Oilfields usually represent extreme environments, where physicochemical conditions appear at first sight to be generally unsuitable for living organisms to develop. However, these environments, usually poor in nitrates and oxygen, harbour a rich diverse community of microorganisms. The most widely represented and best-known types are sulfate-reducing, methanogenic and fermentative bacteria.
Nitrate-reducing bacteria, on the other hand, have received little research attention regarding their biology and role. Nevertheless some of their bacteria are known also to have the ability to oxidize sulfates. These components, which can result from metabolic activity of sulfate-reducing bacteria, prove dangerous for the environment and corrosive for drilling equipment. Nitrate injection is practised in some regions of the world in order to restrict the emission of sulfites produced during processes of exploitation of oil deposits. This input of nitrates stimulates nitrate-reducing bacteria, initially present in low quantities in the waters associated with oil reservoirs, to proliferate (2). They thus induce at once inhibition of the development of sulfate-reducing bacteria and oxidation of sulfides that such microorganisms produce.
The question remains of determining whether or not these nitrate inputs into the petroleum reservoir environment can favour the growth of populations of nitrate-reducing microorganisms different from those which oxidize the sulfides, in this way modifying the microbial ecology of oil wells. IRD scientists are therefore investigating in the laboratory the metabolism of novel nitrate-reducing bacteria, especially those able to oxidize organic acids. These acids are often present in the waters of oil reservoirs.
Marie Guillaume | alfa
Upcycling 'fast fashion' to reduce waste and pollution
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27.03.2017 | Alfred-Wegener-Institut, Helmholtz-Zentrum für Polar- und Meeresforschung
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Reflecting the structure of composites found in nature and the ancient world, researchers at the University of Illinois at Urbana-Champaign have synthesized thin carbon nanotube (CNT) textiles that exhibit both high electrical conductivity and a level of toughness that is about fifty times higher than copper films, currently used in electronics.
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The nearby, giant radio galaxy M87 hosts a supermassive black hole (BH) and is well-known for its bright jet dominating the spectrum over ten orders of magnitude in frequency. Due to its proximity, jet prominence, and the large black hole mass, M87 is the best laboratory for investigating the formation, acceleration, and collimation of relativistic jets. A research team led by Silke Britzen from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has found strong indication for turbulent processes connecting the accretion disk and the jet of that galaxy providing insights into the longstanding problem of the origin of astrophysical jets.
Supermassive black holes form some of the most enigmatic phenomena in astrophysics. Their enormous energy output is supposed to be generated by the...
The probability to find a certain number of photons inside a laser pulse usually corresponds to a classical distribution of independent events, the so-called...
Microprocessors based on atomically thin materials hold the promise of the evolution of traditional processors as well as new applications in the field of flexible electronics. Now, a TU Wien research team led by Thomas Müller has made a breakthrough in this field as part of an ongoing research project.
Two-dimensional materials, or 2D materials for short, are extremely versatile, although – or often more precisely because – they are made up of just one or a...
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