Microbial Community Structure of Subglacial Lake Whillans, West Antarctica
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Hydrogen Isotope Fractionation in Lipids of the Methane-Oxidizing Bacterium Methylococcus Capsulatus
Geochimica et Cosmochimica Acta, Vol. 66, No. 22, pp. 3955–3969, 2002 Copyright © 2002 Elsevier Science Ltd Pergamon Printed in the USA. All rights reserved 0016-7037/02 $22.00 ϩ .00 PII S0016-7037(02)00981-X Hydrogen isotope fractionation in lipids of the methane-oxidizing bacterium Methylococcus capsulatus 1, 2 3 1 ALEX L. SESSIONS, *LINDA L. JAHNKE, ARNDT SCHIMMELMANN, and JOHN M. HAYES 1Department of Geology and Geophysics, Woods Hole Oceanographic Institution, Woods Hole, MA 02543, USA 2Exobiology Branch, NASA-Ames Research Center, Moffett Field, CA 94035, USA 3Biogeochemical Laboratories, Department of Geological Sciences, Indiana University, Bloomington, IN 47405, USA (Received December 10, 2001; accepted in revised form June 7, 2002) Abstract—Hydrogen isotopic compositions of individual lipids from Methylococcus capsulatus, an aerobic, methane-oxidizing bacterium, were analyzed by hydrogen isotope-ratio-monitoring gas chromatography–mass spectrometry (GC-MS). The purposes of the study were to measure isotopic fractionation factors between methane, water, and lipids and to examine the biochemical processes that determine the hydrogen isotopic composition of lipids. M. capsulatus was grown in six replicate cultures in which the ␦D values of methane and water were varied independently. Measurement of concomitant changes in ␦D values of lipids allowed estimation of the proportion of hydrogen derived from each source and the isotopic fractionation associated with the utilization of each source. All lipids examined, including fatty acids, sterols, and hopanols, derived 31.4 Ϯ 1.7% of their hydrogen from methane. This was apparently true whether the cultures were harvested during exponential or stationary phase. Examination of the relevant biochemical pathways indicates that no hydrogen is transferred directly (with C-H bonds intact) from methane to lipids. -
Reduced Net Methane Emissions Due to Microbial Methane Oxidation in a Warmer Arctic
LETTERS https://doi.org/10.1038/s41558-020-0734-z Reduced net methane emissions due to microbial methane oxidation in a warmer Arctic Youmi Oh 1, Qianlai Zhuang 1,2,3 ✉ , Licheng Liu1, Lisa R. Welp 1,2, Maggie C. Y. Lau4,9, Tullis C. Onstott4, David Medvigy 5, Lori Bruhwiler6, Edward J. Dlugokencky6, Gustaf Hugelius 7, Ludovica D’Imperio8 and Bo Elberling 8 Methane emissions from organic-rich soils in the Arctic have bacteria (methanotrophs) and the remainder is mostly emitted into been extensively studied due to their potential to increase the atmosphere (Fig. 1a). The methanotrophs in these wet organic the atmospheric methane burden as permafrost thaws1–3. soils may be low-affinity methanotrophs (LAMs) that require However, this methane source might have been overestimated >600 ppm of methane (by moles) for their growth and mainte- without considering high-affinity methanotrophs (HAMs; nance23. But in dry mineral soils, the dominant methanotrophs are methane-oxidizing bacteria) recently identified in Arctic min- high-affinity methanotrophs (HAMs), which can survive and grow 4–7 eral soils . Herein we find that integrating the dynamics of at a level of atmospheric methane abundance ([CH4]atm) of about HAMs and methanogens into a biogeochemistry model8–10 1.8 ppm (Fig. 1b)24. that includes permafrost soil organic carbon dynamics3 leads Quantification of the previously underestimated HAM-driven −1 to the upland methane sink doubling (~5.5 Tg CH4 yr ) north of methane sink is needed to improve our understanding of Arctic 50 °N in simulations from 2000–2016. The increase is equiva- methane budgets. -
Geochemistry of Subglacial Lake Whillans, West Antarctica: Implications for Microbial Activity
