{"dp_type": "Dataset", "free_text": "Bacteria"}
[{"awards": "2044924 Barrett, John", "bounds_geometry": ["POLYGON((161.70776367188 -77.519802097166,161.899475097661 -77.519802097166,162.091186523442 -77.519802097166,162.282897949223 -77.519802097166,162.474609375004 -77.519802097166,162.666320800785 -77.519802097166,162.858032226566 -77.519802097166,163.049743652347 -77.519802097166,163.241455078128 -77.519802097166,163.433166503909 -77.519802097166,163.62487792969 -77.519802097166,163.62487792969 -77.54867059480199,163.62487792969 -77.57753909243799,163.62487792969 -77.606407590074,163.62487792969 -77.63527608771,163.62487792969 -77.664144585346,163.62487792969 -77.69301308298199,163.62487792969 -77.72188158061799,163.62487792969 -77.750750078254,163.62487792969 -77.77961857589,163.62487792969 -77.808487073526,163.433166503909 -77.808487073526,163.241455078128 -77.808487073526,163.049743652347 -77.808487073526,162.858032226566 -77.808487073526,162.666320800785 -77.808487073526,162.474609375004 -77.808487073526,162.282897949223 -77.808487073526,162.091186523442 -77.808487073526,161.899475097661 -77.808487073526,161.70776367188 -77.808487073526,161.70776367188 -77.77961857589,161.70776367188 -77.750750078254,161.70776367188 -77.72188158061799,161.70776367188 -77.69301308298199,161.70776367188 -77.664144585346,161.70776367188 -77.63527608771,161.70776367188 -77.606407590074,161.70776367188 -77.57753909243799,161.70776367188 -77.54867059480199,161.70776367188 -77.519802097166))"], "date_created": "Wed, 03 Apr 2024 00:00:00 GMT", "description": "Microbial communities are the primary drivers of carbon cycling in the McMurdo Dry Valleys of Antarctica. Dense microbial mats, consisting mainly of photosynthetic cyanobacteria, occupy aquatic areas associated with streams and lakes. Other microbial communities also occur at lower densities as patchy surface biological soil crusts (biocrusts) across the terrestrial landscape. Multispectral satellite data have been used to model microbial mat abundance in high-density areas like stream and lake margins, but no previous studies had investigated the lower detection limits of biocrusts. Here, we describe remote sensing and field-based survey and sampling approaches to study the detectability and distribution of biocrusts in the McMurdo Dry Valleys. Using a combination of multi- and hyperspectral tools and spectral linear unmixing, we modeled the abundances of biocrust in eastern Taylor Valley. Our spectral approaches can detect low masses of biocrust material in laboratory microcosms down to biocrust concentrations of 1% by mass. These techniques also distinguish the spectra of biocrust from both surface rock and mineral signatures from orbit. We found that biocrusts are present throughout the soils of eastern Taylor Valley and are associated with diverse underlying soil communities. The densest biocrust communities identified in this study had total organic carbon 5x greater than the content of typical arid soils. The most productive biocrusts were located downslope of melting snowpacks in unique soil ecosystems that are distinct from the surrounding arid landscape. There are similarities between the snowpack and stream sediment communities (high diversity of soil invertebrates) as well as their ecosystem properties (e.g., persistence of liquid water, high transfer of available nutrients, lower salinity from flushing) compared to the typical arid terrestrial ecosystem of the dry valleys. Our approach extends the capability of orbital remote sensing of photosynthetic communities out of the aquatic margins and into the drier soils which comprise most of this landscape. This interdisciplinary work is critical for measuring and monitoring terrestrial carbon stocks and predicting future ecosystem dynamics in this currently water-limited but increasingly dynamic Antarctic landscape, which is particularly climate-sensitive and difficult to access.\r\n", "east": 163.62487792969, "geometry": ["POINT(162.666320800785 -77.664144585346)"], "keywords": "Antarctica; Carbon; Cryosphere; McMurdo Dry Valleys; Snow", "locations": "McMurdo Dry Valleys; Antarctica", "north": -77.519802097166, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "persons": "Barrett, John", "project_titles": null, "projects": null, "repositories": null, "science_programs": null, "south": -77.808487073526, "title": "Hyperspectral reflectance values and biophysicochemical properties of biocrusts and soils in the Fryxell Basin, McMurdo Dry Valleys, Antarctica", "uid": "601773", "west": 161.70776367188}, {"awards": "1543450 Countway, Peter", "bounds_geometry": ["POLYGON((-66 -63,-65.7 -63,-65.4 -63,-65.1 -63,-64.8 -63,-64.5 -63,-64.2 -63,-63.9 -63,-63.6 -63,-63.3 -63,-63 -63,-63 -63.3,-63 -63.6,-63 -63.9,-63 -64.2,-63 -64.5,-63 -64.8,-63 -65.1,-63 -65.4,-63 -65.7,-63 -66,-63.3 -66,-63.6 -66,-63.9 -66,-64.2 -66,-64.5 -66,-64.8 -66,-65.1 -66,-65.4 -66,-65.7 -66,-66 -66,-66 -65.7,-66 -65.4,-66 -65.1,-66 -64.8,-66 -64.5,-66 -64.2,-66 -63.9,-66 -63.6,-66 -63.3,-66 -63))"], "date_created": "Tue, 03 Jan 2023 00:00:00 GMT", "description": "Rates of heterotrophic bacterial production (BP) via 3H-Leu uptake were estimated for samples collected from Station E (Palmer Station, Antarctica) and associated incubation experiments. Rates of BP in seawater incubations greatly exceeded BP rates in the environment, likely due to stimulation of phytoplankton blooms and addition of DMSP in experimental treatments. \r\nMethods for determining BP were identical to those used by Palmer LTER investigators. References for the analytical methods used for these analyses are included in a secondary tab with the uploaded data. ", "east": -63.0, "geometry": ["POINT(-64.5 -64.5)"], "keywords": "3H-Leu; Antarctica; Bacteria; Biota; DMSP; Heterotrophic Bacterial Production; Palmer Station", "locations": "Palmer Station; Antarctica", "north": -63.0, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "persons": "Countway, Peter; Matrai, Patricia", "project_titles": "Microbial Community Structure and Expression of Functional Genes Involved in the Seasonal Cycling of DMSP in the Southern Ocean", "projects": [{"proj_uid": "p0010120", "repository": "USAP-DC", "title": "Microbial Community Structure and Expression of Functional Genes Involved in the Seasonal Cycling of DMSP in the Southern Ocean"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -66.0, "title": "Heterotrophic Bacterial Production Samples from Station E (Palmer Station, Antarctica) and Associated Incubation Experiments", "uid": "601644", "west": -66.0}, {"awards": "1543450 Countway, Peter", "bounds_geometry": ["POLYGON((-66 -63,-65.7 -63,-65.4 -63,-65.1 -63,-64.8 -63,-64.5 -63,-64.2 -63,-63.9 -63,-63.6 -63,-63.3 -63,-63 -63,-63 -63.3,-63 -63.6,-63 -63.9,-63 -64.2,-63 -64.5,-63 -64.8,-63 -65.1,-63 -65.4,-63 -65.7,-63 -66,-63.3 -66,-63.6 -66,-63.9 -66,-64.2 -66,-64.5 -66,-64.8 -66,-65.1 -66,-65.4 -66,-65.7 -66,-66 -66,-66 -65.7,-66 -65.4,-66 -65.1,-66 -64.8,-66 -64.5,-66 -64.2,-66 -63.9,-66 -63.6,-66 -63.3,-66 -63))"], "date_created": "Tue, 03 Jan 2023 00:00:00 GMT", "description": "Flow cytometry samples were collected from Station E (Palmer Station, Antarctica) and associated incubation experiments with Station E water. Samples were analyzed for Phytoplankton (\u003c20 um), Cryptophytes (\u003c20 um), Heterotrophic Nanoflagellates (\u003c20 um) and Total Bacteria. All flow cytometric analyses were performed at Bigelow Laboratory for Ocean Sciences. An overview of the analytical methods used for these samples is included in a secondary tab with the uploaded data.", "east": -63.0, "geometry": ["POINT(-64.5 -64.5)"], "keywords": "Antarctica; Palmer Station; Phytoplankton", "locations": "Palmer Station; Antarctica", "north": -63.0, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "persons": "Countway, Peter; Matrai, Patricia", "project_titles": "Microbial Community Structure and Expression of Functional Genes Involved in the Seasonal Cycling of DMSP in the Southern Ocean", "projects": [{"proj_uid": "p0010120", "repository": "USAP-DC", "title": "Microbial Community Structure and Expression of Functional Genes Involved in the Seasonal Cycling of DMSP in the Southern Ocean"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -66.0, "title": "Flow Cytometry Samples from Station E (Palmer Station, Antarctica) and Associated Incubation Experiments", "uid": "601647", "west": -66.0}, {"awards": "1644155 Twining, Benjamin", "bounds_geometry": ["POLYGON((-78.1833 -68.4333,-78.16499 -68.4333,-78.14668 -68.4333,-78.12837 -68.4333,-78.11006 -68.4333,-78.09175 -68.4333,-78.07344 -68.4333,-78.05513 -68.4333,-78.03682 -68.4333,-78.01851 -68.4333,-78.0002 -68.4333,-78.0002 -68.43664,-78.0002 -68.43998,-78.0002 -68.44332,-78.0002 -68.44666000000001,-78.0002 -68.45,-78.0002 -68.45334,-78.0002 -68.45668,-78.0002 -68.46002,-78.0002 -68.46336000000001,-78.0002 -68.4667,-78.01851 -68.4667,-78.03682 -68.4667,-78.05513 -68.4667,-78.07344 -68.4667,-78.09175 -68.4667,-78.11006 -68.4667,-78.12837 -68.4667,-78.14668 -68.4667,-78.16499 -68.4667,-78.1833 -68.4667,-78.1833 -68.46336000000001,-78.1833 -68.46002,-78.1833 -68.45668,-78.1833 -68.45334,-78.1833 -68.45,-78.1833 -68.44666000000001,-78.1833 -68.44332,-78.1833 -68.43998,-78.1833 -68.43664,-78.1833 -68.4333))"], "date_created": "Mon, 12 Dec 2022 00:00:00 GMT", "description": "Varying depth samples from Ace, Deep, \u0026 Organic Lake were obtained between 2013-2014. These samples were size fractionated by filtration for metagenomic analyses. Viral and bacterial abundances were determine on the filtrate fractions by flow cytometric analysis. Glutaraldehyde-fixed samples were stained with SYBR Green I fluorescence dye and virus-like particle (VLP) and bacteria-like cell (BLC) populations were discriminated based on green fluorescence and side scatter flow cytometry signals. Several distinct VLP and BLC populations where enumerated from Ace Lake and Organic Lake samples that revealed temporal and depth differences. Discrete VLP and BLC populations could not be discerned from Deep Lake