{"dp_type": "Dataset", "free_text": "Microbiology"}
[{"awards": "1141978 Foreman, Christine", "bounds_geometry": ["POLYGON((161.1667 -77.117,161.21673 -77.117,161.26676 -77.117,161.31679 -77.117,161.36682 -77.117,161.41685 -77.117,161.46688 -77.117,161.51691 -77.117,161.56694 -77.117,161.61697 -77.117,161.667 -77.117,161.667 -77.117,161.667 -77.117,161.667 -77.117,161.667 -77.117,161.667 -77.117,161.667 -77.117,161.667 -77.117,161.667 -77.117,161.667 -77.117,161.667 -77.117,161.61697 -77.117,161.56694 -77.117,161.51691 -77.117,161.46688 -77.117,161.41685 -77.117,161.36682 -77.117,161.31679 -77.117,161.26676 -77.117,161.21673 -77.117,161.1667 -77.117,161.1667 -77.117,161.1667 -77.117,161.1667 -77.117,161.1667 -77.117,161.1667 -77.117,161.1667 -77.117,161.1667 -77.117,161.1667 -77.117,161.1667 -77.117,161.1667 -77.117))"], "date_created": "Fri, 23 Mar 2018 00:00:00 GMT", "description": "Mass spectra of external metabolites were obtained with a 1290 Ultra Performance Liquid Chromatography system coupled to a 6538 Ultra High Definition Accurate-Mass Quadrupole-Time of Flight mass spectrometer operated in positive mode with an electrospray ionization source (Agilent Technologies). 30 mL of filtered media was concentrated per sample by solid phase extraction. External metabolites were re-suspended in 50% (v/v) acetonitrile, and were separated using a reverse-phase Kinetix 1.7 um C18, 100A, 150 mm - 2.1 mm column. Data presented are from UPLC-Q-TOF measurements of mass to charge ratio, retention time, and replicate-averaged extracted ion chromatogram abundance values (counts) of molecular species that demonstrated a significant change in abundance (Two-way ANOVA, adjusted P\u003c0.01) during incubations based on time point (T0: d0, T1: d27, T2: d63, T3: d98) and carbon source (Cotton Glacier: CG, Pony Lake: PL, Suwannee River: SR).", "east": 161.667, "geometry": ["POINT(161.41685 -77.117)"], "keywords": "Antarctica; Biota; Exometabolites; Mass Spectrometry; Microbes; Microbiology", "locations": "Antarctica", "north": -77.117, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "persons": "Foreman, Christine; Tigges, Michelle; Bothner, Brian", "project_titles": "Multidimensional \"omics\" characterization of microbial metabolism and dissolved organic matter in Antarctica", "projects": [{"proj_uid": "p0000408", "repository": "USAP-DC", "title": "Multidimensional \"omics\" characterization of microbial metabolism and dissolved organic matter in Antarctica"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -77.117, "title": "UPLC-Q-TOF data of Cotton Glacier exometabolites", "uid": "601089", "west": 161.1667}, {"awards": "0732917 McCormick, Michael", "bounds_geometry": ["POLYGON((299.4 -63.1,299.92 -63.1,300.44 -63.1,300.96 -63.1,301.48 -63.1,302 -63.1,302.52 -63.1,303.04 -63.1,303.56 -63.1,304.08 -63.1,304.6 -63.1,304.6 -63.29,304.6 -63.48,304.6 -63.67,304.6 -63.86,304.6 -64.05,304.6 -64.24,304.6 -64.43,304.6 -64.62,304.6 -64.81,304.6 -65,304.08 -65,303.56 -65,303.04 -65,302.52 -65,302 -65,301.48 -65,300.96 -65,300.44 -65,299.92 -65,299.4 -65,299.4 -64.81,299.4 -64.62,299.4 -64.43,299.4 -64.24,299.4 -64.05,299.4 -63.86,299.4 -63.67,299.4 -63.48,299.4 -63.29,299.4 -63.1))"], "date_created": "Sun, 17 Dec 2017 00:00:00 GMT", "description": "Ice-shelf loss along the east coast of the Antarctic Peninsula over recent decades has brought new sources of carbon and energy to the marine benthos likely affecting sediment geochemistry and microbial community composition. To better understand the long-term effects of ice-shelf loss on benthic microbial communities, we conducted a five-station survey along a 160 km transect following the historic path of retreat of the Larsen A ice shelf. All microbial community sequence data is publicly available through the Metagenomics Analysis Server at Argonne National Laboratory (MG-RAST). The project title is \"Impact of ice-shelf loss on geochemical profiles and microbial community composition in marine sediments of the Larsen A embayment, Antarctic Peninsula\". A key word search using terms from this title at the MG-RAST portal (http://metagenomics.anl.gov/) will return the complete sample list. This submitted dataset summarizes the measured environmental parameters for these same samples (lat., long., water depth, sediment depth, pH, alkalinity, dissolved oxygen, silicate, phosphate, nitrate, nitrite, and ammonium).", "east": 304.6, "geometry": ["POINT(-58 -64.05)"], "keywords": "Antarctica; Antarctic Peninsula; Chemistry:ice; Chemistry:Ice; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; LARISSA; Microbiology", "locations": "Antarctic Peninsula; Antarctica", "north": -63.1, "nsf_funding_programs": "Antarctic Integrated System Science", "persons": "McCormick, Michael", "project_titles": "Collaborative Research in IPY: Abrupt Environmental Change in the Larsen Ice Shelf System, a Multidisciplinary Approach - Marine Ecosystems.", "projects": [{"proj_uid": "p0010135", "repository": "USAP-DC", "title": "Collaborative Research in IPY: Abrupt Environmental Change in the Larsen Ice Shelf System, a Multidisciplinary Approach - Marine Ecosystems."