5th International Conference on Polar & Alpine Microbiology, Big Sky, MT, USA, 2013 Geochemistry of subglacial Lake Whillans, West Antarctica: Implications for microbial activity. Mark Skidmore1, Andrew Mitchell2, Carlo Barbante3, Alex Michaud4, Trista Vick-Majors4, John Priscu4 1Earth Sciences, Montana State University, Bozeman, MT, USA, 2Geography and Earth Sciences, Aberystwyth University, Aberystwyth, UK, 3Institute for the Dynamics of Environmental Processes-CNR, University of Venice, Venice, Italy. 4Land Resources and Environmental Sciences, Montana State University, Bozeman, MT, USA. Subglacial Lake Whillans is located beneath the Whillans Ice Stream in West Antarctica. The lake is situated beneath 800 m of ice and ~ 70 km upstream of the grounding line where Whillans Ice Stream terminates into the Ross Sea. Water and sediment samples were recovered from the lake, using clean access drilling technologies, in January, 2013. Isotopic analysis of the lake waters indicates basal meltwater from the ice sheet as the dominant water source. Geochemical analysis of the lake waters reveal it is freshwater with total dissolved solids concentrations about 1/70th that of sea water. However, mineral weathering is a significant source of solute to the lake water with a contribution also from sea water. Nutrients N and P are present at micromolar concentrations. The sediment porewaters from shallow cores (~ 40 cm depth) of the subglacial lake sediments indicate increasing solute concentration with depth, with up to ~ five times greater solute concentrations than in the lake waters. Collectively the aqueous geochemistry indicates an environment favorable for microbial activity. Thus, microbially-driven mineral weathering appears likely beneath the Whillans Ice Stream, as has been demonstrated in other subglacial systems, including in subglacial sediments of the neighboring Kamb Ice Stream. -
7Th Grade February Break Packet.Pdf
__________________ ___________________ _________________ Read this story. Then answer questions 15 through 21. e narrator, Holling Hoodhood, has a crush on Meryl Lee Kowalski. Holling’s father has been honored earlier in the story by a local business group as the best businessman of 1967. Excerpt from e Wednesday Wars by Gary D. Schmidt 1 e following week the school board met to decide on the model for the new junior high school—which was probably why Mr. Kowalski had been spending all his time muttering “classical, classical, classical.” e meeting was to be at four o’clock in the high school administration building. Mr. Kowalski would present his plan and model, and then my father would present his plan and model, and then the school board would meet in private session to decide whether Kowalski and Associates or Hoodhood and Associates would be the architect for the new junior high school. 2 I know all of this because my father was making me come. It was time I started to learn the business, he said. I needed to see firsthand how competitive bidding worked. I needed to experience architectural presentations. I needed to see architecture as the blood sport that it truly was. 3 e meeting was in the public conference room, and when I got there aer school, the school board members were all sitting at the head table, studying the folders with architectural bids. Mr. Kowalski and my father were sitting at two of the high school desks—which made the whole thing seem a little weirder than it needed to be. -
Antarctic Primer
Antarctic Primer By Nigel Sitwell, Tom Ritchie & Gary Miller By Nigel Sitwell, Tom Ritchie & Gary Miller Designed by: Olivia Young, Aurora Expeditions October 2018 Cover image © I.Tortosa Morgan Suite 12, Level 2 35 Buckingham Street Surry Hills, Sydney NSW 2010, Australia To anyone who goes to the Antarctic, there is a tremendous appeal, an unparalleled combination of grandeur, beauty, vastness, loneliness, and malevolence —all of which sound terribly melodramatic — but which truly convey the actual feeling of Antarctica. Where else in the world are all of these descriptions really true? —Captain T.L.M. Sunter, ‘The Antarctic Century Newsletter ANTARCTIC PRIMER 2018 | 3 CONTENTS I. CONSERVING ANTARCTICA Guidance for Visitors to the Antarctic Antarctica’s Historic Heritage South Georgia Biosecurity II. THE PHYSICAL ENVIRONMENT Antarctica The Southern Ocean The Continent Climate Atmospheric Phenomena The Ozone Hole Climate Change Sea Ice The Antarctic Ice Cap Icebergs A Short Glossary of Ice Terms III. THE BIOLOGICAL ENVIRONMENT Life in Antarctica Adapting to the Cold The Kingdom of Krill IV. THE WILDLIFE Antarctic Squids Antarctic Fishes Antarctic Birds Antarctic Seals Antarctic Whales 4 AURORA EXPEDITIONS | Pioneering expedition travel to the heart of nature. CONTENTS V. EXPLORERS AND SCIENTISTS The Exploration of Antarctica The Antarctic Treaty VI. PLACES YOU MAY VISIT South Shetland Islands Antarctic Peninsula Weddell Sea South Orkney Islands South Georgia The Falkland Islands South Sandwich Islands The Historic Ross Sea Sector Commonwealth Bay VII. FURTHER READING VIII. WILDLIFE CHECKLISTS ANTARCTIC PRIMER 2018 | 5 Adélie penguins in the Antarctic Peninsula I. CONSERVING ANTARCTICA Antarctica is the largest wilderness area on earth, a place that must be preserved in its present, virtually pristine state. -