samples. These files include the original flow cytometry particle counts (raw data), the gating templates used to count VLP and BLC populations (analysis_templates), and the resulting particle counts (analyzed).", "east": -78.0002, "geometry": ["POINT(-78.09175 -68.45)"], "keywords": "Ace Lake; Antarctica; Deep Lake; Organic Lake; Vestfold Hills", "locations": "Antarctica; Vestfold Hills; Ace Lake; Deep Lake; Organic Lake; Antarctica", "north": -68.4333, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "persons": "Twining, Benjamin; Martinez-Martinez, Joaquin", "project_titles": "Viral control of microbial communities in Antarctic lakes", "projects": [{"proj_uid": "p0010237", "repository": "USAP-DC", "title": "Viral control of microbial communities in Antarctic lakes"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -68.4667, "title": "Flow cytometry enumeration of virus-like and bacteria-like abundance in Ace, Deep, \u0026 Organic lakes (Antarctica)", "uid": "601626", "west": -78.1833}, {"awards": "0944150 Hall, Brenda", "bounds_geometry": ["POLYGON((163.5 -77.3,163.65 -77.3,163.8 -77.3,163.95 -77.3,164.1 -77.3,164.25 -77.3,164.4 -77.3,164.55 -77.3,164.7 -77.3,164.85 -77.3,165 -77.3,165 -77.39,165 -77.48,165 -77.57,165 -77.66,165 -77.75,165 -77.84,165 -77.93,165 -78.02,165 -78.11,165 -78.2,164.85 -78.2,164.7 -78.2,164.55 -78.2,164.4 -78.2,164.25 -78.2,164.1 -78.2,163.95 -78.2,163.8 -78.2,163.65 -78.2,163.5 -78.2,163.5 -78.11,163.5 -78.02,163.5 -77.93,163.5 -77.84,163.5 -77.75,163.5 -77.66,163.5 -77.57,163.5 -77.48,163.5 -77.39,163.5 -77.3))"], "date_created": "Wed, 20 Apr 2022 00:00:00 GMT", "description": "This dataset contains radiocarbon dates of benthic algal (cyanobacterial) mats within moraines associated with Ross Sea drift on the headlands of the Royal Society Range and covers the time period ~12-20 ka.", "east": 165.0, "geometry": ["POINT(164.25 -77.75)"], "keywords": "Antarctica; Last Glacial Maximum; McMurdo Sound; Radiocarbon Dates; Ross Sea Drift; Royal Society Range", "locations": "Royal Society Range; Royal Society Range; Ross Sea Drift; McMurdo Sound; Antarctica", "north": -77.3, "nsf_funding_programs": "Antarctic Glaciology", "persons": "Hall, Brenda", "project_titles": "Sensitivity of the Antarctic Ice Sheet to Climate Change over the Last Two Glacial/Interglacial Cycles", "projects": [{"proj_uid": "p0010302", "repository": "USAP-DC", "title": "Sensitivity of the Antarctic Ice Sheet to Climate Change over the Last Two Glacial/Interglacial Cycles"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -78.2, "title": "Royal Society Range Headland Moraine Belt Radiocarbon Data", "uid": "601555", "west": 163.5}, {"awards": "1947040 Postlethwait, John", "bounds_geometry": ["POLYGON((-63.1 -63.9,-63.02 -63.9,-62.94 -63.9,-62.86 -63.9,-62.78 -63.9,-62.7 -63.9,-62.62 -63.9,-62.54 -63.9,-62.46 -63.9,-62.38 -63.9,-62.3 -63.9,-62.3 -64.01,-62.3 -64.12,-62.3 -64.23,-62.3 -64.34,-62.3 -64.45,-62.3 -64.56,-62.3 -64.67,-62.3 -64.78,-62.3 -64.89,-62.3 -65,-62.38 -65,-62.46 -65,-62.54 -65,-62.62 -65,-62.7 -65,-62.78 -65,-62.86 -65,-62.94 -65,-63.02 -65,-63.1 -65,-63.1 -64.89,-63.1 -64.78,-63.1 -64.67,-63.1 -64.56,-63.1 -64.45,-63.1 -64.34,-63.1 -64.23,-63.1 -64.12,-63.1 -64.01,-63.1 -63.9))"], "date_created": "Mon, 14 Mar 2022 00:00:00 GMT", "description": "Metagenomic analyses of apparently healthy and tumor samples using Kaiju v.1.7.4 software and a custom database generated from NCBI NR database retrieved on July 24th, 2021, and containing all viruses, archaea, and bacteria sequences, as well as microbial eukaryotes and Trematomus spp. fish sequences.", "east": -62.3, "geometry": ["POINT(-62.7 -64.45)"], "keywords": "Alveolata; Antarctica; Antarctic Peninsula; Notoxcellia Coronata; Notoxcellia Picta; Perkinsozoa; Xcellidae", "locations": "Antarctic Peninsula; Antarctica", "north": -63.9, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "persons": "Desvignes, Thomas; Fontenele, Rafaela S. ; Kraberger, Simona ; Varsani, Arvind; Postlethwait, John", "project_titles": "EAGER: Origin and Physiological Consequences of a Neoplasm Outbreak in Antarctic Fish ", "projects": [{"proj_uid": "p0010221", "repository": "USAP-DC", "title": "EAGER: Origin and Physiological Consequences of a Neoplasm Outbreak in Antarctic Fish "}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -65.0, "title": "Metagenomic analysis of apparently healthy and tumor samples using Kaiju software ", "uid": "601537", "west": -63.1}, {"awards": "1656344 Bowman, Jeff", "bounds_geometry": ["POLYGON((-64.1 -64.75,-64.08 -64.75,-64.06 -64.75,-64.04 -64.75,-64.02 -64.75,-64 -64.75,-63.98 -64.75,-63.96 -64.75,-63.94 -64.75,-63.92 -64.75,-63.9 -64.75,-63.9 -64.775,-63.9 -64.8,-63.9 -64.825,-63.9 -64.85,-63.9 -64.875,-63.9 -64.9,-63.9 -64.925,-63.9 -64.95,-63.9 -64.975,-63.9 -65,-63.92 -65,-63.94 -65,-63.96 -65,-63.98 -65,-64 -65,-64.02 -65,-64.04 -65,-64.06 -65,-64.08 -65,-64.1 -65,-64.1 -64.975,-64.1 -64.95,-64.1 -64.925,-64.1 -64.9,-64.1 -64.875,-64.1 -64.85,-64.1 -64.825,-64.1 -64.8,-64.1 -64.775,-64.1 -64.75))"], "date_created": "Mon, 04 Feb 2019 00:00:00 GMT", "description": "This dataset contains bacterial production, primary production, chlorophyll biomass, and photosynthetic parameters for samples archived in NCBI SRA as SUB4579142.", "east": -63.9, "geometry": ["POINT(-64 -64.875)"], "keywords": "Antarctic; Antarctica; Bacteria; Bacteria Production; Biota; Chlorophyll; LTER Palmer Station; Primary Production; Sea Ice; Southern Ocean", "locations": "Antarctic; Antarctica; Southern Ocean", "north": -64.75, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "persons": "Bowman, Jeff", "project_titles": "A Preliminary Assessment of the Influence of Ice Cover on Microbial Carbon and Energy Acquisition during the Antarctic Winter-spring Seasonal Transition", "projects": [{"proj_uid": "p0010003", "repository": "USAP-DC", "title": "A Preliminary Assessment of the Influence of Ice Cover on Microbial Carbon and Energy Acquisition during the Antarctic Winter-spring Seasonal Transition"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -65.0, "title": "Metadata accompanying BioProject SUB4579142", "uid": "601153", "west": -64.1}, {"awards": "1141993 Rich, Jeremy", "bounds_geometry": ["POINT(-64.05 -64.77)"], "date_created": "Mon, 12 Jun 2017 00:00:00 GMT", "description": "From winter to late summer during the 2013-2014 season at Palmer Station, Antarctica, we collected weekly to bi-weekly samples of the seawater intake to measure changes in bacterial community composition, based on sequencing 16S rRNA genes. Along with the sequences, we collected data on environmental parameters in the samples (chlorophyll a, bacterial production, salinity, nutrients, bacterial cell numbers, and particulate organic carbon and nitrogen).", "east": -64.05, "geometry": ["POINT(-64.05 -64.77)"], "keywords": "Antarctica; Antarctic Peninsula; Bacteria; Biota; Genetic; Geochemistry; Palmer Station; Sample/collection Description; Sample/Collection Description; Sea Water; Southern Ocean", "locations": "Antarctic Peninsula; Palmer Station; Antarctica; Southern Ocean", "north": -64.77, "nsf_funding_programs": null, "persons": "Rich, Jeremy", "project_titles": "Collaborative Research: Microbial Community Assembly in Coastal Waters of the Western Antarctic Peninsula", "projects": [{"proj_uid": "p0000409", "repository": "USAP-DC", "title": "Collaborative Research: Microbial Community Assembly in Coastal Waters of the Western Antarctic Peninsula"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -64.77, "title": "Seasonal Succession of Bacterial Communities in Coastal Waters of the Western Antarctic Peninsula", "uid": "601032", "west": -64.05}, {"awards": "0838996 Hollibaugh, James", "bounds_geometry": ["POLYGON((-79 -63,-77.5 -63,-76 -63,-74.5 -63,-73 -63,-71.5 -63,-70 -63,-68.5 -63,-67 -63,-65.5 -63,-64 -63,-64 -63.8,-64 -64.6,-64 -65.4,-64 -66.2,-64 -67,-64 -67.8,-64 -68.6,-64 -69.4,-64 -70.2,-64 -71,-65.5 -71,-67 -71,-68.5 -71,-70 -71,-71.5 -71,-73 -71,-74.5 -71,-76 -71,-77.5 -71,-79 -71,-79 -70.2,-79 -69.4,-79 -68.6,-79 -67.8,-79 -67,-79 -66.2,-79 -65.4,-79 -64.6,-79 -63.8,-79 -63))"], "date_created": "Wed, 01 Jan 2014 00:00:00 GMT", "description": "Ammonia oxidation is the first step in the conversion of regenerated nitrogen to dinitrogen gas, a 3-step pathway mediated by 3 distinct guilds of bacteria and archaea. Ammonia oxidation and the overall process of nitrification-denitrification have received relatively little attention in polar oceans where the effects of climate change on biogeochemical rates are likely to be pronounced. Previous work on Ammonia Oxidizing Archaea (AOA) in the Palmer LTER study area West of the Antarctic Peninsula (WAP), has suggested strong vertical segregation of crenarchaeote metabolism, with the \u0027winter water\u0027 (WW, ~50-100 m depth range) dominated by non-AOA crenarchaeotes, while Crenarchaeota populations in the \u0027circumpolar deep water\u0027 (CDW), which lies immediately below the winter water (150-3500 m), are dominated by AOA. Analysis of a limited number of samples from the Arctic Ocean did not reveal a comparable vertical segregation of AOA, and suggested that AOA and Crenarchaeota abundance is much lower there than in the Antarctic. These findings led to 3 hypotheses that will be tested in this project: 1) the apparent low abundance of Crenarchaeota and AOA in Arctic Ocean samples may be due to spatial or temporal variability in populations; 2) the WW population of Crenarchaeota in the WAP is dominated by a heterotroph; 3) the WW population of Crenarchaeota in the WAP \u0027grows in\u0027 during spring and summer after this water mass forms.