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GC-MS > Gas Chromatograph/Mass Spectrometry

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  • Researchers studied persistent organohalogen contaminants (POCs) in the eastern Antarctic sector. Samples were collected during January and February 2006 and originated from 12 sampling stations. They were analysed for greater than 100 organohalogen compounds including chlorinated pesticides, polychlorinated biphenyls (PCBs), polybrominated organic compounds and polychlorinated dibenzo-p-dioxins/furans (PCDD/Fs). The suspected naturally occurring organohalogen, 2,4,6-tribromoanisole (TBA) as well as delta-HCH; o,p'- DDE; o,p'-DDD; p,p'-DDD; p,p'-DDT; penta-chlorobenzene (PeCB); HCB; heptachlor-exoepoxide; heptachlor; trans-nonachlor, mirex and toxaphene congeners Tox-26 (B8-1413), Tox-40+41 (B8-1414+ B8-1945) and Tox-50 (B8-2229) were quantified in all samples analysed whilst PCB-101, gamma-HCH, p,p'-DDE cis-nonachlor, Tox-42a (B8-806) and Tox-44 (B8-2229) were quantified in greater than or equal to 75% of samples analysed. Organochlorine pesticides dominated measured krill contaminant burdens with hexachlorobenzene (HCB) as the single most abundant compound quantified: 4.37 ng/glw (lipid weight) or 0.2 ng/gww (wet weight). HCB concentrations were comparable to those detected at this trophic level in both the Arctic and temperate northwest Atlantic, lending support to the hypothesis that HCB will approach global equilibrium at a faster rate than other POCs. Para, para'-dichlorodiphenylethene (p,p'- DDE) was detected at notable concentrations: 2.6 ng/glw 0.13 ng/gww. In contrast to the Arctic, PCBs did not feature prominently in contaminant burdens of Antarctic krill: 1.2 ng g- 1 lw and 0.05 ng/gww., dominant PCB congeners were PCB-18, PCB-28, PCB-31 and PCB- 153. The major commercial polybrominated diphenyl ether (PBDE) congeners -99 and -47 were quantified at low background levels (0.67 ng/glw , 0.03 ng/gww and 0.35 ng/glw, 0.007 ng/gww respectively) with clear concentration spikes observed at around 70 degrees E , in the vicinity of modern, active research stations. The suspected naturally occurring brominated organic compound, 2,4,6-tribromoanisole (TBA), was a ubiquitous contaminant in all samples 49 whereas the only PCDD/Fs quantifiable were trace levels of octachlorodibenzo-p-dioxin (OCDD) and 1,2,3,4,7,8/1,2,3,4,7,9-hexachlorodibenzofuran (HxCDF). This work has been incorporated in AAS project 3115 (ASAC_3115), Persistent Organic Pollutants and Emerging Contaminants of Concern; System Input From Local and Distant Contamination Sources.

  • These data relate to the Max Easton Honours project, carried out at Macquarie University in 2010, supervised by Simon George THE LONG-TERM DEGRADATION OF LUBRICANT OIL IN ANTARCTIC MARINE SEDIMENTS. A simulated marine spill has been carried out by the Australian Antarctic Division (AAD) over a five year period, in which Antarctic sea-bed sediments were doped with various petroleum products and left in a shallow marine environment to examine the extent and rate of natural degradation. Of these pollutants, unused Mobil lubricant oil (OW/40; Exxon Mobil) was analysed qualitatively and semi-quantitatively by gas chromatography-mass spectroscopy (GC-MS) to determine the composition of the oil and the rates and modes of degradation. The Mobil Lubricant Oil was found to consist of three dominant compound classes; 1) a series of branched alkanes with chain lengths of C25-26 and C33-34, 2) a series of long chain alkylnaphthalenes (formula C26H40), and 3) a series of bulky alkanoate esters. Other minor compounds were also identified. The alkanoate esters were depleted most readily, to less than 20% their initial values after 65 weeks. Branched alkanes and long chain alkylnaphthalenes were both recalcitrant over time, present at ~10% of their initial value after 260 weeks. Both the branched alkanes and long chain alkylnaphthalenes exhibited near identical behaviour through the sediment profile over time, depleting at the surface and increasing at depths consistent with migration through the sediment profile. Branched alkanes were depleted most rapidly relative to all other compounds, perhaps owing to preferred the biodegradation of long alkyl chains. No clear interpretation of the dominant mode of degradation was able to be defined, although it is believed that a multitude of removal mechanisms participate in the removal of lubricant oils in Antarctic marine sediments. 1) Retention time - Minutes 2) Region - It is a retention time window, labelled A to G as colours 3) Peak area - Peak area is in arbitrary units.

