Scientists at the Carnegie Institutions Department of Plant Biology have found that photosynthetic bacteria living in scalding Yellowstone hot springs have two radically different metabolic identities. As the sun goes down, these cells quit their day job of photosynthesis and unexpectedly begin to fix nitrogen, converting nitrogen gas (N2) into compounds that are useful for cell growth. The study, published January 30 in the early online edition of the Proceedings of the National Academy of Sciences, is the first to document an organism that can juggle both metabolic tasks within a single cell at high temperatures, and also helps answer longstanding questions about how hot-spring microbial communities get essential nitrogen compounds.
The near-boiling pools of Octopus Spring in Yellowstone National Park are ringed with microbial mats – highly organized communities where photosynthetic cyanobacteria serve as the main power plants. Researchers have found that the single-celled cyanobacterium Synechococcus drops its day job of photosynthesis, and surprisingly fixes nitrogen gas (N2) into biologically useful compounds at night.
Carnegies Arthur Grossman, Devaki Bhaya, and Anne-Soisig Steunou, along with colleagues from four partner institutions*, are studying the tiny, single-celled cyanobacterium Synechococcus. Cyanobacteria evolved about three billion years ago, and are the oldest organisms on the planet that can turn solar energy and carbon dioxide into sugars and oxygen via photosynthesis. In fact, ancient cyanobacteria produced most of the oxygen that allows animals to survive on Earth.
Cyanobacteria such as Synechococcus are often found in the microbial mats that carpet hot springs, where life exists at near-boiling temperatures. These mats are highly organized communities where different organisms split up the work, with cyanobacteria serving as the main photosynthetic power plants. Microbial mats in Yellowstone National Parks Octopus Spring contain Synechococcus that can grow in waters up to around 160°F, while other microbes in the hot spring can tolerate temperatures that exceed 175°F. But until now, it was unclear which organisms could fix nitrogen--especially in the hotter regions of the mat.
Dr. Arthur Grossman | EurekAlert!
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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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