\n\nThe study will contribute substantially to understanding an important aspect of the nitrogen cycle in the Palmer LTER (Long Term Ecological Research) study area by providing insights into the ecology and physiology of AOA. The natural segregation of crenarchaeote phenotypes in waters of the WAP, coupled with metagenomic studies in progress in the same area by others (A. Murray, H. Ducklow), offers the possibility of major breakthroughs in understanding of the metabolic capabilities of these organisms. This knowledge is needed to model how water column nitrification will respond to changes in polar ecosystems accompanying global climate change. The Principal Investigator will participate fully in the education and outreach efforts of the Palmer LTER, including making highlights of our findings available for posting to their project web site and participating in outreach (for example, Schoolyard LTER). The research also will involve undergraduates (including the field work if possible) and will support high school interns in the P.I.\u0027s laboratory over the summer.\n", "east": -64.0, "geometry": ["POINT(-71.5 -67)"], "keywords": "Biota; Chemistry:fluid; Chemistry:Fluid; LMG1006; LMG1101; LTER Palmer Station; Oceans; Southern Ocean", "locations": "Southern Ocean", "north": -63.0, "nsf_funding_programs": null, "persons": "Hollibaugh, James T.", "project_titles": "Ammonia Oxidation Versus Heterotrophy in Crenarchaeota Populations from Marine Environments West of the Antarctic Peninsula", "projects": [{"proj_uid": "p0000359", "repository": "USAP-DC", "title": "Ammonia Oxidation Versus Heterotrophy in Crenarchaeota Populations from Marine Environments West of the Antarctic Peninsula"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -71.0, "title": "Ammonia Oxidation Versus Heterotrophy in Crenarchaeota Populations from Marine Environments West of the Antarctic Peninsula", "uid": "600105", "west": -79.0}, {"awards": "0739783 Junge, Karen", "bounds_geometry": ["POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))"], "date_created": "Tue, 01 Jan 2013 00:00:00 GMT", "description": "The mechanisms enabling bacteria to be metabolically active at very low temperatures are of considerable importance to polar microbial ecology, astrobiology, climate and cryopreservation. This research program has two main objectives. The first is to investigate metabolic activities and gene expression of polar marine psychrophilic bacteria when confronted with freezing conditions at temperatures above the eutectic of seawater (\u003c54C) to unveil cold adaptation mechanisms with relevance to wintertime sea-ice ecology. The second objective is to discern if psychrophilic processes of leucine incorporation into proteins, shown to occur to -196C, amount to metabolic activity providing for the survival of cells or are merely biochemical reactions still possible in flash-frozen samples without any effect on survival. We will examine extracellular and intracellular processes of psychrophilic activity above and below the eutectic by (i) determining the temperature range of metabolic activities such as DNA synthesis, carbon utilization, respiration and ATP generation using radioactive tracer technology, including a control at liquid helium temperature (-268.9C), (ii) analyzing gene expression in ice using whole genome and microarray analyses and iii) examining the role of exopolymeric substances (EPS) and ice micro-physics for the observed activity using an in-situ microscopy technique. Results of the proposed research can be expected to aid in the determination of cellular and genetic strategies that allow cells to maintain activity at extremely low temperatures within an icy matrix and/or to resume activity again when more growth-permissive conditions are encountered. The research is an interdisciplinary collaboration involving three different institutions with participants in Oceanography, Genomics, and Geophysical Sciences. The proposed activity will support the beginning professional career of a female researcher and will serve as the basis for several undergraduate student laboratory projects.", "east": 180.0, "geometry": ["POINT(0 -89.999)"], "keywords": "Antarctica; Biota; Microbiology; Oceans; Sea Ice; Southern Ocean", "locations": "Southern Ocean; Antarctica", "north": -60.0, "nsf_funding_programs": null, "persons": "Junge, Karen", "project_titles": "Metabolic Activities and Gene Expression of Marine Psychrophiles in Cold Ice", "projects": [{"proj_uid": "p0000673", "repository": "USAP-DC", "title": "Metabolic Activities and Gene Expression of Marine Psychrophiles in Cold Ice"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -90.0, "title": "Metabolic Activities and Gene Expression of Marine Psychrophiles in Cold Ice", "uid": "600083", "west": -180.0}, {"awards": "0739681 Murray, Alison; 0739698 Doran, Peter", "bounds_geometry": ["POINT(161.931 -77.3885)"], "date_created": "Tue, 01 Jan 2013 00:00:00 GMT", "description": "Lake Vida is the largest lake of the McMurdo Dry Valleys, with an approximately 20 m ice cover overlaying a brine of unknown depth with at least 7 times seawater salinity and temperatures below -10 degrees C year-round. Samples of brine collected from ice above the main water body contain 1) the highest nitrous oxide levels of any natural water body on Earth, 2) unusual geochemistry including anomalously high ammonia and iron concentrations, 3) high microbial counts with an unusual proportion (99%) of ultramicrobacteria. The microbial community is unique even compared to other Dry Valley Lakes. The research proposes to enter, for the first time the main brine body below the thick ice of Lake Vida and perform in situ measurements, collect samples of the brine column, and collect sediment cores from the lake bottom for detailed geochemical and microbiological analyses. The results will allow the characterization of present and past life in the lake, assessment of modern and past sedimentary processes, and determination of the lake\u0027s history. The research will be conducted by a multidisciplinary team that will uncover the biogeochemical processes associated with a non-photosynthetic microbial community isolated for a significant period of time. This research will address diversity, adaptive mechanisms and evolutionary processes in the context of the physical evolution of the environment of Lake Vida. Results will be widely disseminated through publications, presentations at national and international meetings, through the Subglacial Antarctic Lake Exploration (SALE) web site and the McMurdo LTER web site. The research will support three graduate students and three undergraduate research assistants. The results will be incorporated into a new undergraduate biogeosciences course at the University of Illinois at Chicago which has an extremely diverse student body, dominated by minorities.", "east": 161.931, "geometry": ["POINT(161.931 -77.3885)"], "keywords": "Antarctica; Biota; Carbon-14; Chemistry:fluid; Chemistry:Fluid; Chemistry:ice; Chemistry:Ice; Dry Valleys; Geochronology; Ice Core Records; Lake Vida; Microbiology", "locations": "Dry Valleys; Lake Vida; Antarctica", "north": -77.3885, "nsf_funding_programs": null, "persons": "Murray, Alison", "project_titles": "Collaborative Research: Geochemistry and Microbiology of the Extreme Aquatic Environment in Lake Vida, East Antarctica", "projects": [{"proj_uid": "p0000485", "repository": "USAP-DC", "title": "Collaborative Research: Geochemistry and Microbiology of the Extreme Aquatic Environment in Lake Vida, East Antarctica"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -77.3885, "title": "Geochemistry and Microbiology of the Extreme Aquatic Environment in Lake Vida, East Antarctica", "uid": "600080", "west": 161.931}, {"awards": "0739648 Cary, Stephen", "bounds_geometry": ["POINT(163 -77.5)"], "date_created": "Tue, 01 Jan 2013 00:00:00 GMT", "description": "The glacial streams of the McMurdo Dry Valleys have extensive cyanobacterial mats that are a probable source of fixed C and N to the Valleys. The research will examine the interplay between the microbial mats in the ephemeral glacial streams and the microbiota of the hyporheic soils (wetted soil zone) underlying and adjacent to those mats. It is hypothesized that the mats are important sources of organic carbon and fixed nitrogen for the soil communities of the hyporheic zone, and release dissolved organic carbon (DOC) and nitrogen (DON) that serves the entire Dry Valley ecosystem. Field efforts will entail both observational and experimental components. Direct comparisons will be made between the mats and microbial populations underlying naturally rehydrated and desiccated mat areas, and between mat areas in the melt streams of the Adams and Miers Glaciers in Miers Valley. Both physiological and phylogenetic indices of the soil microbiota will be examined. Observations will include estimates of rates of mat carbon and nitrogen fixation, soil respiration and leucine and thymidine uptake (as measures of protein \u0026 DNA synthesis, respectively) by soil bacteria, bacterial densities and their molecular ecology. Experimental manipulations will include experimental re-wetting of soils and observations of the time course of response of the microbial community. The research will integrate modern molecular genetic approaches (ARISA-DNA fingerprinting and ultra deep 16S rDNA microbial phylogenetic analysis) with geochemistry to study the diversity, ecology, and function of microbial communities that thrive in these extreme environments. The broader impacts of the project include research and educational opportunities for graduate students and a postdoctoral associate. The P.I.s will involve undergraduates as work-study students and in REU programs, and will participate in educational and outreach programs.", "east": 163.0, "geometry": ["POINT(163 -77.5)"], "keywords": "Antarctica; Biota; Cell Counts; Dry Valleys; Microbiology", "locations": "Dry Valleys; Antarctica", "north": -77.5, "nsf_funding_programs": null, "persons": "Cary, S. Craig", "project_titles": "Collaborative Research: Biogeochemistry of Cyanobactrial Mats and Hyporheic Zone Microbes in McMurdo Dry Valley Glacial Meltwater Streams", "projects": [{"proj_uid": "p0000476", "repository": "USAP-DC", "title": "Collaborative Research: Biogeochemistry of Cyanobactrial Mats and Hyporheic Zone Microbes in McMurdo Dry Valley Glacial Meltwater