}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -65.0, "title": "LARISSA: Impact of ice-shelf loss on geochemical profiles and microbial community composition in marine sediments of the Larsen A embayment, Antarctic Peninsula", "uid": "601073", "west": 299.4}, {"awards": "0839075 Priscu, John", "bounds_geometry": ["POINT(-112 -79)"], "date_created": "Tue, 12 Dec 2017 00:00:00 GMT", "description": "This data set includes raw concentration of prokaryotic cells for the WAIS Divide deep core, WDC06A, from 1,764 m to 2,709 m. Data were collected by a method that combines acquisition of discrete samples using a continuous ice-core melting system (McConnell et al., 2002) coupled with flow cytometry of DNA-stained samples. The method is described in detail in Santibanez et al., 2016. \r\r\nWe present the first long-term, highly resolved prokaryotic cell concentration record obtained from a polar ice core. This record, obtained from the West Antarctic Ice Sheet (WAIS) Divide (WD) ice core, spanned from the Last Glacial Maximum (LGM) to the early Holocene (EH) and showed distinct fluctuations in prokaryotic cell concentration coincident with major climatic states. This record provided strong evidence that airborne prokaryotic cell deposition differed during the LGM, LDG and EH, and that these changes in cell densities could be explained by different environmental conditions during each of these climatic periods. Our observations provide the first ice core time-series evidence for a prokaryotic response to long-term climatic and environmental processes.", "east": -112.0, "geometry": ["POINT(-112 -79)"], "keywords": "Antarctica; Biota; Cell Counts; Glaciology; Microbiology; WAIS Divide; WAIS Divide Ice Core", "locations": "WAIS Divide; Antarctica", "north": -79.0, "nsf_funding_programs": "Antarctic Glaciology", "persons": "Santibanez, Pamela; Priscu, John", "project_titles": "Collaborative Research: Integrated High Resolution Chemical and Biological Measurements on the Deep WAIS Divide Core", "projects": [{"proj_uid": "p0000273", "repository": "USAP-DC", "title": "Collaborative Research: Integrated High Resolution Chemical and Biological Measurements on the Deep WAIS Divide Core"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "WAIS Divide Ice Core", "south": -79.0, "title": "Prokaryotic cell concentration record from the WAIS Divide ice core", "uid": "601072", "west": -112.0}, {"awards": "0838970 Foreman, Christine", "bounds_geometry": ["POINT(161.667 -77.117)"], "date_created": "Wed, 01 Jan 2014 00:00:00 GMT", "description": "Dissolved organic matter (DOM) comprises a significant pool of Earth\u0027s organic carbon that dwarfs the amount present in living aquatic organisms. The properties and reactivity of DOM are not well defined, and the evolution of autochthonous DOM from its precursor materials in freshwater has not been observed. Recent sampling of a supraglacial stream formed on the Cotton Glacier in the Transantarctic Mountains revealed DOM that more closely resembles an assemblage of recognizable precursor organic compounds, based upon its UV-VIS and fluorescence spectra. It is suggested that the DOM from this water evolved over time to resemble materials present in marine and many inland surface waters. The transient nature of the system i.e., it reforms seasonally, also prevents any accumulation of the refractory DOM present in most surface waters. Thus, the Cotton Glacier provides us with a unique environment to study the formation of DOM from precursor materials. An interdisciplinary team will study the biogeochemistry of this progenitor DOM and how microbes modify it. By focusing on the chemical composition of the DOM as it shifts from precursor material to the more humified fractions, the investigators will relate this transition to bioavailability, enzymatic activity, community composition and microbial growth efficiency. This project will support education at all levels, K-12, high school, undergraduate, graduate and post-doc and will increase participation by under-represented groups in science. Towards these goals, the investigators have established relationships with girls\u0027 schools and Native American programs. Additional outreach will be carried out in coordination with PolarTREC, PolarPalooza, and if possible, an Antarctic Artist and Writer.\n", "east": 161.667, "geometry": ["POINT(161.667 -77.117)"], "keywords": "Antarctica; Biota; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Microbiology", "locations": "Antarctica", "north": -77.117, "nsf_funding_programs": null, "persons": "Foreman, Christine", "project_titles": "Collaborative Research: The Biogeochemical Evolution of Dissolved Organic Matter in a Fluvial System on the Cotton Glacier, Antarctica", "projects": [{"proj_uid": "p0000458", "repository": "USAP-DC", "title": "Collaborative Research: The Biogeochemical Evolution of Dissolved Organic Matter in a Fluvial System on the Cotton Glacier, Antarctica"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -77.117, "title": "The Biogeochemical Evolution of Dissolved Organic Matter in a Fluvial System on the Cotton Glacier, Antarctica", "uid": "600104", "west": 161.667}, {"awards": "0838955 Gast, Rebecca", "bounds_geometry": ["POLYGON((71.504166 -76.159164,71.5142214 -76.159164,71.5242768 -76.159164,71.5343322 -76.159164,71.5443876 -76.159164,71.554443 -76.159164,71.5644984 -76.159164,71.5745538 -76.159164,71.5846092 -76.159164,71.5946646 -76.159164,71.60472 -76.159164,71.60472 -76.2018032,71.60472 -76.2444424,71.60472 -76.2870816,71.60472 -76.3297208,71.60472 -76.37236,71.60472 -76.4149992,71.60472 -76.4576384,71.60472 -76.5002776,71.60472 -76.5429168,71.60472 -76.585556,71.5946646 -76.585556,71.5846092 -76.585556,71.5745538 -76.585556,71.5644984 -76.585556,71.554443 -76.585556,71.5443876 -76.585556,71.5343322 -76.585556,71.5242768 -76.585556,71.5142214 -76.585556,71.504166 -76.585556,71.504166 -76.5429168,71.504166 -76.5002776,71.504166 -76.4576384,71.504166 -76.4149992,71.504166 -76.37236,71.504166 -76.3297208,71.504166 -76.2870816,71.504166 -76.2444424,71.504166 -76.2018032,71.504166 -76.159164))"], "date_created": "Tue, 01 Jan 2013 00:00:00 GMT", "description": "This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5).\n\nMost organisms meet their carbon and energy needs using photosynthesis (phototrophy) or ingestion/assimilation of organic substances (heterotrophy). However, a nutritional strategy that combines phototrophy and heterotrophy - mixotrophy - is geographically and taxonomically widespread in aquatic systems. While the presence of mixotrophs in the Southern Ocean is known only recently, preliminary evidence indicates a significant role in Southern Ocean food webs. Recent work on Southern Ocean dinoflagellate, Kleptodinium, suggests that it sequesters functional chloroplasts of the bloom-forming haptophyte, Phaeocystis antarctica. This dinoflagellate is abundant in the Ross Sea, has been reported elsewhere in the Southern Ocean, and may have a circumpolar distribution. By combining nutritional modes. mixotrophy may offer competitive advantages over pure autotrophs and heterotrophs.