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  1. Underground Life Powered by Electrons


    Scanning electron microscopy showing attachment of Delftia sp. WE1-13 on carbon cloth fibers, and in vivo fluorescent image of Delftia sp. WE1-13 cells attached to an electrode during electrochemical analysis. Image source: Y. Jangir and M.Y. El-Naggar (USC). Image credit: None
    Scanning electron microscopy showing attachment of Delftia sp. WE1-13 on carbon cloth fibers, and in vivo fluorescent image of Delftia sp. WE1-13 cells attached to an electrode during electrochemical analysis. Image source: Y. Jangir and M.Y. El-Naggar (USC).

    Scientists from the University of Southern California Life Underground team are taking a close look at microorganisms that have developed unique strategies for surviving below the Earth’s surface in oxygen-poor but mineral-rich environments.

    In the research paper “Isolation and characterization of electrochemically active subsurface Delftia and Azonexus species,” published in Frontiers of Microbiology, the scientists analyze microbes within a fractured-rock aquifer in Death Valley, CA, using electrodes to draw out and isolate types that gain energy through a process called extracellular electron transfer (EET).

    The study is part of growing research on microorganisms able to “live off of electricity ...

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  1. Fourth Library of Congress Astrobiology Chair Announced


    Luis Campos named fourth Baruch S. Blumberg NASA/Library of Congress Chair. Photo credits: University of New Mexico/Library of Congress. Image credit:
    Luis Campos named fourth Baruch S. Blumberg NASA/Library of Congress Chair. Photo credits: University of New Mexico/Library of Congress.

    Luis Campos has been selected as the fourth Baruch S. Blumberg NASA/Library of Congress Chair in Astrobiology at the Library of Congress John W. Kluge Center.

    Campos is a senior fellow at the Robert Wood Johnson Foundation Center for Health Policy at the University of New Mexico, where he also teaches the history of science. His writings include “Radium and the Secret of Life,” and he is co-editor of “Making Mutations: Objects, Practices, Contexts.”

    His yearlong residency at the Kluge Center begins October 1. Campos will focus on the intersection between astrobiology and synthetic biology, examining the ...

    Source: [Library of Congress]

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  1. Where Is the Habitable Zone for M-Dwarf Stars?


    While we know that yellow dwarf stars like our sun are capable of supporting life, there’s another star type that is a prime hunting ground for potentially habitable exoplanets.

    M-dwarf stars are extremely common in the Universe and a typical one is relatively small and dim, making it easy for astronomers to detect a passing planet. If orbiting planets huddle close enough to an M-dwarf, in theory they could fall within the habitable zone where surface liquid water, and thus life, is possible.

    Artist’s impression of a M dwarf star surrounded by planets. Image credit: NASA/JPL-Caltech/MSSS
    Artist’s impression of a M dwarf star surrounded by planets.

    Source: [astrobio.net]

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  1. Europa's Ocean May Have an Earthlike Chemical Balance


    Image credit: None

    The ocean of Jupiter’s moon Europa could have the necessary balance of chemical energy for life, even if the moon lacks volcanic hydrothermal activity, finds a new study.

    Europa is strongly believed to hide a deep ocean of salty liquid water beneath its icy shell. Whether the Jovian moon has the raw materials and chemical energy in the right proportions to support biology is a topic of intense scientific interest. The answer may hinge on whether Europa has environments where chemicals are matched in the right proportions to power biological processes. Life on Earth exploits such niches.

    In the ...

    Source: [American Geophysical Union]

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  1. A Possible Solution to the “Faint Young Sun Paradox” in Primordial Asteroid Impacts


    SwRI scientists created a new model for impact-generated outgassing on the early Earth. A large impact creates a transient high temperature atmosphere. Within a thousand years, the atmosphere condenses, while deep-seated, impact-generated melt spreads across the surface. The model shows how pools of lava could release gases and create a greenhouse effect that warmed the planet.  Image credit: Simone Marchi (SwRI), Benjamin Black (City College of New York)
    SwRI scientists created a new model for impact-generated outgassing on the early Earth. A large impact creates a transient high temperature atmosphere. Within a thousand years, the atmosphere condenses, while deep-seated, impact-generated melt spreads across the surface. The model shows how pools of lava could release gases and create a greenhouse effect that warmed the planet.

    In the first billion years of Earth’s history, the planet was bombarded by primordial asteroids, while a faint Sun provided much less heat. A Southwest Research Institute-led team posits that this tumultuous beginning may have ultimately fostered life on Earth, particularly in terms of sustaining liquid water.

    “The early impacts caused temporary, localized destruction and hostile conditions for life. But at the same time, they had a long-term beneficial effect in stabilizing surface temperatures and delivering key elements for life as we know it,” said Dr. Simone Marchi, a senior research scientist at SwRI’s Planetary Science Directorate in ...