Streams"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -77.5, "title": "Biogeochemistry of Cyanobactrial Mats and Hyporheic Zone Microbes in McMurdo Dry Valley Glacial Meltwater Streams", "uid": "600079", "west": 163.0}, {"awards": "0801392 Swanson, Brian", "bounds_geometry": ["POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))"], "date_created": "Fri, 01 Jan 2010 00:00:00 GMT", "description": "The primary objective of this research is to investigate polar marine psychrophilic bacteria for their potential to nucleate ice using a combination of microbiological, molecular biological and atmospheric science approaches in the laboratory. Very little is known about how psychrophiles interact and cope with ice or their adaptations to conditions of extreme cold and salinity. This work will involve a series of laboratory experiments using a novel freeze-tube technique for assaying freezing spectra which will provide quantitative information on: (i) the temperature-dependent freezing rates for heterogeneously frozen droplets containing sea-ice bacteria, (ii) the proportional occurrence of ice-nucleation activity versus anti-freeze activity among sea-ice bacterial isolates and (iii) the temperature-dependent freezing rates of bacteria with ice-nucleation activity grown at a range of temperatures and salinities. The compound(s) responsible for the observed activity will be identified, which is an essential step towards the development of an in-situ bacterial ice-nucleation detection assay that can be applied in the field to Antarctic water and cloud samples. One of the goals of this work is to better understand survival and cold adaptation processes of polar marine bacteria confronted with freezing conditions in sea ice. Since sea ice strongly impacts polar, as well as the global climates, this research is of significant interest because it will also provide data for accessing the importance of bacterial ice nucleation in the formation of sea ice. These measurements of ice-nucleation rates will be the first high-resolution measurements for psychrophilic marine bacteria. Another goal is to better understand the impact of bacterial ice initiation processes in polar clouds by making high-resolution measurements of nucleation rates for cloud bacteria found over Arctic and Antarctic regions. Initial measurements indicate these bacteria nucleate ice at warmer temperatures and the effect in polar regions may be quite important, since ice can strongly impact cloud dynamics, cloud radiative properties, precipitation formation, and cloud chemistry. If these initial measurements are confirmed, the data collected here will be important for improving the understanding of polar cloud processes and models. A third goal is to better understand the molecular basis of marine bacterial ice nucleation by characterizing the ice-nucleation compound and comparing it with those of known plant-derived ice-nucleating bacteria, which are the only ice-nucleating bacteria examined in detail to date. The proposed activity will support the beginning academic career of a post-doctoral researcher and will serve as the basis for several undergraduate student laboratory projects. Results from this research will be widely published in various scientific journals and outreach venues.", "east": 180.0, "geometry": ["POINT(0 -89.999)"], "keywords": "Biota; Microbiology; Oceans; Raman Spectroscopy; Sea Ice; Sea Surface; Southern Ocean", "locations": "Sea Surface; Southern Ocean", "north": -60.0, "nsf_funding_programs": null, "persons": "Swanson, Brian", "project_titles": "Ice Nucleation by Marine Psychrophiles", "projects": [{"proj_uid": "p0000195", "repository": "USAP-DC", "title": "Ice Nucleation by Marine Psychrophiles"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -90.0, "title": "Ice Nucleation by Marine Psychrophiles", "uid": "600087", "west": -180.0}, {"awards": "0230276 Ward, Bess", "bounds_geometry": ["POLYGON((162 -77.2,162.16 -77.2,162.32 -77.2,162.48 -77.2,162.64 -77.2,162.8 -77.2,162.96 -77.2,163.12 -77.2,163.28 -77.2,163.44 -77.2,163.6 -77.2,163.6 -77.26,163.6 -77.32,163.6 -77.38,163.6 -77.44,163.6 -77.5,163.6 -77.56,163.6 -77.62,163.6 -77.68,163.6 -77.74,163.6 -77.8,163.44 -77.8,163.28 -77.8,163.12 -77.8,162.96 -77.8,162.8 -77.8,162.64 -77.8,162.48 -77.8,162.32 -77.8,162.16 -77.8,162 -77.8,162 -77.74,162 -77.68,162 -77.62,162 -77.56,162 -77.5,162 -77.44,162 -77.38,162 -77.32,162 -77.26,162 -77.2))"], "date_created": "Thu, 01 Jan 2009 00:00:00 GMT", "description": "Denitrification is the main process by which fixed nitrogen is lost from ecosystems and the regulation of this process may directly affect primary production and carbon cycling over short and long time scales. Previous investigations of the role of bioactive metals in regulating denitrification in bacteria from permanently ice-covered Lake Bonney in the Taylor Valley of East Antarctica indicated that denitrifying bacteria can be negatively affected by metals such as copper, iron, cadmium, lead, chromium, nickel, silver and zinc; and that there is a distinct difference in denitrifying activity between the east and west lobes of the lake. \n\nLow iron concentrations were found to exacerbate the potential toxicity of the other metals, while silver has the potential to specifically inhibit denitrification because of its ability to interfere with copper binding in redox proteins, such as nitrite reductase and nitrous oxide reductase. High silver concentrations might prevent the functioning of nitrous oxide reductase in the same way that simple copper limitation does, thereby causing the buildup of nitrous oxide and resulting in a nonfunctional nitrogen cycle. Other factors, such as oxygen concentration, are likely also to affect bacterial activity in Lake Bonney.\n\nThis project will investigate silver toxicity, general metal toxicity and oxygen concentration to determine their effect on denitrification in the lake by using a suite of \u0027sentinel\u0027 strains of denitrifying bacteria (isolated from the lake) incubated in Lake Bonney water and subjected to various treatments. The physiological responses of these strains to changes in metal and oxygen concentration will be quantified by flow cytometric detection of single cell molecular probes whose sensitivity and interpretation have been optimized for the sentinel strains. Understanding the relationships between metals and denitrification is expected to enhance our understanding of not only Lake Bonney\u0027s unusual nitrogen cycle, but more generally, of the potential role of metals in the regulation of microbial nitrogen transformations. The broader impacts of this work include not only a better understanding of regional biogeochemistry and global perspectives on these processes; but also the training of graduate students and a substantial outreach effort for school children.", "east": 163.6, "geometry": ["POINT(162.8 -77.5)"], "keywords": "Antarctica; Biota; CTD Data; Dry Valleys; Lake Bonney; Lake Vanda; Microbiology; Taylor Valley", "locations": "Dry Valleys; Lake Bonney; Lake Vanda; Taylor Valley; Antarctica", "north": -77.2, "nsf_funding_programs": null, "persons": "Ward, Bess", "project_titles": "Collaborative Research: What Limits Denitrification and Bacterial Growth in Lake Bonney, Taylor Valley, Antarctica?", "projects": [{"proj_uid": "p0000223", "repository": "USAP-DC", "title": "Collaborative Research: What Limits Denitrification and Bacterial Growth in Lake Bonney, Taylor Valley, Antarctica?"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -77.8, "title": "What Limits Denitrification and Bacterial Growth in Lake Bonney, Taylor Valley, Antarctica?", "uid": "600033", "west": 162.0}, {"awards": "0127022 Jeffrey, Wade", "bounds_geometry": ["POLYGON((159.8 -43.3,161.8 -43.3,163.8 -43.3,165.8 -43.3,167.8 -43.3,169.8 -43.3,171.8 -43.3,173.8 -43.3,175.8 -43.3,177.8 -43.3,179.8 -43.3,179.8 -45.65,179.8 -48,179.8 -50.35,179.8 -52.7,179.8 -55.05,179.8 -57.4,179.8 -59.75,179.8 -62.1,179.8 -64.45,179.8 -66.8,177.8 -66.8,175.8 -66.8,173.8 -66.8,171.8 -66.8,169.8 -66.8,167.8 -66.8,165.8 -66.8,163.8 -66.8,161.8 -66.8,159.8 -66.8,159.8 -64.45,159.8 -62.1,159.8 -59.75,159.8 -57.4,159.8 -55.05,159.8 -52.7,159.8 -50.35,159.8 -48,159.8 -45.65,159.8 -43.3))", "POLYGON((167 -74.4,168.36 -74.4,169.72 -74.4,171.08 -74.4,172.44 -74.4,173.8 -74.4,175.16 -74.4,176.52 -74.4,177.88 -74.4,179.24 -74.4,180.6 -74.4,180.6 -74.735,180.6 -75.07,180.6 -75.405,180.6 -75.74,180.6 -76.075,180.6 -76.41,180.6 -76.745,180.6 -77.08,180.6 -77.415,180.6 -77.75,179.24 -77.75,177.88 -77.75,176.52 -77.75,175.16 -77.75,173.8 -77.75,172.44 -77.75,171.08 -77.75,169.72 -77.75,168.36 -77.75,167 -77.75,167 -77.415,167 -77.08,167 -76.745,167 -76.41,167 -76.075,167 -75.74,167 -75.405,167 -75.07,167 -74.735,167 -74.4))"], "date_created": "Tue, 01 Jan 2008 00:00:00 GMT", "description": "Data from five research cruises from OPP grant entitled \"Interactive Effects of UV and Vertical Mixing on Phytoplankton and Bacterial Productivity of Ross Sea Phaeocystis Bloom (OPP0127022). The first two cruises were ships of opportunity cruises in the Pacific Ocean, the first collecting data between Valapariso, Chile and San Diego, CA (October 2002). The second and third cruises combined to provide data in a transect from 70 N to 68 S latitude in the Pacific ocean (August - November 2003). The remaining two cruises were to the Ross Sea, the first in December 2004 - January 2005 and the last from October - November 2005. Data presented include microbial biomass (bacterial direct counts) and chlorophyll a concentrations, bacterial production (as leucine or thymidine incorporation), solar irradiance data, CTD profiles, and one set of under water diffuse attenuation coefficients of for the Ross Sea.", "east": 180.6, "geometry": ["POINT(169.8 -55.05)", "POINT(173.8 -76.075)"], "keywords": "Biota; Chemistry:fluid; Chemistry:Fluid; CTD Data; Microbiology; Oceans; Phytoplankton; Ross Sea; Southern Ocean", "locations": "Ross Sea; Southern Ocean", "north": -43.3, "nsf_funding_programs": null, "persons": "Jeffrey, Wade