\n\nThe goals of this project are to understand the importance of alternative nutritional strategies for Antarctic species that combine phototrophic and phagotrophic processes in the same organism. The research will combine field investigations of plankton and ice communities in the Southern Ocean with laboratory experiments on Kleptodinium and recently identified mixotrophs from our Antarctic culture collections. The research will address: 1) the relative contributions of phototrophy and phagotrophy in Antarctic mixotrophs; 2) the nature of the relationship between Kleptodinium and its kleptoplastids; 3) the distributions and abundances of mixotrophs and Kleptodinium in the Southern Ocean during austral spring/summer; and 4) the impacts of mixotrophs and Kleptodinium on prey populations, the factors influencing these behaviors and the physiological conditions of these groups in their natural environment. \n\nThe project will contribute to the maintenance of a culture collection of heterotrophic, phototrophic and mixotrophic Antarctic protists that are available to the scientific community, and it will train graduate and undergraduate students at Temple University. Research findings and activities will be summarized for non-scientific audiences through the PIs\u0027 websites and through other public forums, and will involve middle school teachers via collaboration with COSEE-New England.\n", "east": 71.60472, "geometry": ["POINT(71.554443 -76.37236)"], "keywords": "Biota; Microbiology; NBP0305; NBP0405; NBP0508; NBP1101; Oceans; Southern Ocean", "locations": "Southern Ocean", "north": -76.159164, "nsf_funding_programs": null, "persons": "Gast, Rebecca", "project_titles": "Collaborative Research: Alternative Nutritional Strategies in Antarctic Protists", "projects": [{"proj_uid": "p0000490", "repository": "USAP-DC", "title": "Collaborative Research: Alternative Nutritional Strategies in Antarctic Protists"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -76.585556, "title": "Alternative Nutritional Strategies in Antarctic Protists", "uid": "600103", "west": 71.504166}, {"awards": "0838850 Gooseff, Michael", "bounds_geometry": ["POLYGON((-163.3 -77.62,-163.202 -77.62,-163.104 -77.62,-163.006 -77.62,-162.908 -77.62,-162.81 -77.62,-162.712 -77.62,-162.614 -77.62,-162.516 -77.62,-162.418 -77.62,-162.32 -77.62,-162.32 -77.631,-162.32 -77.642,-162.32 -77.653,-162.32 -77.664,-162.32 -77.675,-162.32 -77.686,-162.32 -77.697,-162.32 -77.708,-162.32 -77.719,-162.32 -77.73,-162.418 -77.73,-162.516 -77.73,-162.614 -77.73,-162.712 -77.73,-162.81 -77.73,-162.908 -77.73,-163.006 -77.73,-163.104 -77.73,-163.202 -77.73,-163.3 -77.73,-163.3 -77.719,-163.3 -77.708,-163.3 -77.697,-163.3 -77.686,-163.3 -77.675,-163.3 -77.664,-163.3 -77.653,-163.3 -77.642,-163.3 -77.631,-163.3 -77.62))"], "date_created": "Tue, 01 Jan 2013 00:00:00 GMT", "description": "Two models have been proposed to describe controls over microbial biogeography. One model proposes that microbes are ubiquitously distributed across the global environment, and that environmental conditions select for taxa physiologically adapted to local physical conditions. An alternative model predicts that dispersal is the important limitation to the distribution of microorganisms and that spatial heterogeneity of microbial communities is a result of both dispersal and local environmental limitations. According to both models, spatial heterogeneity of microbial communities may be especially pronounced in extreme ecosystems where the environmental selection for organisms with suitable physiology is most strongly manifest. We propose that Antarctic terrestrial environments are ideal places to examine microbial biogeography for 3 reasons: 1) the pristine nature and remoteness of Antarctica minimizes the prevalence of exotic species dispersed through human vectors; 2) the extreme conditions of Antarctic environments provide a strong environmental filter which limits the establishment of non-indigenous taxa; and 3) extreme heterogeneity in the terrestrial environment provides natural gradients of soil conditions (temperature, water and nutrient availability). In the proposed research we will investigate the influence of snow on the composition and spatial distribution of soil microbial communities and linked biogeochemical cycling in the McMurdo Dry Valleys. We will conduct fieldwork at the landscape scale (repeated remote sensing to characterize snow distribution), at the valley and patch scales (quantify snow patch ablation, microbial communities and biogeochemical cycling in subnivian soils). We hypothesize that snow patches play an important role in structuring the spatial distribution of soil microbial communities and their associated ecosystem functioning because of the physical and hydrological influences that snow patches have on the soil environment. The research will contribute to greater public awareness of the importance of polar research to fundamental questions of biology, ecology and hydrology through direct linkages with International Antarctic Institute public outreach activities, including dissemination of web-based learning units on environmental science and microbiology, targeted as resources for secondary and post-secondary educators. Three graduate students, one postdoctoral scholar and multiple undergraduates will participate in the research activities.