The Ratio of Methanogens to Methanotrophs and Water-Level Dynamics Drive Methane Exchange Velocity in a Temperate Kettle-Hole Peat Bog
Biogeosciences Discuss., https://doi.org/10.5194/bg-2019-116 Manuscript under review for journal Biogeosciences Discussion started: 23 April 2019 c Author(s) 2019. CC BY 4.0 License. The ratio of methanogens to methanotrophs and water-level dynamics drive methane exchange velocity in a temperate kettle-hole peat bog Camilo Rey-Sanchez1,4, Gil Bohrer1, Julie Slater2, Yueh-Fen Li3, Roger Grau-Andrés2, Yushan Hao2, 5 Virginia I. Rich3, & G. Matt Davies2 1Department of Civil and Environmental Engineering and Geodetic Science, The Ohio State University, Columbus, Ohio, 43210, USA 2School of Environment and Natural Resources, The Ohio State University, Columbus, Ohio, 43210, USA 3Department of Microbiology, The Ohio State University, Columbus, Ohio, 43210, USA 10 4Current address, Department of Environmental Science, Management and Policy, University of California- Berkeley, California, 94720, USA Correspondence to: Camilo Rey-Sanchez ([email protected]) 15 Abstract. Peatlands are a large source of methane (CH4) to the atmosphere, yet the uncertainty around the estimates of CH4 flux from peatlands is large. To better understand the spatial heterogeneity in temperate peatland CH4 emissions and their response to physical and biological drivers, we studied CH4 dynamics throughout the growing seasons of 2017 and 2018 in Flatiron Lake Bog, a kettle-hole peat bog in Ohio. The site is composed of six different hydro-biological zones: an open water zone, four concentric vegetation zones surrounding the open water, and a restored zone connected to the main bog by a narrow 20 channel. At each of these locations, we monitored water level (WL), CH4 pore-water concentration at different peat depths, CH4 fluxes from the ground and from representative plant species using chambers, and microbial community composition with focus here on known methanogens and methanotrophs. -
Methane Utilization in Methylomicrobium Alcaliphilum 20ZR: a Systems Approach Received: 8 September 2017 Ilya R
www.nature.com/scientificreports OPEN Methane utilization in Methylomicrobium alcaliphilum 20ZR: a systems approach Received: 8 September 2017 Ilya R. Akberdin1,2, Merlin Thompson1, Richard Hamilton1, Nalini Desai3, Danny Alexander3, Accepted: 22 January 2018 Calvin A. Henard4, Michael T. Guarnieri4 & Marina G. Kalyuzhnaya1 Published: xx xx xxxx Biological methane utilization, one of the main sinks of the greenhouse gas in nature, represents an attractive platform for production of fuels and value-added chemicals. Despite the progress made in our understanding of the individual parts of methane utilization, our knowledge of how the whole-cell metabolic network is organized and coordinated is limited. Attractive growth and methane-conversion rates, a complete and expert-annotated genome sequence, as well as large enzymatic, 13C-labeling, and transcriptomic datasets make Methylomicrobium alcaliphilum 20ZR an exceptional model system for investigating methane utilization networks. Here we present a comprehensive metabolic framework of methane and methanol utilization in M. alcaliphilum 20ZR. A set of novel metabolic reactions governing carbon distribution across central pathways in methanotrophic bacteria was predicted by in-silico simulations and confrmed by global non-targeted metabolomics and enzymatic evidences. Our data highlight the importance of substitution of ATP-linked steps with PPi-dependent reactions and support the presence of a carbon shunt from acetyl-CoA to the pentose-phosphate pathway and highly branched TCA cycle. The diverged TCA reactions promote balance between anabolic reactions and redox demands. The computational framework of C1-metabolism in methanotrophic bacteria can represent an efcient tool for metabolic engineering or ecosystem modeling. Climate change concerns linked to increasing concentrations of anthropogenic methane have spiked inter- est in biological methane utilization as a novel platform for improving ecological and human well-being1–4. -
(Antarctica) Glacial, Basal, and Accretion Ice