H.", "project_titles": "Collaborative Proposal: Interactive Effects of UV Radiation and Vertical Mixing on Phytoplankton and Bacterial Productivity of Ross See Phaeocystis Blooms", "projects": [{"proj_uid": "p0000578", "repository": "USAP-DC", "title": "Collaborative Proposal: Interactive Effects of UV Radiation and Vertical Mixing on Phytoplankton and Bacterial Productivity of Ross See Phaeocystis Blooms"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -77.75, "title": "Interactive Effects of UV Radiation and Vertical Mixing on Phytoplankton and Bacterial Productivity of Ross Sea Phaeocystis Blooms", "uid": "600029", "west": 159.8}, {"awards": "0536870 Rogers, Scott", "bounds_geometry": ["POINT(106.8 -72.4667)"], "date_created": "Tue, 01 Jan 2008 00:00:00 GMT", "description": "The large subglacial Lake Vostok in Antarctica is unique ecological site with a novel microbial biota. The temperatures, pressures and lack of light all select for organisms that may not exist anywhere else on Earth. The accretion ice (lake water frozen to the bottom of the lower surface of the glacier) has preserved microbial samples from each region of Lake Vostok as the glacier passes over and into the lake. Thus, without contaminating the lake with microorganisms from the surface, microbes originating from the lake can be collected, transported to the laboratory and studied. Two of the deepest ice cores sections in this project are part of the international allocation. \n\nThe will be shared between four researchers (Sergey Bulat from Russia, Jean-Robert Petit and Daniel Prieur from France, Scott Rogers from USA). The United States team will study, isolate, and characterize bacteria, fungi, and viruses that have been sampled from the lake through the process of ice accretion to the lower surface of 3500+m thick glacier overriding the lake. The project will involve a suite of methods, including molecular, morphological, and cultural. This includes observation and description by fluorescence, light, and electron microscopy, isolation on thirteen separate cultural media, polymerase chain reaction amplification, DNA sequencing, and phylogenetic analyses. Eleven accretion ice core sections, as well as two glacial ice core sections. As well as two glacial ice core sections will be studied. The accretion ice core sections, as well as two glacial ice core sections will be studied. The accretion ice core sections represent all of the major regions of the lake that have been sampled by the accretion process in the vicinity of the Vostok 5G ice core. The broader impacts of the work relate to the impact the results will have on the filed. These long=isolated lakes, deep below the Antarctic ice sheet may contain novel uniquely adapted organisms. Glacial ice contains an enormous diversity of entrapped microbes, some of which may be metabolically active in the ice. The microbes from Lake Vostok are of special interest, since they are adapted to cold, dark, and high pressure. Thus, their enzyme systems and biochemical pathways may be significantly different from those in the microbes that are the subject of current studies. As such, these organisms may form compounds that may have useful applications. Also, study of the accretion ice, and eventually the water, from Lake Vostok will provide a basis for the study of other subglacial lakes. Additionally, study of the microbes in the accretion ice will be useful to those planning to study analogous systems on ice-covered planets and moons.", "east": 106.8, "geometry": ["POINT(106.8 -72.4667)"], "keywords": "Antarctica; Biota; Cryosphere; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Hydrothermal Vent; Lake Vostok; Microbes; Subglacial Lake", "locations": "Lake Vostok; Antarctica", "north": -72.4667, "nsf_funding_programs": null, "persons": "Rogers, Scott O.", "project_titles": "Comprehensive Biological Study of Vostok Accretion Ice", "projects": [{"proj_uid": "p0000566", "repository": "USAP-DC", "title": "Comprehensive Biological Study of Vostok Accretion Ice"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -72.4667, "title": "Comprehensive Biological Study of Vostok Accretion Ice", "uid": "600052", "west": 106.8}]
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Dataset Title/Abstract/Map | NSF Award(s) | Date Created | PIs / Scientists | Project Links | Abstract | Bounds Geometry | Geometry | Selected | Visible |
---|---|---|---|---|---|---|---|---|---|
Hyperspectral reflectance values and biophysicochemical properties of biocrusts and soils in the Fryxell Basin, McMurdo Dry Valleys, Antarctica
|
2044924 |
2024-04-03 | Barrett, John | No project link provided | Microbial communities are the primary drivers of carbon cycling in the McMurdo Dry Valleys of Antarctica. Dense microbial mats, consisting mainly of photosynthetic cyanobacteria, occupy aquatic areas associated with streams and lakes. Other microbial communities also occur at lower densities as patchy surface biological soil crusts (biocrusts) across the terrestrial landscape. Multispectral satellite data have been used to model microbial mat abundance in high-density areas like stream and lake margins, but no previous studies had investigated the lower detection limits of biocrusts. Here, we describe remote sensing and field-based survey and sampling approaches to study the detectability and distribution of biocrusts in the McMurdo Dry Valleys. Using a combination of multi- and hyperspectral tools and spectral linear unmixing, we modeled the abundances of biocrust in eastern Taylor Valley. Our spectral approaches can detect low masses of biocrust material in laboratory microcosms down to biocrust concentrations of 1% by mass. These techniques also distinguish the spectra of biocrust from both surface rock and mineral signatures from orbit. We found that biocrusts are present throughout the soils of eastern Taylor Valley and are associated with diverse underlying soil communities. The densest biocrust communities identified in this study had total organic carbon 5x greater than the content of typical arid soils. The most productive biocrusts were located downslope of melting snowpacks in unique soil ecosystems that are distinct from the surrounding arid landscape. There are similarities between the snowpack and stream sediment communities (high diversity of soil invertebrates) as well as their ecosystem properties (e.g., persistence of liquid water, high transfer of available nutrients, lower salinity from flushing) compared to the typical arid terrestrial ecosystem of the dry valleys. Our approach extends the capability of orbital remote sensing of photosynthetic communities out of the aquatic margins and into the drier soils which comprise most of this landscape. This interdisciplinary work is critical for measuring and monitoring terrestrial carbon stocks and predicting future ecosystem dynamics in this currently water-limited but increasingly dynamic Antarctic landscape, which is particularly climate-sensitive and difficult to access. | ["POLYGON((161.70776367188 -77.519802097166,161.899475097661 -77.519802097166,162.091186523442 -77.519802097166,162.282897949223 -77.519802097166,162.474609375004 -77.519802097166,162.666320800785 -77.519802097166,162.858032226566 -77.519802097166,163.049743652347 -77.519802097166,163.241455078128 -77.519802097166,163.433166503909 -77.519802097166,163.62487792969 -77.519802097166,163.62487792969 -77.54867059480199,163.62487792969 -77.57753909243799,163.62487792969 -77.606407590074,163.62487792969 -77.63527608771,163.62487792969 -77.664144585346,163.62487792969 -77.69301308298199,163.62487792969 -77.72188158061799,163.62487792969 -77.750750078254,163.62487792969 -77.77961857589,163.62487792969 -77.808487073526,163.433166503909 -77.808487073526,163.241455078128 -77.808487073526,163.049743652347 -77.808487073526,162.858032226566 -77.808487073526,162.666320800785 -77.808487073526,162.474609375004 -77.808487073526,162.282897949223 -77.808487073526,162.091186523442 -77.808487073526,161.899475097661 -77.808487073526,161.70776367188 -77.808487073526,161.70776367188 -77.77961857589,161.70776367188 -77.750750078254,161.70776367188 -77.72188158061799,161.70776367188 -77.69301308298199,161.70776367188 -77.664144585346,161.70776367188 -77.63527608771,161.70776367188 -77.606407590074,161.70776367188 -77.57753909243799,161.70776367188 -77.54867059480199,161.70776367188 -77.519802097166))"] | ["POINT(162.666320800785 -77.664144585346)"] | false | false |
Heterotrophic Bacterial Production Samples from Station E (Palmer Station, Antarctica) and Associated Incubation Experiments
|
1543450 |
2023-01-03 | Countway, Peter; Matrai, Patricia |
Microbial Community Structure and Expression of Functional Genes Involved in the Seasonal Cycling of DMSP in the Southern Ocean |
Rates of heterotrophic bacterial production (BP) via 3H-Leu uptake were estimated for samples collected from Station E (Palmer Station, Antarctica) and associated incubation experiments. Rates of BP in seawater incubations greatly exceeded BP rates in the environment, likely due to stimulation of phytoplankton blooms and addition of DMSP in experimental treatments. Methods for determining BP were identical to those used by Palmer LTER investigators. References for the analytical methods used for these analyses are included in a secondary tab with the uploaded data. | ["POLYGON((-66 -63,-65.7 -63,-65.4 -63,-65.1 -63,-64.8 -63,-64.5 -63,-64.2 -63,-63.9 -63,-63.6 -63,-63.3 -63,-63 -63,-63 -63.3,-63 -63.6,-63 -63.9,-63 -64.2,-63 -64.5,-63 -64.8,-63 -65.1,-63 -65.4,-63 -65.7,-63 -66,-63.3 -66,-63.6 -66,-63.9 -66,-64.2 -66,-64.5 -66,-64.8 -66,-65.1 -66,-65.4 -66,-65.7 -66,-66 -66,-66 -65.7,-66 -65.4,-66 -65.1,-66 -64.8,-66 -64.5,-66 -64.2,-66 -63.9,-66 -63.6,-66 -63.3,-66 -63))"] | ["POINT(-64.5 -64.5)"] | false | false |
Flow Cytometry Samples from Station E (Palmer Station, Antarctica) and Associated Incubation Experiments
|
1543450 |
2023-01-03 | Countway, Peter; Matrai, Patricia |
Microbial Community Structure and Expression of Functional Genes Involved in the Seasonal Cycling of DMSP in the Southern Ocean |