\n", "east": -162.32, "geometry": ["POINT(-162.81 -77.675)"], "keywords": "Antarctica; Critical Zone; Mps-1 Water Potential Sensor; Physical Properties; Soil Moisture; Soil Temperature", "locations": "Antarctica", "north": -77.62, "nsf_funding_programs": null, "persons": "Gooseff, Michael N.", "project_titles": "Collaborative Research: The Role of Snow Patches on the Spatial Distribution of Soil Microbial Communities and Biogeochemical Cycling in the Antarctic Dry Valleys", "projects": [{"proj_uid": "p0000489", "repository": "USAP-DC", "title": "Collaborative Research: The Role of Snow Patches on the Spatial Distribution of Soil Microbial Communities and Biogeochemical Cycling in the Antarctic Dry Valleys"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -77.73, "title": "The Role of Snow Patches on the Spatial Distribution of Soil Microbial Communities and Biogeochemical Cycling in the Antarctic Dry Valleys", "uid": "600100", "west": -163.3}, {"awards": "0838830 Cottrell, Matthew", "bounds_geometry": ["POLYGON((-64.079666 -64.77966,-64.0757659 -64.77966,-64.0718658 -64.77966,-64.0679657 -64.77966,-64.0640656 -64.77966,-64.0601655 -64.77966,-64.0562654 -64.77966,-64.0523653 -64.77966,-64.0484652 -64.77966,-64.0445651 -64.77966,-64.040665 -64.77966,-64.040665 -64.783261,-64.040665 -64.786862,-64.040665 -64.790463,-64.040665 -64.794064,-64.040665 -64.797665,-64.040665 -64.801266,-64.040665 -64.804867,-64.040665 -64.808468,-64.040665 -64.812069,-64.040665 -64.81567,-64.0445651 -64.81567,-64.0484652 -64.81567,-64.0523653 -64.81567,-64.0562654 -64.81567,-64.0601655 -64.81567,-64.0640656 -64.81567,-64.0679657 -64.81567,-64.0718658 -64.81567,-64.0757659 -64.81567,-64.079666 -64.81567,-64.079666 -64.812069,-64.079666 -64.808468,-64.079666 -64.804867,-64.079666 -64.801266,-64.079666 -64.797665,-64.079666 -64.794064,-64.079666 -64.790463,-64.079666 -64.786862,-64.079666 -64.783261,-64.079666 -64.77966))"], "date_created": "Tue, 01 Jan 2013 00:00:00 GMT", "description": "Light quality and availability are likely to change in polar ecosystems as ice coverage and thickness decrease. How microbes adjust to these and other changes will have huge impacts on the polar marine ecosystems. Little is known about photoheterotrophic prokaryotes, which are hypothesized to gain a metabolic advantage by harvesting light energy in addition to utilizing dissolved organic matter (DOM). Photoheterotrophy is not included in current models of carbon cycling and energy flow. This research will examine three questions: 1. Are photoheterotrophic microbes present and active in Antarctic waters in winter and summer? 2. Does community structure of photoheterotrophs shift between summer and winter? 3. Which microbial groups assimilate more DOM in light than in the dark? The research will test hypotheses about activity of photoheterotrophs in winter and in summer, shifts in community structure between light and dark seasons and the potentially unique impacts of photoheterotrophs on biogeochemical processes in the Antarctic. The project will directly support a graduate student, will positively impact the NSF REU program at the College of Marine and Earth Studies, and will include students from the nation\u0027s oldest historical minority college. The results will be featured during weekly tours of Lewes facilities (about 1000 visitors per year) and during Coast Day, an annual open-house that attracts about 10,000 visitors.", "east": -64.040665, "geometry": ["POINT(-64.0601655 -64.797665)"], "keywords": "Antarctic Peninsula; Biota; LTER Palmer Station; Microbiology; Oceans; Southern Ocean", "locations": "Antarctic Peninsula; Southern Ocean", "north": -64.77966, "nsf_funding_programs": null, "persons": "Cottrell, Matthew; Kirchman, David", "project_titles": "Photoheterotrophic Microbes in the West Antarctic Peninsula Marine Ecosystem", "projects": [{"proj_uid": "p0000473", "repository": "USAP-DC", "title": "Photoheterotrophic Microbes in the West Antarctic Peninsula Marine Ecosystem"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -64.81567, "title": "Photoheterotrophic Microbes in the West Antarctic Peninsula Marine Ecosystem", "uid": "600097", "west": -64.079666}, {"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": "0125794 Price, P. Buford", "bounds_geometry": ["POINT(148.816667 -81.65)"], "date_created": "Wed, 29 Jul 2009 00:00:00 GMT", "description": "This data set contains high-resolution logs of dust and microbes measured at the Siple Dome A borehole in Antarctica. The data were obtained using a newly developed optical borehole logger, which fits into a fluid-filled borehole in glacial ice. It can detect dust and microbes in ice out to several meters from the borehole, and measure optical properties of those particles. The data set contains information on depth and optical signal. Data are available via FTP in data file format (.dat).", "east": 148.816667, "geometry": ["POINT(148.816667 -81.65)"], "keywords": "Antarctica; Dust; Geology/Geophysics - Other; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Microbiology; Optical Backscatter", "locations": "Antarctica", "north": -81.65, "nsf_funding_programs": "Antarctic Glaciology", "persons": "Bay, Ryan", "project_titles": "Optical Logging for Dust and Microbes in Boreholes in Glacial Ice", "projects": [{"proj_uid": "p0000156", "repository": "USAP-DC", "title": "Optical Logging for Dust and Microbes in Boreholes in Glacial Ice"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -81.65, "title": "Optical Logging for Dust and Microbes in Boreholes in Glacial Ice", "uid": "609403", "west": 148.816667}, {"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": "0742057 Gallager, Scott", "bounds_geometry": ["POLYGON((-168.291 -64.846,-165.018 -64.846,-161.745 -64.846,-158.472 -64.846,-155.199 -64.846,-151.926 -64.846,-148.653 -64.846,-145.38 -64.846,-142.107 -64.846,-138.834 -64.846,-135.561 -64.846,-135.561 -66.0269,-135.561 -67.2078,-135.561 -68.3887,-135.561 -69.5696,-135.561 -70.7505,-135.561 -71.9314,-135.561 -73.1123,-135.561 -74.2932,-135.561 -75.4741,-135.561 -76.655,-138.834 -76.655,-142.107 -76.655,-145.38 -76.655,-148.653 -76.655,-151.926 -76.655,-155.199 -76.655,-158.472 -76.655,-161.745 -76.655,-165.018 -76.655,-168.291 -76.655,-168.291 -75.4741,-168.291 -74.2932,-168.291 -73.1123,-168.291 -71.9314,-168.291 -70.7505,-168.291 -69.5696,-168.291 -68.3887,-168.291 -67.2078,-168.291 -66.0269,-168.291 -64.846))"], "date_created": "Thu, 01 Jan 2009 00:00:00 GMT", "description": "The research will continue and extend the study in the Southern Ocean that was initiated during the Oden Southern Ocean 2006 expedition in collaboration with Swedish scientist Mellissa Chierici. We will quantify carbon flux through the food web in the marginal ice zone (MIZ) by measuring size fractionated primary and secondary production, grazing and carbon flux through nanoplankton (2-20 um), microplankton (20-200um), and mesoplankton (200-2000 um). Community structure, species abundance and size specific grazing rates will be quantified using a variety of techniques both underway and at ice stations along the MIZ. The proposed cruise track extends across the Drake Passage to the Western Antarctic Peninsula (WAP) with three station transects along a gradient from the open ocean through the marginal ice zone (MIZ) in the Bellinghausen and Amundsen Seas and into the Ross Sea Polynya. Ice stations along each transect will provide material to characterize production associated with annual ice. Underway measurements of primary and secondary production (chlorophyll, CDOM, microplankton, and mesoplankton) and hydrography (temperature, salinity, pH, DO, turbidity) will establish a baseline for future cruises and as support for other projects such as biogeochemical studies on carbon dioxide drawdown and trace metal work on primary production. The outcome of these measurements will be a description of nano to mesoplankton standing stocks, community structure, and carbon flux along the MIZ in the Bellinghausen and Amundsen Seas and the Ross Sea Polynya.", "east": -135.561, "geometry": ["POINT(-151.926 -70.7505)"], "keywords": "Amundsen Sea; Biota; Microbiology; Navigation; Oceans; Oden; OSO2007; Sample/collection Description; Sample/Collection Description; Southern Ocean", "locations": "Amundsen Sea; Southern Ocean", "north": -64.846, "nsf_funding_programs": null, "persons": "Dennett, Mark; Gallager, Scott", "project_titles": "SGER: Primary and Secondary Production and Carbon Flux Through the Microbial Community Along the Western Antarctic Marginal Ice Zone on the Oden Southern Ocean 2007 Expeditions", "projects": [{"proj_uid": "p0000563", "repository": "USAP-DC", "title": "SGER: Primary and Secondary Production and Carbon Flux Through the Microbial Community Along the Western Antarctic Marginal Ice Zone on the Oden Southern Ocean 2007 Expeditions"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -76.655, "title": "SGER: Primary and Secondary Production and Carbon Flux Through the Microbial Community Along the Western Antarctic Marginal Ice Zone on the Oden Southern Ocean 2007 Expeditions", "uid": "600086", "west": -168.291}, {"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}]
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Dataset Title/Abstract/Map | NSF Award(s) | Date Created | PIs / Scientists | Project Links | Abstract | Bounds Geometry | Geometry | Selected | Visible |
---|---|---|---|---|---|---|---|---|---|
UPLC-Q-TOF data of Cotton Glacier exometabolites
|
1141978 |
2018-03-23 | Foreman, Christine; Tigges, Michelle; Bothner, Brian |
Multidimensional "omics" characterization of microbial metabolism and dissolved organic matter in Antarctica |
Mass spectra of external metabolites were obtained with a 1290 Ultra Performance Liquid Chromatography system coupled to a 6538 Ultra High Definition Accurate-Mass Quadrupole-Time of Flight mass spectrometer operated in positive mode with an electrospray ionization source (Agilent Technologies). 30 mL of filtered media was concentrated per sample by solid phase extraction. External metabolites were re-suspended in 50% (v/v) acetonitrile, and were separated using a reverse-phase Kinetix 1.7 um C18, 100A, 150 mm - 2.1 mm column. Data presented are from UPLC-Q-TOF measurements of mass to charge ratio, retention time, and replicate-averaged extracted ion chromatogram abundance values (counts) of molecular species that demonstrated a significant change in abundance (Two-way ANOVA, adjusted P<0.01) during incubations based on time point (T0: d0, T1: d27, T2: d63, T3: d98) and carbon source (Cotton Glacier: CG, Pony Lake: PL, Suwannee River: SR). | ["POLYGON((161.1667 -77.117,161.21673 -77.117,161.26676 -77.117,161.31679 -77.117,161.36682 -77.117,161.41685 -77.117,161.46688 -77.117,161.51691 -77.117,161.56694 -77.117,161.61697 -77.117,161.667 -77.117,161.667 -77.117,161.667 -77.117,161.667 -77.117,161.667 -77.117,161.667 -77.117,161.667 -77.117,161.667 -77.117,161.667 -77.117,161.667 -77.117,161.667 -77.117,161.61697 -77.117,161.56694 -77.117,161.51691 -77.117,161.46688 -77.117,161.41685 -77.117,161.36682 -77.117,161.31679 -77.117,161.26676 -77.117,161.21673 -77.117,161.1667 -77.117,161.1667 -77.117,161.1667 -77.117,161.1667 -77.117,161.1667 -77.117,161.1667 -77.117,161.1667 -77.117,161.1667 -77.117,161.1667 -77.117,161.1667 -77.117,161.1667 -77.117))"] | ["POINT(161.41685 -77.117)"] | false | false |
LARISSA: Impact of ice-shelf loss on geochemical profiles and microbial community composition in marine sediments of the Larsen A embayment, Antarctic Peninsula
|
0732917 |
2017-12-17 | McCormick, Michael |
Collaborative Research in IPY: Abrupt Environmental Change in the Larsen Ice Shelf System, a Multidisciplinary Approach - Marine Ecosystems. |