CHARACTERIZATION OF ORGANISMS IN VOSTOK (ANTARCTICA) GLACIAL, BASAL, AND ACCRETION ICE Colby J. Gura A Thesis Submitted to the Graduate College of Bowling Green State University in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE December 2019 Committee: Scott O. Rogers, Advisor Helen Michaels Paul Morris © 2019 Colby Gura All Rights Reserved iii ABSTRACT Scott O. Rogers, Advisor Chapter 1: Lake Vostok is named for the nearby Vostok Station located at 78°28’S, 106°48’E and at an elevation of 3,488 m. The lake is covered by a glacier that is approximately 4 km thick and comprised of 4 different types of ice: meteoric, basal, type 1 accretion ice, and type 2 accretion ice. Six samples were derived from the glacial, basal, and accretion ice of the 5G ice core (depths of 2,149 m; 3,501 m; 3,520 m; 3,540 m; 3,569 m; and 3,585 m) and prepared through several processes. The RNA and DNA were extracted from ultracentrifugally concentrated meltwater samples. From the extracted RNA, cDNA was synthesized so the samples could be further manipulated. Both the cDNA and the DNA were amplified through polymerase chain reaction. Ion Torrent primers were attached to the DNA and cDNA and then prepared to be sequenced. Following sequencing the sequences were analyzed using BLAST. Python and Biopython were then used to collect more data and organize the data for manual curation and analysis. Chapter 2: As a result of the glacier and its geographic location, Lake Vostok is an extreme and unique environment that is often compared to Jupiter’s ice-covered moon, Europa. -
Subglacial Lake Ellsworth CEE V2.Indd
Proposed Exploration of Subglacial Lake Ellsworth Antarctica Draft Comprehensive Environmental Evaluation February 2011 1 The cover art was created by first, second, and third grade students at The Village School, a Montessori school located in Waldwick, New Jersey. Art instructor, Bob Fontaine asked his students to create an interpretation of the work being done on The Lake Ellsworth Project and to create over 200 of their own imaginary microbes. This art project was part of The Village School’s art curriculum that links art with ongoing cultural work. 2 Contents Non Technical Summary .................................................4 Personnel ............................................................................................ 26 Chapter 1: Introduction ...................................................6 Power generation and fuel calculations ....................................... 27 Chapter 2: Description of proposed activity..................7 Vehicles ................................................................................................ 28 Background and justification ..............................................................7 Water and waste ...............................................................................28 The site ...................................................................................................8 Communications ............................................................................... 28 Chapter 3: Baseline conditions of Lake Ellsworth .........9 Transport of equipment -
Race Is on to Find Life Under Antarctic Ice Russia, U.S., and Britain Drill to Discover Microbes in Subglacial Lakes
Race Is On to Find Life Under Antarctic Ice Russia, U.S., and Britain drill to discover microbes in subglacial lakes. A person works at the drilling site atop Lake Ellsworth, Antarctica. Photograph courtesy Pete Bucktrout, British Antarctic Survey Marc Kaufman for National Geographic News Published December 18, 2012 A hundred years ago, two teams of explorers set out to be the first people ever to reach the South Pole. The race between Roald Amundsen of Norway and Robert Falcon Scott of Britain became the stuff of triumph, tragedy, and legend. (See rare pictures of Scott's expedition.) Today, another Antarctic drama is underway that has a similar daring and intensity—but very different stakes. Three unprecedented, major expeditions are underway to drill deep through the ice covering the continent and, researchers hope, penetrate three subglacial lakes not even known to exist until recently. The three players—Russia, Britain, and the United States—are all on the ice now and are in varying stages of their preparations. The first drilling was attempted last week by the British team at Lake Ellsworth, but mechanical problems soon cropped up in the unforgiving Antarctic cold, putting a temporary hold on their work. The key scientific goal of the missions: to discover and identify living organisms in Antarctica's dark, pristine, and hidden recesses. (See"Antarctica May Contain 'Oasis of Life.'") Scientists believe the lakes may well be home to the kind of "extreme" life that could eke out an existence on other planets or moons of our solar system, so finding them on Earth could help significantly in the search for life elsewhere. -