Flow cytometry samples were collected from Station E (Palmer Station, Antarctica) and associated incubation experiments with Station E water. Samples were analyzed for Phytoplankton (<20 um), Cryptophytes (<20 um), Heterotrophic Nanoflagellates (<20 um) and Total Bacteria. All flow cytometric analyses were performed at Bigelow Laboratory for Ocean Sciences. An overview of the analytical methods used for these samples is included in a secondary tab with the uploaded data. | ["POLYGON((-66 -63,-65.7 -63,-65.4 -63,-65.1 -63,-64.8 -63,-64.5 -63,-64.2 -63,-63.9 -63,-63.6 -63,-63.3 -63,-63 -63,-63 -63.3,-63 -63.6,-63 -63.9,-63 -64.2,-63 -64.5,-63 -64.8,-63 -65.1,-63 -65.4,-63 -65.7,-63 -66,-63.3 -66,-63.6 -66,-63.9 -66,-64.2 -66,-64.5 -66,-64.8 -66,-65.1 -66,-65.4 -66,-65.7 -66,-66 -66,-66 -65.7,-66 -65.4,-66 -65.1,-66 -64.8,-66 -64.5,-66 -64.2,-66 -63.9,-66 -63.6,-66 -63.3,-66 -63))"] | ["POINT(-64.5 -64.5)"] | false | false |
Flow cytometry enumeration of virus-like and bacteria-like abundance in Ace, Deep, & Organic lakes (Antarctica)
|
1644155 |
2022-12-12 | Twining, Benjamin; Martinez-Martinez, Joaquin |
Viral control of microbial communities in Antarctic lakes |
Varying depth samples from Ace, Deep, & Organic Lake were obtained between 2013-2014. These samples were size fractionated by filtration for metagenomic analyses. Viral and bacterial abundances were determine on the filtrate fractions by flow cytometric analysis. Glutaraldehyde-fixed samples were stained with SYBR Green I fluorescence dye and virus-like particle (VLP) and bacteria-like cell (BLC) populations were discriminated based on green fluorescence and side scatter flow cytometry signals. Several distinct VLP and BLC populations where enumerated from Ace Lake and Organic Lake samples that revealed temporal and depth differences. Discrete VLP and BLC populations could not be discerned from Deep Lake samples. These files include the original flow cytometry particle counts (raw data), the gating templates used to count VLP and BLC populations (analysis_templates), and the resulting particle counts (analyzed). | ["POLYGON((-78.1833 -68.4333,-78.16499 -68.4333,-78.14668 -68.4333,-78.12837 -68.4333,-78.11006 -68.4333,-78.09175 -68.4333,-78.07344 -68.4333,-78.05513 -68.4333,-78.03682 -68.4333,-78.01851 -68.4333,-78.0002 -68.4333,-78.0002 -68.43664,-78.0002 -68.43998,-78.0002 -68.44332,-78.0002 -68.44666000000001,-78.0002 -68.45,-78.0002 -68.45334,-78.0002 -68.45668,-78.0002 -68.46002,-78.0002 -68.46336000000001,-78.0002 -68.4667,-78.01851 -68.4667,-78.03682 -68.4667,-78.05513 -68.4667,-78.07344 -68.4667,-78.09175 -68.4667,-78.11006 -68.4667,-78.12837 -68.4667,-78.14668 -68.4667,-78.16499 -68.4667,-78.1833 -68.4667,-78.1833 -68.46336000000001,-78.1833 -68.46002,-78.1833 -68.45668,-78.1833 -68.45334,-78.1833 -68.45,-78.1833 -68.44666000000001,-78.1833 -68.44332,-78.1833 -68.43998,-78.1833 -68.43664,-78.1833 -68.4333))"] | ["POINT(-78.09175 -68.45)"] | false | false |
Royal Society Range Headland Moraine Belt Radiocarbon Data
|
0944150 |
2022-04-20 | Hall, Brenda |
Sensitivity of the Antarctic Ice Sheet to Climate Change over the Last Two Glacial/Interglacial Cycles |
This dataset contains radiocarbon dates of benthic algal (cyanobacterial) mats within moraines associated with Ross Sea drift on the headlands of the Royal Society Range and covers the time period ~12-20 ka. | ["POLYGON((163.5 -77.3,163.65 -77.3,163.8 -77.3,163.95 -77.3,164.1 -77.3,164.25 -77.3,164.4 -77.3,164.55 -77.3,164.7 -77.3,164.85 -77.3,165 -77.3,165 -77.39,165 -77.48,165 -77.57,165 -77.66,165 -77.75,165 -77.84,165 -77.93,165 -78.02,165 -78.11,165 -78.2,164.85 -78.2,164.7 -78.2,164.55 -78.2,164.4 -78.2,164.25 -78.2,164.1 -78.2,163.95 -78.2,163.8 -78.2,163.65 -78.2,163.5 -78.2,163.5 -78.11,163.5 -78.02,163.5 -77.93,163.5 -77.84,163.5 -77.75,163.5 -77.66,163.5 -77.57,163.5 -77.48,163.5 -77.39,163.5 -77.3))"] | ["POINT(164.25 -77.75)"] | false | false |
Metagenomic analysis of apparently healthy and tumor samples using Kaiju software
|
1947040 |
2022-03-14 | Desvignes, Thomas; Fontenele, Rafaela S. ; Kraberger, Simona ; Varsani, Arvind; Postlethwait, John |
EAGER: Origin and Physiological Consequences of a Neoplasm Outbreak in Antarctic Fish |
Metagenomic analyses of apparently healthy and tumor samples using Kaiju v.1.7.4 software and a custom database generated from NCBI NR database retrieved on July 24th, 2021, and containing all viruses, archaea, and bacteria sequences, as well as microbial eukaryotes and Trematomus spp. fish sequences. | ["POLYGON((-63.1 -63.9,-63.02 -63.9,-62.94 -63.9,-62.86 -63.9,-62.78 -63.9,-62.7 -63.9,-62.62 -63.9,-62.54 -63.9,-62.46 -63.9,-62.38 -63.9,-62.3 -63.9,-62.3 -64.01,-62.3 -64.12,-62.3 -64.23,-62.3 -64.34,-62.3 -64.45,-62.3 -64.56,-62.3 -64.67,-62.3 -64.78,-62.3 -64.89,-62.3 -65,-62.38 -65,-62.46 -65,-62.54 -65,-62.62 -65,-62.7 -65,-62.78 -65,-62.86 -65,-62.94 -65,-63.02 -65,-63.1 -65,-63.1 -64.89,-63.1 -64.78,-63.1 -64.67,-63.1 -64.56,-63.1 -64.45,-63.1 -64.34,-63.1 -64.23,-63.1 -64.12,-63.1 -64.01,-63.1 -63.9))"] | ["POINT(-62.7 -64.45)"] | false | false |
Metadata accompanying BioProject SUB4579142
|
1656344 |
2019-02-04 | Bowman, Jeff |
A Preliminary Assessment of the Influence of Ice Cover on Microbial Carbon and Energy Acquisition during the Antarctic Winter-spring Seasonal Transition |
This dataset contains bacterial production, primary production, chlorophyll biomass, and photosynthetic parameters for samples archived in NCBI SRA as SUB4579142. | ["POLYGON((-64.1 -64.75,-64.08 -64.75,-64.06 -64.75,-64.04 -64.75,-64.02 -64.75,-64 -64.75,-63.98 -64.75,-63.96 -64.75,-63.94 -64.75,-63.92 -64.75,-63.9 -64.75,-63.9 -64.775,-63.9 -64.8,-63.9 -64.825,-63.9 -64.85,-63.9 -64.875,-63.9 -64.9,-63.9 -64.925,-63.9 -64.95,-63.9 -64.975,-63.9 -65,-63.92 -65,-63.94 -65,-63.96 -65,-63.98 -65,-64 -65,-64.02 -65,-64.04 -65,-64.06 -65,-64.08 -65,-64.1 -65,-64.1 -64.975,-64.1 -64.95,-64.1 -64.925,-64.1 -64.9,-64.1 -64.875,-64.1 -64.85,-64.1 -64.825,-64.1 -64.8,-64.1 -64.775,-64.1 -64.75))"] | ["POINT(-64 -64.875)"] | false | false |
Seasonal Succession of Bacterial Communities in Coastal Waters of the Western Antarctic Peninsula
|
1141993 |
2017-06-12 | Rich, Jeremy |
Collaborative Research: Microbial Community Assembly in Coastal Waters of the Western Antarctic Peninsula |
From winter to late summer during the 2013-2014 season at Palmer Station, Antarctica, we collected weekly to bi-weekly samples of the seawater intake to measure changes in bacterial community composition, based on sequencing 16S rRNA genes. Along with the sequences, we collected data on environmental parameters in the samples (chlorophyll a, bacterial production, salinity, nutrients, bacterial cell numbers, and particulate organic carbon and nitrogen). | ["POINT(-64.05 -64.77)"] | ["POINT(-64.05 -64.77)"] | false | false |
Ammonia Oxidation Versus Heterotrophy in Crenarchaeota Populations from Marine Environments West of the Antarctic Peninsula
|
0838996 |
2014-01-01 | Hollibaugh, James T. |
Ammonia Oxidation Versus Heterotrophy in Crenarchaeota Populations from Marine Environments West of the Antarctic Peninsula |
Ammonia oxidation is the first step in the conversion of regenerated nitrogen to dinitrogen gas, a 3-step pathway mediated by 3 distinct guilds of bacteria and archaea. Ammonia oxidation and the overall process of nitrification-denitrification have received relatively little attention in polar oceans where the effects of climate change on biogeochemical rates are likely to be pronounced. Previous work on Ammonia Oxidizing Archaea (AOA) in the Palmer LTER study area West of the Antarctic Peninsula (WAP), has suggested strong vertical segregation of crenarchaeote metabolism, with the 'winter water' (WW, ~50-100 m depth range) dominated by non-AOA crenarchaeotes, while Crenarchaeota populations in the 'circumpolar deep water' (CDW), which lies immediately below the winter water (150-3500 m), are dominated by AOA. Analysis of a limited number of samples from the Arctic Ocean did not reveal a comparable vertical segregation of AOA, and suggested that AOA and Crenarchaeota abundance is much lower there than in the Antarctic. These findings led to 3 hypotheses that will be tested in this project: 1) the apparent low abundance of Crenarchaeota and AOA in Arctic Ocean samples may be due to spatial or temporal variability in populations; 2) the WW population of Crenarchaeota in the WAP is dominated by a heterotroph; 3) the WW population of Crenarchaeota in the WAP 'grows in' during spring and summer after this water mass forms. The study will contribute substantially to understanding an important aspect of the nitrogen cycle in the Palmer LTER (Long Term Ecological Research) study area by providing insights into the ecology and physiology of AOA. The natural segregation of crenarchaeote phenotypes in waters of the WAP, coupled with metagenomic studies in progress in the same area by others (A. Murray, H. Ducklow), offers the possibility of major breakthroughs in understanding of the metabolic capabilities of these organisms. This knowledge is needed to model how water column nitrification will respond to changes in polar ecosystems accompanying global climate change. The Principal Investigator will participate fully in the education and outreach efforts of the Palmer LTER, including making highlights of our findings available for posting to their project web site and participating in outreach (for example, Schoolyard LTER). The research also will involve undergraduates (including the field work if possible) and will support high school interns in the P.I.'s laboratory over the summer. | ["POLYGON((-79 -63,-77.5 -63,-76 -63,-74.5 -63,-73 -63,-71.5 -63,-70 -63,-68.5 -63,-67 -63,-65.5 -63,-64 -63,-64 -63.8,-64 -64.6,-64 -65.4,-64 -66.2,-64 -67,-64 -67.8,-64 -68.6,-64 -69.4,-64 -70.2,-64 -71,-65.5 -71,-67 -71,-68.5 -71,-70 -71,-71.5 -71,-73 -71,-74.5 -71,-76 -71,-77.5 -71,-79 -71,-79 -70.2,-79 -69.4,-79 -68.6,-79 -67.8,-79 -67,-79 -66.2,-79 -65.4,-79 -64.6,-79 -63.8,-79 -63))"] | ["POINT(-71.5 -67)"] | false | false |
