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.
Alexander Ermakov | alfa
Rainbow colors reveal cell history: Uncovering β-cell heterogeneity
22.09.2017 | DFG-Forschungszentrum für Regenerative Therapien TU Dresden
The pyrenoid is a carbon-fixing liquid droplet
22.09.2017 | Max-Planck-Institut für Biochemie
Plants and algae use the enzyme Rubisco to fix carbon dioxide, removing it from the atmosphere and converting it into biomass. Algae have figured out a way to increase the efficiency of carbon fixation. They gather most of their Rubisco into a ball-shaped microcompartment called the pyrenoid, which they flood with a high local concentration of carbon dioxide. A team of scientists at Princeton University, the Carnegie Institution for Science, Stanford University and the Max Plank Institute of Biochemistry have unravelled the mysteries of how the pyrenoid is assembled. These insights can help to engineer crops that remove more carbon dioxide from the atmosphere while producing more food.
A warming planet
Our brains house extremely complex neuronal circuits, whose detailed structures are still largely unknown. This is especially true for the so-called cerebral cortex of mammals, where among other things vision, thoughts or spatial orientation are being computed. Here the rules by which nerve cells are connected to each other are only partly understood. A team of scientists around Moritz Helmstaedter at the Frankfiurt Max Planck Institute for Brain Research and Helene Schmidt (Humboldt University in Berlin) have now discovered a surprisingly precise nerve cell connectivity pattern in the part of the cerebral cortex that is responsible for orienting the individual animal or human in space.
The researchers report online in Nature (Schmidt et al., 2017. Axonal synapse sorting in medial entorhinal cortex, DOI: 10.1038/nature24005) that synapses in...
Whispering gallery mode (WGM) resonators are used to make tiny micro-lasers, sensors, switches, routers and other devices. These tiny structures rely on a...
Using ultrafast flashes of laser and x-ray radiation, scientists at the Max Planck Institute of Quantum Optics (Garching, Germany) took snapshots of the briefest electron motion inside a solid material to date. The electron motion lasted only 750 billionths of the billionth of a second before it fainted, setting a new record of human capability to capture ultrafast processes inside solids!
When x-rays shine onto solid materials or large molecules, an electron is pushed away from its original place near the nucleus of the atom, leaving a hole...
For the first time, physicists have successfully imaged spiral magnetic ordering in a multiferroic material. These materials are considered highly promising candidates for future data storage media. The researchers were able to prove their findings using unique quantum sensors that were developed at Basel University and that can analyze electromagnetic fields on the nanometer scale. The results – obtained by scientists from the University of Basel’s Department of Physics, the Swiss Nanoscience Institute, the University of Montpellier and several laboratories from University Paris-Saclay – were recently published in the journal Nature.
Multiferroics are materials that simultaneously react to electric and magnetic fields. These two properties are rarely found together, and their combined...
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