team of scientists headed by...

Im Focus: How gut bacteria can make us ill

HZI researchers decipher infection mechanisms of Yersinia and immune responses of the host

Yersiniae cause severe intestinal infections. Studies using Yersinia pseudotuberculosis as a model organism aim to elucidate the infection mechanisms of these...

Im Focus: Interfacial Superconductivity: Magnetic and superconducting order revealed simultaneously

Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.

While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...

Im Focus: Studying fundamental particles in materials

Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales

Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...

Im Focus: Designing Architecture with Solar Building Envelopes

Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.

As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Sustainable Water use in Agriculture in Eastern Europe and Central Asia

19.01.2017 | Event News

12V, 48V, high-voltage – trends in E/E automotive architecture

10.01.2017 | Event News

2nd Conference on Non-Textual Information on 10 and 11 May 2017 in Hannover

09.01.2017 | Event News

 
Latest News

Helmholtz International Fellow Award for Sarah Amalia Teichmann

20.01.2017 | Awards Funding

An innovative high-performance material: biofibers made from green lacewing silk

20.01.2017 | Materials Sciences

Ion treatments for cardiac arrhythmia — Non-invasive alternative to catheter-based surgery

20.01.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>