Ice-shelf loss along the east coast of the Antarctic Peninsula over recent decades has brought new sources of carbon and energy to the marine benthos likely affecting sediment geochemistry and microbial community composition. To better understand the long-term effects of ice-shelf loss on benthic microbial communities, we conducted a five-station survey along a 160 km transect following the historic path of retreat of the Larsen A ice shelf. All microbial community sequence data is publicly available through the Metagenomics Analysis Server at Argonne National Laboratory (MG-RAST). The project title is "Impact of ice-shelf loss on geochemical profiles and microbial community composition in marine sediments of the Larsen A embayment, Antarctic Peninsula". A key word search using terms from this title at the MG-RAST portal (http://metagenomics.anl.gov/) will return the complete sample list. This submitted dataset summarizes the measured environmental parameters for these same samples (lat., long., water depth, sediment depth, pH, alkalinity, dissolved oxygen, silicate, phosphate, nitrate, nitrite, and ammonium). | ["POLYGON((299.4 -63.1,299.92 -63.1,300.44 -63.1,300.96 -63.1,301.48 -63.1,302 -63.1,302.52 -63.1,303.04 -63.1,303.56 -63.1,304.08 -63.1,304.6 -63.1,304.6 -63.29,304.6 -63.48,304.6 -63.67,304.6 -63.86,304.6 -64.05,304.6 -64.24,304.6 -64.43,304.6 -64.62,304.6 -64.81,304.6 -65,304.08 -65,303.56 -65,303.04 -65,302.52 -65,302 -65,301.48 -65,300.96 -65,300.44 -65,299.92 -65,299.4 -65,299.4 -64.81,299.4 -64.62,299.4 -64.43,299.4 -64.24,299.4 -64.05,299.4 -63.86,299.4 -63.67,299.4 -63.48,299.4 -63.29,299.4 -63.1))"] | ["POINT(-58 -64.05)"] | false | false |
Prokaryotic cell concentration record from the WAIS Divide ice core
|
0839075 |
2017-12-12 | Santibanez, Pamela; Priscu, John |
Collaborative Research: Integrated High Resolution Chemical and Biological Measurements on the Deep WAIS Divide Core |
This data set includes raw concentration of prokaryotic cells for the WAIS Divide deep core, WDC06A, from 1,764 m to 2,709 m. Data were collected by a method that combines acquisition of discrete samples using a continuous ice-core melting system (McConnell et al., 2002) coupled with flow cytometry of DNA-stained samples. The method is described in detail in Santibanez et al., 2016. We present the first long-term, highly resolved prokaryotic cell concentration record obtained from a polar ice core. This record, obtained from the West Antarctic Ice Sheet (WAIS) Divide (WD) ice core, spanned from the Last Glacial Maximum (LGM) to the early Holocene (EH) and showed distinct fluctuations in prokaryotic cell concentration coincident with major climatic states. This record provided strong evidence that airborne prokaryotic cell deposition differed during the LGM, LDG and EH, and that these changes in cell densities could be explained by different environmental conditions during each of these climatic periods. Our observations provide the first ice core time-series evidence for a prokaryotic response to long-term climatic and environmental processes. | ["POINT(-112 -79)"] | ["POINT(-112 -79)"] | false | false |
The Biogeochemical Evolution of Dissolved Organic Matter in a Fluvial System on the Cotton Glacier, Antarctica
|
0838970 |
2014-01-01 | Foreman, Christine |
Collaborative Research: The Biogeochemical Evolution of Dissolved Organic Matter in a Fluvial System on the Cotton Glacier, Antarctica |
Dissolved organic matter (DOM) comprises a significant pool of Earth's organic carbon that dwarfs the amount present in living aquatic organisms. The properties and reactivity of DOM are not well defined, and the evolution of autochthonous DOM from its precursor materials in freshwater has not been observed. Recent sampling of a supraglacial stream formed on the Cotton Glacier in the Transantarctic Mountains revealed DOM that more closely resembles an assemblage of recognizable precursor organic compounds, based upon its UV-VIS and fluorescence spectra. It is suggested that the DOM from this water evolved over time to resemble materials present in marine and many inland surface waters. The transient nature of the system i.e., it reforms seasonally, also prevents any accumulation of the refractory DOM present in most surface waters. Thus, the Cotton Glacier provides us with a unique environment to study the formation of DOM from precursor materials. An interdisciplinary team will study the biogeochemistry of this progenitor DOM and how microbes modify it. By focusing on the chemical composition of the DOM as it shifts from precursor material to the more humified fractions, the investigators will relate this transition to bioavailability, enzymatic activity, community composition and microbial growth efficiency. This project will support education at all levels, K-12, high school, undergraduate, graduate and post-doc and will increase participation by under-represented groups in science. Towards these goals, the investigators have established relationships with girls' schools and Native American programs. Additional outreach will be carried out in coordination with PolarTREC, PolarPalooza, and if possible, an Antarctic Artist and Writer. | ["POINT(161.667 -77.117)"] | ["POINT(161.667 -77.117)"] | false | false |
Alternative Nutritional Strategies in Antarctic Protists
|
0838955 |
2013-01-01 | Gast, Rebecca |
Collaborative Research: Alternative Nutritional Strategies in Antarctic Protists |
This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5). Most organisms meet their carbon and energy needs using photosynthesis (phototrophy) or ingestion/assimilation of organic substances (heterotrophy). However, a nutritional strategy that combines phototrophy and heterotrophy - mixotrophy - is geographically and taxonomically widespread in aquatic systems. While the presence of mixotrophs in the Southern Ocean is known only recently, preliminary evidence indicates a significant role in Southern Ocean food webs. Recent work on Southern Ocean dinoflagellate, Kleptodinium, suggests that it sequesters functional chloroplasts of the bloom-forming haptophyte, Phaeocystis antarctica. This dinoflagellate is abundant in the Ross Sea, has been reported elsewhere in the Southern Ocean, and may have a circumpolar distribution. By combining nutritional modes. mixotrophy may offer competitive advantages over pure autotrophs and heterotrophs. The goals of this project are to understand the importance of alternative nutritional strategies for Antarctic species that combine phototrophic