Metabolic Activities and Gene Expression of Marine Psychrophiles in Cold Ice
|
0739783 |
2013-01-01 | Junge, Karen |
Metabolic Activities and Gene Expression of Marine Psychrophiles in Cold Ice |
The mechanisms enabling bacteria to be metabolically active at very low temperatures are of considerable importance to polar microbial ecology, astrobiology, climate and cryopreservation. This research program has two main objectives. The first is to investigate metabolic activities and gene expression of polar marine psychrophilic bacteria when confronted with freezing conditions at temperatures above the eutectic of seawater (<54C) to unveil cold adaptation mechanisms with relevance to wintertime sea-ice ecology. The second objective is to discern if psychrophilic processes of leucine incorporation into proteins, shown to occur to -196C, amount to metabolic activity providing for the survival of cells or are merely biochemical reactions still possible in flash-frozen samples without any effect on survival. We will examine extracellular and intracellular processes of psychrophilic activity above and below the eutectic by (i) determining the temperature range of metabolic activities such as DNA synthesis, carbon utilization, respiration and ATP generation using radioactive tracer technology, including a control at liquid helium temperature (-268.9C), (ii) analyzing gene expression in ice using whole genome and microarray analyses and iii) examining the role of exopolymeric substances (EPS) and ice micro-physics for the observed activity using an in-situ microscopy technique. Results of the proposed research can be expected to aid in the determination of cellular and genetic strategies that allow cells to maintain activity at extremely low temperatures within an icy matrix and/or to resume activity again when more growth-permissive conditions are encountered. The research is an interdisciplinary collaboration involving three different institutions with participants in Oceanography, Genomics, and Geophysical Sciences. The proposed activity will support the beginning professional career of a female researcher and will serve as the basis for several undergraduate student laboratory projects. | ["POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))"] | ["POINT(0 -89.999)"] | false | false |
Geochemistry and Microbiology of the Extreme Aquatic Environment in Lake Vida, East Antarctica
|
0739681 0739698 |
2013-01-01 | Murray, Alison |
Collaborative Research: Geochemistry and Microbiology of the Extreme Aquatic Environment in Lake Vida, East Antarctica |
Lake Vida is the largest lake of the McMurdo Dry Valleys, with an approximately 20 m ice cover overlaying a brine of unknown depth with at least 7 times seawater salinity and temperatures below -10 degrees C year-round. Samples of brine collected from ice above the main water body contain 1) the highest nitrous oxide levels of any natural water body on Earth, 2) unusual geochemistry including anomalously high ammonia and iron concentrations, 3) high microbial counts with an unusual proportion (99%) of ultramicrobacteria. The microbial community is unique even compared to other Dry Valley Lakes. The research proposes to enter, for the first time the main brine body below the thick ice of Lake Vida and perform in situ measurements, collect samples of the brine column, and collect sediment cores from the lake bottom for detailed geochemical and microbiological analyses. The results will allow the characterization of present and past life in the lake, assessment of modern and past sedimentary processes, and determination of the lake's history. The research will be conducted by a multidisciplinary team that will uncover the biogeochemical processes associated with a non-photosynthetic microbial community isolated for a significant period of time. This research will address diversity, adaptive mechanisms and evolutionary processes in the context of the physical evolution of the environment of Lake Vida. Results will be widely disseminated through publications, presentations at national and international meetings, through the Subglacial Antarctic Lake Exploration (SALE) web site and the McMurdo LTER web site. The research will support three graduate students and three undergraduate research assistants. The results will be incorporated into a new undergraduate biogeosciences course at the University of Illinois at Chicago which has an extremely diverse student body, dominated by minorities. | ["POINT(161.931 -77.3885)"] | ["POINT(161.931 -77.3885)"] | false | false |
Biogeochemistry of Cyanobactrial Mats and Hyporheic Zone Microbes in McMurdo Dry Valley Glacial Meltwater Streams
|
0739648 |
2013-01-01 | Cary, S. Craig |
Collaborative Research: Biogeochemistry of Cyanobactrial Mats and Hyporheic Zone Microbes in McMurdo Dry Valley Glacial Meltwater Streams |
The glacial streams of the McMurdo Dry Valleys have extensive cyanobacterial mats that are a probable source of fixed C and N to the Valleys. The research will examine the interplay between the microbial mats in the ephemeral glacial streams and the microbiota of the hyporheic soils (wetted soil zone) underlying and adjacent to those mats. It is hypothesized that the mats are important sources of organic carbon and fixed nitrogen for the soil communities of the hyporheic zone, and release dissolved organic carbon (DOC) and nitrogen (DON) that serves the entire Dry Valley ecosystem. Field efforts will entail both observational and experimental components. Direct comparisons will be made between the mats and microbial populations underlying naturally rehydrated and desiccated mat areas, and between mat areas in the melt streams of the Adams and Miers Glaciers in Miers Valley. Both physiological and phylogenetic indices of the soil microbiota will be examined. Observations will include estimates of rates of mat carbon and nitrogen fixation, soil respiration and leucine and thymidine uptake (as measures of protein & DNA synthesis, respectively) by soil bacteria, bacterial densities and their molecular ecology. Experimental manipulations will include experimental re-wetting of soils and observations of the time course of response of the microbial community. The research will integrate modern molecular genetic approaches (ARISA-DNA fingerprinting and ultra deep 16S rDNA microbial phylogenetic analysis) with geochemistry to study the diversity, ecology, and function of microbial communities that thrive in these extreme environments. The broader impacts of the project include research and educational opportunities for graduate students and a postdoctoral associate. The P.I.s will involve undergraduates as work-study students and in REU programs, and will participate in educational and outreach programs. | ["POINT(163 -77.5)"] | ["POINT(163 -77.5)"] | false | false |
Ice Nucleation by Marine Psychrophiles
|
0801392 |
2010-01-01 | Swanson, Brian |
Ice Nucleation by Marine Psychrophiles |
The primary objective of this research is to investigate polar marine psychrophilic bacteria for their potential to nucleate ice using a combination of microbiological, molecular biological and atmospheric science approaches in the laboratory. Very little is known about how psychrophiles interact and cope with ice or their adaptations to conditions of extreme cold and salinity. This work will involve a series of laboratory experiments using a novel freeze-tube technique for assaying freezing spectra which will provide quantitative information on: (i) the temperature-dependent freezing rates for heterogeneously frozen droplets containing sea-ice bacteria, (ii) the proportional occurrence of ice-nucleation activity versus anti-freeze activity among sea-ice bacterial isolates and (iii) the temperature-dependent freezing rates of bacteria with ice-nucleation activity grown at a range of temperatures and salinities. The compound(s) responsible for the observed activity will be identified, which is an essential step towards the development of an in-situ bacterial ice-nucleation detection assay that can be applied in the field to Antarctic water and cloud samples. One of the goals of this work is to better understand survival and cold adaptation processes of polar marine bacteria confronted with freezing conditions in sea ice. Since sea ice strongly impacts polar, as well as the global climates, this research is of significant interest because it will also provide data for accessing the importance of bacterial ice nucleation in the formation of sea ice. These measurements of ice-nucleation rates will be the first high-resolution measurements for psychrophilic marine bacteria. Another goal is to better understand the impact of bacterial ice initiation processes in polar clouds by making high-resolution measurements of nucleation rates for cloud bacteria found over Arctic and Antarctic regions. Initial measurements indicate these bacteria nucleate ice at warmer temperatures and the effect in polar regions may be quite important, since ice can strongly impact cloud dynamics, cloud radiative properties, precipitation formation, and cloud chemistry. If these initial measurements are confirmed, the data collected here will be important for improving the understanding of polar cloud processes and models. A third goal is to better understand the molecular basis of marine bacterial ice nucleation by characterizing the ice-nucleation compound and comparing it with those of known plant-derived ice-nucleating bacteria, which are the only ice-nucleating bacteria examined in detail to date. The proposed activity will support the beginning academic career of a post-doctoral researcher and will serve as the basis for several undergraduate student laboratory projects. Results from this research will be widely published in various scientific journals and outreach venues. | ["POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))"] | ["POINT(0 -89.999)"] | false | false |
What Limits Denitrification and Bacterial Growth in Lake Bonney, Taylor Valley, Antarctica?