    Source: [Southwest Research Institute]

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  1. Watching ‘Jumping Genes’ in Action


    A bacterial colony showing individual cells undergoing transposable element events, resulting in blue fluorescence. Images are shown at (a) t = 0, (b) t = 40 min, and (c) t = 60 min, with arrows indicating newly occurring events in each image. Image courtesy of T.E. Kuhlman, University of Illinois at Urbana-Champaign, reproduced with permission from Proceedings of the National Academy of Sciences USA. Image credit: None
    A bacterial colony showing individual cells undergoing transposable element events, resulting in blue fluorescence. Images are shown at (a) t = 0, (b) t = 40 min, and (c) t = 60 min, with arrows indicating newly occurring events in each image. Image courtesy of T.E. Kuhlman, University of Illinois at Urbana-Champaign, reproduced with permission from Proceedings of the National Academy of Sciences USA.

    “Jumping genes” are ubiquitous. Every domain of life hosts these sequences of DNA that can “jump” from one position to another along a chromosome; in fact, nearly half the human genome is made up of jumping genes. Depending on their specific excision and insertion points, jumping genes can interrupt or trigger gene expression, driving genetic mutation and contributing to cell diversification. Since their discovery in the 1940s, researchers have been able to study the behavior of these jumping genes, generally known as transposons or transposable elements (TE), primarily through indirect methods that infer individual activity from bulk results. However, such ...

    Source: [University of Illinois at Urbana-Champaign]

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  1. Chiral Molecule Detected in Interstellar Space


    Propylene oxide was detected, primarily with the NSF's Green Bank Telescope, near the center of our Galaxy in Sagittarius (Sgr) B2, a massive star-forming region. Credit: B. Saxton, NRAO/AUI/NSF from data provided by N.E. Kassim, Naval Research Laboratory Image credit:
    Propylene oxide was detected, primarily with the NSF's Green Bank Telescope, near the center of our Galaxy in Sagittarius (Sgr) B2, a massive star-forming region. Credit: B. Saxton, NRAO/AUI/NSF from data provided by N.E. Kassim, Naval Research Laboratory

    A team of scientists using highly sensitive radio telescopes have discovered the first complex organic chiral molecule in interstellar space. The molecule, propylene oxide (CH3CHOCH2), was found near the center of our Galaxy in an enormous star-forming cloud of dust and gas known as Sagittarius B2 (Sgr B2).

    The research was undertaken primarily with the National Science Foundation’s Green Bank Telescope (GBT) in West Virginia as part of the Prebiotic Interstellar Molecular Survey. Additional supporting observations were taken with the Parkes radio telescope in Australia.

    “This is the first molecule detected in interstellar space that has the ...

    Source: [National Radio Astronomy Observatory]

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  1. Postdoctoral Fellowship Opportunity with NASA’s Nexus for Exoplanet System Science (NExSS)


    Image credit: None

    The NASA Postdoctoral Program (NPP) offers U.S. and international scientists the opportunity to conduct important research while contributing to NASA’s scientific goals. Applications are now being accepted for postdoctoral fellows to engage in research with NASA’s Nexus for Exoplanet System Science (NExSS) advisors.

    NExSS is a NASA research coordination network dedicated to the study of planetary habitability. The goals of NExSS are to investigate the diversity of exoplanets and to learn how their history, geology, and climate interact to create the conditions for life (https://nexss.info/). NExSS investigators also strive to put planets into an architectural ...

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  1. Pre-Workshop Activities for Exoplanet Biosignatures Workshop Without Walls


    Image credit: None

    The pre-workshop online activities for the NExSS Exoplanet Biosignatures Workshop Without Walls will commence on June 13! We are pleased to let you know that 3 pairs of meetings will be timed to engage participants across the globe.

    These pre-workshop activities will be community work sessions to review the State of the Science of remotely detectable biosignatures. The results will be summarized at the 3-day in-person workshop in July, where they will facilitate discussions for Advancing the Science and Technology for exoplanet biosignatures.

    State of the Science Review
    The length of each meeting will be 75 minutes.

    Meeting 1: Topic ...

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  1. Joint NASA-NSF Ideas Lab on the Origins of Life


    This artist's conception symbolically represents complex organic molecules, known as polycyclic aromatic hydrocarbons, seen in the early universe. These large molecules, comprised of carbon and hydrogen, are among the building blocks of life. Image credit: None
    This artist's conception symbolically represents complex organic molecules, known as polycyclic aromatic hydrocarbons, seen in the early universe. These large molecules, comprised of carbon and hydrogen, are among the building blocks of life. The molecules shown, called quinones, are potentially significant for the “origin of life” or the habitability of planets. Image credit: None
    The molecules shown, called quinones, are potentially significant for the “origin of life” or the habitability of planets.