and phagotrophic processes in the same organism. The research will combine field investigations of plankton and ice communities in the Southern Ocean with laboratory experiments on Kleptodinium and recently identified mixotrophs from our Antarctic culture collections. The research will address: 1) the relative contributions of phototrophy and phagotrophy in Antarctic mixotrophs; 2) the nature of the relationship between Kleptodinium and its kleptoplastids; 3) the distributions and abundances of mixotrophs and Kleptodinium in the Southern Ocean during austral spring/summer; and 4) the impacts of mixotrophs and Kleptodinium on prey populations, the factors influencing these behaviors and the physiological conditions of these groups in their natural environment. The project will contribute to the maintenance of a culture collection of heterotrophic, phototrophic and mixotrophic Antarctic protists that are available to the scientific community, and it will train graduate and undergraduate students at Temple University. Research findings and activities will be summarized for non-scientific audiences through the PIs' websites and through other public forums, and will involve middle school teachers via collaboration with COSEE-New England. | ["POLYGON((71.504166 -76.159164,71.5142214 -76.159164,71.5242768 -76.159164,71.5343322 -76.159164,71.5443876 -76.159164,71.554443 -76.159164,71.5644984 -76.159164,71.5745538 -76.159164,71.5846092 -76.159164,71.5946646 -76.159164,71.60472 -76.159164,71.60472 -76.2018032,71.60472 -76.2444424,71.60472 -76.2870816,71.60472 -76.3297208,71.60472 -76.37236,71.60472 -76.4149992,71.60472 -76.4576384,71.60472 -76.5002776,71.60472 -76.5429168,71.60472 -76.585556,71.5946646 -76.585556,71.5846092 -76.585556,71.5745538 -76.585556,71.5644984 -76.585556,71.554443 -76.585556,71.5443876 -76.585556,71.5343322 -76.585556,71.5242768 -76.585556,71.5142214 -76.585556,71.504166 -76.585556,71.504166 -76.5429168,71.504166 -76.5002776,71.504166 -76.4576384,71.504166 -76.4149992,71.504166 -76.37236,71.504166 -76.3297208,71.504166 -76.2870816,71.504166 -76.2444424,71.504166 -76.2018032,71.504166 -76.159164))"] | ["POINT(71.554443 -76.37236)"] | false | false |
The Role of Snow Patches on the Spatial Distribution of Soil Microbial Communities and Biogeochemical Cycling in the Antarctic Dry Valleys
|
0838850 |
2013-01-01 | Gooseff, Michael N. |
Collaborative Research: The Role of Snow Patches on the Spatial Distribution of Soil Microbial Communities and Biogeochemical Cycling in the Antarctic Dry Valleys |
Two models have been proposed to describe controls over microbial biogeography. One model proposes that microbes are ubiquitously distributed across the global environment, and that environmental conditions select for taxa physiologically adapted to local physical conditions. An alternative model predicts that dispersal is the important limitation to the distribution of microorganisms and that spatial heterogeneity of microbial communities is a result of both dispersal and local environmental limitations. According to both models, spatial heterogeneity of microbial communities may be especially pronounced in extreme ecosystems where the environmental selection for organisms with suitable physiology is most strongly manifest. We propose that Antarctic terrestrial environments are ideal places to examine microbial biogeography for 3 reasons: 1) the pristine nature and remoteness of Antarctica minimizes the prevalence of exotic species dispersed through human vectors; 2) the extreme conditions of Antarctic environments provide a strong environmental filter which limits the establishment of non-indigenous taxa; and 3) extreme heterogeneity in the terrestrial environment provides natural gradients of soil conditions (temperature, water and nutrient availability). In the proposed research we will investigate the influence of snow on the composition and spatial distribution of soil microbial communities and linked biogeochemical cycling in the McMurdo Dry Valleys. We will conduct fieldwork at the landscape scale (repeated remote sensing to characterize snow distribution), at the valley and patch scales (quantify snow patch ablation, microbial communities and biogeochemical cycling in subnivian soils). We hypothesize that snow patches play an important role in structuring the spatial distribution of soil microbial communities and their associated ecosystem functioning because of the physical and hydrological influences that snow patches have on the soil environment. The research will contribute to greater public awareness of the importance of polar research to fundamental questions of biology, ecology and hydrology through direct linkages with International Antarctic Institute public outreach activities, including dissemination of web-based learning units on environmental science and microbiology, targeted as resources for secondary and post-secondary educators. Three graduate students, one postdoctoral scholar and multiple undergraduates will participate in the research activities. | ["POLYGON((-163.3 -77.62,-163.202 -77.62,-163.104 -77.62,-163.006 -77.62,-162.908 -77.62,-162.81 -77.62,-162.712 -77.62,-162.614 -77.62,-162.516 -77.62,-162.418 -77.62,-162.32 -77.62,-162.32 -77.631,-162.32 -77.642,-162.32 -77.653,-162.32 -77.664,-162.32 -77.675,-162.32 -77.686,-162.32 -77.697,-162.32 -77.708,-162.32 -77.719,-162.32 -77.73,-162.418 -77.73,-162.516 -77.73,-162.614 -77.73,-162.712 -77.73,-162.81 -77.73,-162.908 -77.73,-163.006 -77.73,-163.104 -77.73,-163.202 -77.73,-163.3 -77.73,-163.3 -77.719,-163.3 -77.708,-163.3 -77.697,-163.3 -77.686,-163.3 -77.675,-163.3 -77.664,-163.3 -77.653,-163.3 -77.642,-163.3 -77.631,-163.3 -77.62))"] | ["POINT(-162.81 -77.675)"] | false | false |
Photoheterotrophic Microbes in the West Antarctic Peninsula Marine Ecosystem
|
0838830 |
2013-01-01 | Cottrell, Matthew; Kirchman, David |
Photoheterotrophic Microbes in the West Antarctic Peninsula Marine Ecosystem |