Subglacial Meltwater Supported Aerobic Marine Habitats During Snowball Earth
Subglacial meltwater supported aerobic marine habitats during Snowball Earth Maxwell A. Lechtea,b,1, Malcolm W. Wallacea, Ashleigh van Smeerdijk Hooda, Weiqiang Lic, Ganqing Jiangd, Galen P. Halversonb, Dan Asaele, Stephanie L. McColla, and Noah J. Planavskye aSchool of Earth Sciences, University of Melbourne, Parkville, VIC 3010, Australia; bDepartment of Earth and Planetary Science, McGill University, Montréal, QC, Canada H3A 0E8; cState Key Laboratory for Mineral Deposits Research, School of Earth Sciences and Engineering, Nanjing University, 210093 Nanjing, China; dDepartment of Geoscience, University of Nevada, Las Vegas, NV 89154; and eDepartment of Geology and Geophysics, Yale University, New Haven, CT 06511 Edited by Paul F. Hoffman, University of Victoria, Victoria, BC, Canada, and approved November 3, 2019 (received for review May 28, 2019) The Earth’s most severe ice ages interrupted a crucial interval in Cryogenian ice age. These marine chemical sediments are unique eukaryotic evolution with widespread ice coverage during the geochemical archives of synglacial ocean chemistry. To develop Cryogenian Period (720 to 635 Ma). Aerobic eukaryotes must have sur- a global picture of seawater redox state during extreme glaci- vived the “Snowball Earth” glaciations, requiring the persistence of ation, we studied 9 IF-bearing Sturtian glacial successions across 3 oxygenated marine habitats, yet evidence for these environments paleocontinents (Fig. 1): Congo (Chuos Formation, Namibia), is lacking. We examine iron formations within globally distributed Australia (Yudnamutana Subgroup), and Laurentia (Kingston Cryogenian glacial successions to reconstruct the redox state of the Peak Formation, United States). These IFs were selected for synglacial oceans. Iron isotope ratios and cerium anomalies from a analysis because they are well-preserved, and their depositional range of glaciomarine environments reveal pervasive anoxia in the environment can be reliably constrained. -
Environment and Processes of Subglacial Lake Whillans, West Antarctica
Environment and Processes of Subglacial Lake Whillans, West Antarctica Ross Powell1, Tim Hodson1, Jeremy Wei1, Slawek Tulaczyk2, Stefanie Brachfeld3, Isla Castañeda4, Rebecca Putkammer1, Reed Scherer1, and the WISSARD Science Team 1Department of Geology and Environmental Geosciences, Northern Illinois University 2Department of Earth and Planetary Sciences, University of California Santa Cruz 3Earth and Environmental Studies, Montclair State University 4Department of Geosciences, University of Massachusetts, Amherst Subglacial Lake Whillans (SLW) lies 800m below the low gradient, Whillans Ice Plain West Antarctica, upstream from where Whillans Ice Stream goes afloat into the Ross Ice Shelf. During 2013-14 season the WISSARD project made measurements in, and collected water and sediment samples from SLW. Sediment is typical subglacial till; a homogenized, structureless diamicton. Debris from local basal ice is likely not contributed to SLW by rainout because ice is theoretically below pressure melting. So lake floor diamicton likely was transported to SLW by deformation while the ice stream was grounded at the drill site both prior to lake formation and during lake “lowstands”. Satellite altimetry has shown SLW experiences short (~7 month) discharge events, lowering the ice surface and lake water level by between 1- 4m. Lake lowstands are separated by longer periods of gradual recharge, but over the period of many lowstands the ice stream is suspected to touch down and couple with the lake floor, potentially shearing new till into SLW. Subglacial hydrological diversions also may play a role in SLW history; if water is captured by another drainage basin, then the bed at SLW will also act as a till. The lack of sorted sediment (apart from a lamina of mud at the sediment-water interface) and erosional lags within sediment cores indicate water flow during discharge/recharge events has had a low current velocity with quiescent conditions in the lake.