|
0230276 |
2009-01-01 | Ward, Bess |
Collaborative Research: What Limits Denitrification and Bacterial Growth in Lake Bonney, Taylor Valley, Antarctica? |
Denitrification is the main process by which fixed nitrogen is lost from ecosystems and the regulation of this process may directly affect primary production and carbon cycling over short and long time scales. Previous investigations of the role of bioactive metals in regulating denitrification in bacteria from permanently ice-covered Lake Bonney in the Taylor Valley of East Antarctica indicated that denitrifying bacteria can be negatively affected by metals such as copper, iron, cadmium, lead, chromium, nickel, silver and zinc; and that there is a distinct difference in denitrifying activity between the east and west lobes of the lake. Low iron concentrations were found to exacerbate the potential toxicity of the other metals, while silver has the potential to specifically inhibit denitrification because of its ability to interfere with copper binding in redox proteins, such as nitrite reductase and nitrous oxide reductase. High silver concentrations might prevent the functioning of nitrous oxide reductase in the same way that simple copper limitation does, thereby causing the buildup of nitrous oxide and resulting in a nonfunctional nitrogen cycle. Other factors, such as oxygen concentration, are likely also to affect bacterial activity in Lake Bonney. This project will investigate silver toxicity, general metal toxicity and oxygen concentration to determine their effect on denitrification in the lake by using a suite of 'sentinel' strains of denitrifying bacteria (isolated from the lake) incubated in Lake Bonney water and subjected to various treatments. The physiological responses of these strains to changes in metal and oxygen concentration will be quantified by flow cytometric detection of single cell molecular probes whose sensitivity and interpretation have been optimized for the sentinel strains. Understanding the relationships between metals and denitrification is expected to enhance our understanding of not only Lake Bonney's unusual nitrogen cycle, but more generally, of the potential role of metals in the regulation of microbial nitrogen transformations. The broader impacts of this work include not only a better understanding of regional biogeochemistry and global perspectives on these processes; but also the training of graduate students and a substantial outreach effort for school children. | ["POLYGON((162 -77.2,162.16 -77.2,162.32 -77.2,162.48 -77.2,162.64 -77.2,162.8 -77.2,162.96 -77.2,163.12 -77.2,163.28 -77.2,163.44 -77.2,163.6 -77.2,163.6 -77.26,163.6 -77.32,163.6 -77.38,163.6 -77.44,163.6 -77.5,163.6 -77.56,163.6 -77.62,163.6 -77.68,163.6 -77.74,163.6 -77.8,163.44 -77.8,163.28 -77.8,163.12 -77.8,162.96 -77.8,162.8 -77.8,162.64 -77.8,162.48 -77.8,162.32 -77.8,162.16 -77.8,162 -77.8,162 -77.74,162 -77.68,162 -77.62,162 -77.56,162 -77.5,162 -77.44,162 -77.38,162 -77.32,162 -77.26,162 -77.2))"] | ["POINT(162.8 -77.5)"] | false | false |
Interactive Effects of UV Radiation and Vertical Mixing on Phytoplankton and Bacterial Productivity of Ross Sea Phaeocystis Blooms
|
0127022 |
2008-01-01 | Jeffrey, Wade H. |
Collaborative Proposal: Interactive Effects of UV Radiation and Vertical Mixing on Phytoplankton and Bacterial Productivity of Ross See Phaeocystis Blooms |
Data from five research cruises from OPP grant entitled "Interactive Effects of UV and Vertical Mixing on Phytoplankton and Bacterial Productivity of Ross Sea Phaeocystis Bloom (OPP0127022). The first two cruises were ships of opportunity cruises in the Pacific Ocean, the first collecting data between Valapariso, Chile and San Diego, CA (October 2002). The second and third cruises combined to provide data in a transect from 70 N to 68 S latitude in the Pacific ocean (August - November 2003). The remaining two cruises were to the Ross Sea, the first in December 2004 - January 2005 and the last from October - November 2005. Data presented include microbial biomass (bacterial direct counts) and chlorophyll a concentrations, bacterial production (as leucine or thymidine incorporation), solar irradiance data, CTD profiles, and one set of under water diffuse attenuation coefficients of for the Ross Sea. | ["POLYGON((159.8 -43.3,161.8 -43.3,163.8 -43.3,165.8 -43.3,167.8 -43.3,169.8 -43.3,171.8 -43.3,173.8 -43.3,175.8 -43.3,177.8 -43.3,179.8 -43.3,179.8 -45.65,179.8 -48,179.8 -50.35,179.8 -52.7,179.8 -55.05,179.8 -57.4,179.8 -59.75,179.8 -62.1,179.8 -64.45,179.8 -66.8,177.8 -66.8,175.8 -66.8,173.8 -66.8,171.8 -66.8,169.8 -66.8,167.8 -66.8,165.8 -66.8,163.8 -66.8,161.8 -66.8,159.8 -66.8,159.8 -64.45,159.8 -62.1,159.8 -59.75,159.8 -57.4,159.8 -55.05,159.8 -52.7,159.8 -50.35,159.8 -48,159.8 -45.65,159.8 -43.3))", "POLYGON((167 -74.4,168.36 -74.4,169.72 -74.4,171.08 -74.4,172.44 -74.4,173.8 -74.4,175.16 -74.4,176.52 -74.4,177.88 -74.4,179.24 -74.4,180.6 -74.4,180.6 -74.735,180.6 -75.07,180.6 -75.405,180.6 -75.74,180.6 -76.075,180.6 -76.41,180.6 -76.745,180.6 -77.08,180.6 -77.415,180.6 -77.75,179.24 -77.75,177.88 -77.75,176.52 -77.75,175.16 -77.75,173.8 -77.75,172.44 -77.75,171.08 -77.75,169.72 -77.75,168.36 -77.75,167 -77.75,167 -77.415,167 -77.08,167 -76.745,167 -76.41,167 -76.075,167 -75.74,167 -75.405,167 -75.07,167 -74.735,167 -74.4))"] | ["POINT(169.8 -55.05)", "POINT(173.8 -76.075)"] | false | false |
Comprehensive Biological Study of Vostok Accretion Ice
|
0536870 |
2008-01-01 | Rogers, Scott O. |
Comprehensive Biological Study of Vostok Accretion Ice |
The large subglacial Lake Vostok in Antarctica is unique ecological site with a novel microbial biota. The temperatures, pressures and lack of light all select for organisms that may not exist anywhere else on Earth. The accretion ice (lake water frozen to the bottom of the lower surface of the glacier) has preserved microbial samples from each region of Lake Vostok as the glacier passes over and into the lake. Thus, without contaminating the lake with microorganisms from the surface, microbes originating from the lake can be collected, transported to the laboratory and studied. Two of the deepest ice cores sections in this project are part of the international allocation. The will be shared between four researchers (Sergey Bulat from Russia, Jean-Robert Petit and Daniel Prieur from France, Scott Rogers from USA). The United States team will study, isolate, and characterize bacteria, fungi, and viruses that have been sampled from the lake through the process of ice accretion to the lower surface of 3500+m thick glacier overriding the lake. The project will involve a suite of methods, including molecular, morphological, and cultural. This includes observation and description by fluorescence, light, and electron microscopy, isolation on thirteen separate cultural media, polymerase chain reaction amplification, DNA sequencing, and phylogenetic analyses. Eleven accretion ice core sections, as well as two glacial ice core sections. As well as two glacial ice core sections will be studied. The accretion ice core sections, as well as two glacial ice core sections will be studied. The accretion ice core sections represent all of the major regions of the lake that have been sampled by the accretion process in the vicinity of the Vostok 5G ice core. The broader impacts of the work relate to the impact the results will have on the filed. These long=isolated lakes, deep below the Antarctic ice sheet may contain novel uniquely adapted organisms. Glacial ice contains an enormous diversity of entrapped microbes, some of which may be metabolically active in the ice. The microbes from Lake Vostok are of special interest, since they are adapted to cold, dark, and high pressure. Thus, their enzyme systems and biochemical pathways may be significantly different from those in the microbes that are the subject of current studies. As such, these organisms may form compounds that may have useful applications. Also, study of the accretion ice, and eventually the water, from Lake Vostok will provide a basis for the study of other subglacial lakes. Additionally, study of the microbes in the accretion ice will be useful to those planning to study analogous systems on ice-covered planets and moons. | ["POINT(106.8 -72.4667)"] | ["POINT(106.8 -72.4667)"] | false | false |