Light quality and availability are likely to change in polar ecosystems as ice coverage and thickness decrease. How microbes adjust to these and other changes will have huge impacts on the polar marine ecosystems. Little is known about photoheterotrophic prokaryotes, which are hypothesized to gain a metabolic advantage by harvesting light energy in addition to utilizing dissolved organic matter (DOM). Photoheterotrophy is not included in current models of carbon cycling and energy flow. This research will examine three questions: 1. Are photoheterotrophic microbes present and active in Antarctic waters in winter and summer? 2. Does community structure of photoheterotrophs shift between summer and winter? 3. Which microbial groups assimilate more DOM in light than in the dark? The research will test hypotheses about activity of photoheterotrophs in winter and in summer, shifts in community structure between light and dark seasons and the potentially unique impacts of photoheterotrophs on biogeochemical processes in the Antarctic. The project will directly support a graduate student, will positively impact the NSF REU program at the College of Marine and Earth Studies, and will include students from the nation's oldest historical minority college. The results will be featured during weekly tours of Lewes facilities (about 1000 visitors per year) and during Coast Day, an annual open-house that attracts about 10,000 visitors. | ["POLYGON((-64.079666 -64.77966,-64.0757659 -64.77966,-64.0718658 -64.77966,-64.0679657 -64.77966,-64.0640656 -64.77966,-64.0601655 -64.77966,-64.0562654 -64.77966,-64.0523653 -64.77966,-64.0484652 -64.77966,-64.0445651 -64.77966,-64.040665 -64.77966,-64.040665 -64.783261,-64.040665 -64.786862,-64.040665 -64.790463,-64.040665 -64.794064,-64.040665 -64.797665,-64.040665 -64.801266,-64.040665 -64.804867,-64.040665 -64.808468,-64.040665 -64.812069,-64.040665 -64.81567,-64.0445651 -64.81567,-64.0484652 -64.81567,-64.0523653 -64.81567,-64.0562654 -64.81567,-64.0601655 -64.81567,-64.0640656 -64.81567,-64.0679657 -64.81567,-64.0718658 -64.81567,-64.0757659 -64.81567,-64.079666 -64.81567,-64.079666 -64.812069,-64.079666 -64.808468,-64.079666 -64.804867,-64.079666 -64.801266,-64.079666 -64.797665,-64.079666 -64.794064,-64.079666 -64.790463,-64.079666 -64.786862,-64.079666 -64.783261,-64.079666 -64.77966))"] | ["POINT(-64.0601655 -64.797665)"] | 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 |
Optical Logging for Dust and Microbes in Boreholes in Glacial Ice
|
0125794 |
2009-07-29 | Bay, Ryan |
Optical Logging for Dust and Microbes in Boreholes in Glacial Ice |
This data set contains high-resolution logs of dust and microbes measured at the Siple Dome A borehole in Antarctica. The data were obtained using a newly developed optical borehole logger, which fits into a fluid-filled borehole in glacial ice. It can detect dust and microbes in ice out to several meters from the borehole, and measure optical properties of those particles. The data set contains information on depth and optical signal. Data are available via FTP in data file format (.dat). | ["POINT(148.816667 -81.65)"] | ["POINT(148.816667 -81.65)"] | 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 |
SGER: Primary and Secondary Production and Carbon Flux Through the Microbial Community Along the Western Antarctic Marginal Ice Zone on the Oden Southern Ocean 2007 Expeditions
|
0742057 |
2009-01-01 | Dennett, Mark; Gallager, Scott |
SGER: Primary and Secondary Production and Carbon Flux Through the Microbial Community Along the Western Antarctic Marginal Ice Zone on the Oden Southern Ocean 2007 Expeditions |
The research will continue and extend the study in the Southern Ocean that was initiated during the Oden Southern Ocean 2006 expedition in collaboration with Swedish scientist Mellissa Chierici. We will quantify carbon flux through the food web in the marginal ice zone (MIZ) by measuring size fractionated primary and secondary production, grazing and carbon flux through nanoplankton (2-20 um), microplankton (20-200um), and mesoplankton (200-2000 um). Community structure, species abundance and size specific grazing rates will be quantified using a variety of techniques both underway and at ice stations along the MIZ. The proposed cruise track extends across the Drake Passage to the Western Antarctic Peninsula (WAP) with three station transects along a gradient from the open ocean through the marginal ice zone (MIZ) in the Bellinghausen and Amundsen Seas and into the Ross Sea Polynya. Ice stations along each transect will provide material to characterize production associated with annual ice. Underway measurements of primary and secondary production (chlorophyll, CDOM, microplankton, and mesoplankton) and hydrography (temperature, salinity, pH, DO, turbidity) will establish a baseline for future cruises and as support for other projects such as biogeochemical studies on carbon dioxide drawdown and trace metal work on primary production. The outcome of these measurements will be a description of nano to mesoplankton standing stocks, community structure, and carbon flux along the MIZ in the Bellinghausen and Amundsen Seas and the Ross Sea Polynya. | ["POLYGON((-168.291 -64.846,-165.018 -64.846,-161.745 -64.846,-158.472 -64.846,-155.199 -64.846,-151.926 -64.846,-148.653 -64.846,-145.38 -64.846,-142.107 -64.846,-138.834 -64.846,-135.561 -64.846,-135.561 -66.0269,-135.561 -67.2078,-135.561 -68.3887,-135.561 -69.5696,-135.561 -70.7505,-135.561 -71.9314,-135.561 -73.1123,-135.561 -74.2932,-135.561 -75.4741,-135.561 -76.655,-138.834 -76.655,-142.107 -76.655,-145.38 -76.655,-148.653 -76.655,-151.926 -76.655,-155.199 -76.655,-158.472 -76.655,-161.745 -76.655,-165.018 -76.655,-168.291 -76.655,-168.291 -75.4741,-168.291 -74.2932,-168.291 -73.1123,-168.291 -71.9314,-168.291 -70.7505,-168.291 -69.5696,-168.291 -68.3887,-168.291 -67.2078,-168.291 -66.0269,-168.291 -64.846))"] | ["POINT(-151.926 -70.7505)"] | 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 |