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  1. Earth’s ancient atmosphere was half as thick as it is today


    One of the lava flows analyzed in the study, from the shore of Australia’s Beasley River. Gas bubbles that formed as the lava cooled, 2.7 billion years ago, have since filled with calcite and other minerals. The bubbles now look like white spots. Researchers compared bubble sizes from the top and bottom of the lava flows to measure the ancient air pressure. Image credit: None
    One of the lava flows analyzed in the study, from the shore of Australia’s Beasley River. Gas bubbles that formed as the lava cooled, 2.7 billion years ago, have since filled with calcite and other minerals. The bubbles now look like white spots. Researchers compared bubble sizes from the top and bottom of the lava flows to measure the ancient air pressure. The layers on this 2.7 billion-year-old rock, a stromatolite from Western Australia, show evidence of single-celled, photosynthetic life on the shore of a large lake. The new result suggests that this microbial life thrived despite a thin atmosphere. Image credit: None
    The layers on this 2.7 billion-year-old rock, a stromatolite from Western Australia, show evidence of single-celled, photosynthetic life on the shore of a large lake. The new result suggests that this microbial life thrived despite a thin atmosphere.

    Source: [University of Washington]

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  1. Below the Chemocline in a Meromictic Lake


    Mahoney Lake in British Columbia. Image credit: W. P. Gilhooly III
    Mahoney Lake in British Columbia.

    Metagenomic sequencing has provided new information about understudied populations of microorganisms that inhabit Mahoney Lake in British Columbia at depths where light does not reach. Mahoney Lake is an extreme meromictic system, meaning that the lake contains layers of water that do not mix. There is a great deal of information concerning microorganisms that live in sunlit portions of Mahoney Lake, and similar anoxic systems that contain high levels of sulfate and sulfide in the water column. However, less is known about communities living at depths below the photic zone.

    The new study provides insight into the the types of ...

    Source: [Frontiers in Microbiology]

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  1. Early Career Seminar: Chemical Gardens, Chimneys, and Fuel Cells: Simulating Prebiotic Chemistry in Hydrothermal Vents on Ocean Worlds


    Image credit: None

    On Wednesday, June 1, 2016 at 11AM PDT, Laura Barge, NASA Jet Propulsion Laboratory, will be presenting the next early career seminar, Early Career Seminar: Chemical Gardens, Chimneys, and Fuel Cells: Simulating Prebiotic Chemistry in Hydrothermal Vents on Ocean Worlds.

    Abstract: Planetary water-rock interfaces generate energy in the form of redox, pH, and thermal gradients, particularly in hydrothermal systems where the reducing, heated vent fluid feeds back into the more oxidizing ocean. Alkaline vents produced by serpentinization have been proposed as a possible location for the emergence of life on the early Earth due to various factors, including the mineral ...

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  1. Genetic Studies of a Hyperthermophilic Archaeon


    Lead author, Changyi Zhang, collecting samples in September 2014 at a hot spring in Yellowstone National Park. Image credit: Zhang et a. (2016)/University of Illinois at Urbana-Champaign
    Lead author, Changyi Zhang, collecting samples in September 2014 at a hot spring in Yellowstone National Park.

    Scientists from Carl R. Woese Institute for Genomic Biology have identified a new genetic marker (the apt gene) in a species of archaea named Sulfolobus islandicus. S. islandicus is a hyperthermophilic member of the phylum Crenarchaeota, and can be found in environments like volcanic springs with temperatures up to 91°C. Currently, S. islandicus is rapidly developing as a model for studying archaeal biology as well as linking novel biology to evolutionary ecology using functional population genomics.

    Previously, only one similar genetic marker (the pyrEF gene) was known for Sulfolobus species. However, the majority of Sulfolobus mutants that have been ...

    Source: [Applied and Environmental Microbiology]

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  1. New Insight into Microbial Communities in Anoxic Sediments


    Scanning electron micrographs of anaerobic Fe(II)-oxidizing cultures. From: Schadler et al. (2009) Formation of Cell-Iron-Mineral Aggregates by Phototrophic and Nitrate-Reducing Anaerobic Fe(II)-Oxidizing Bacteria, Geomicrobiology Journal.  Image credit: Reprinted by permission of Taylor & Francis LLC, (http://www.tandfonline.com)
    Scanning electron micrographs of anaerobic Fe(II)-oxidizing cultures. From: Schadler et al. (2009) Formation of Cell-Iron-Mineral Aggregates by Phototrophic and Nitrate-Reducing Anaerobic Fe(II)-Oxidizing Bacteria, Geomicrobiology Journal.

    A new study provides insight into a well-recognized chemolithotrophic pathway that can be used by microorganisms inhabiting anoxic sediments. Researchers used an enrichment culture of chemolithoautotrophic organisms from freshwater sediments (dubbed Culture KS) as a model system to study the pathway: nitrate-dependent ferrous iron [Fe(II)] oxidation (NDFO).

    Previous efforts to isolate the organism responsible for the oxidation of iron [Fe(II)] in Culture KS had proven unsuccessful. In the new study, researchers used metagenomic analysis to better understand the roles of different bacteria in Culture KS. Using this method, they were able to identify the primary Fe(II)-oxidizer ...

    Source: [Applied Environmental Microbiology]

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