  • This metadata record contains the results from bioassays conducted to show the response of the common Antarctic amphipod, Paramoera walkeri to contamination from combinations of Special Antarctic Blend (SAB) diesel, Marine Gas Oil (MGO) and Intermediate Fuel Oil (IFO 180), chemically dispersed with fuel dispersants Ardrox 6120 and Slickgone NS. Fuel only water accommodated fractions (WAF), chemically enhanced water accommodated fractions (CEWAF) and dispersant only treatments were prepared following the methods in Singer et al. (2000) with adaptations from Barron and Ka’aihue (2003). WAF was made using the ratio of 1: 25 (v/v), fuel to filtered seawater (FSW) following the methods of Brown et al. (in prep). Ratios for chemically dispersed treatments were 1: 100 (v/v), fuel to FSW and 1: 20 (v/v) dispersant to fuel. Dispersant only treatments were made using ratios for CEWAF, substituting the fuel component with FSW. Mixes were made in 5 L or 10 L glass aspirator bottles using a magnetic stirrer to achieve a vortex of 20-25% in the FSW before the addition of test media. The same mixing energy was used to prepare all WAFs for enhanced reproducibility and comparability of results (Barron and Ka’aihue, 2003). Mixes were stirred in darkness to prevent bacterial growth for 42 h with an additional settling time of 6 h at 0 plus or minus 1 oC. Extended stirring times were used following the recommendations determined as part of the hydrocarbon chemistry component of this project (Kotzakoulakis, unpublished data). A dilution series of four concentrations were made from the full strength aqueous phase of each mix using serial dilution. WAF test concentrations were 100%, 50%, 20% and 10% while CEWAF concentrations were 10%, 5%, 1% and 0.1%. These concentrations were chosen in order to quantify the mortality curve and allow statistical calculation of LC50 values. To facilitate comparisons of dispersant toxicity in the presence and absence of fuel, dispersant only test concentrations reflected those of CEWAF treatments. WAF was sealed in airtight glass bottles stored at 0 plus or minus 1 oC for a maximum of 3 h before use. Fresh test solutions were prepared every four days to ensure consistent water quality and replace hydrocarbons that adsorbed or evaporated into the atmosphere. Each test concentration was represented by five replicates with five FSW control beakers, with 10 P. walkeri individuals per replicate. Only healthy and active individuals were chosen with a size range of 7.9 plus or minus 0.7 mm for adults and 2.5 plus or minus 0.2 for juveniles measured from the base of the antennae to the widest part of the dorsal curve. Larger individuals and brooding females were not used to avoid unrelated deaths related to age or reproductive state (Sagar, 1980). Beakers were filled to 200 ml and were left open to allow the natural evaporation of lighter monoaromatic hydrocarbon components that would occur during a real spill. A small square of plankton mesh was placed in each jar to provide a substratum to reduce the stress of laboratory conditions and to help to stem cannibalism. Animals were not fed during experiments to avoid hydrocarbons adsorbed onto food pellets being ingested by the amphipods, thereby introducing an additional exposure pathway. Experiments ran for a total of 12 d exposure duration. Experiments were run in cold temperature-controlled cabinets maintained at a temperature of 0 plus or minus 1 oC, fluorescent lights in the cabinets were set to a light regime of 18 h light, 6 h darkness, following the methods in Brown et al. (2017) to reflect Antarctic summer environmental conditions. Lethal and sublethal observations were made at standard ecotoxicology test times of 24 h, 48 h, 96 h, 7 d, 10 d and 12 d, with an additional observation at 8 d coinciding with one of the 4-day water changes. The health status of each individual was classified on a scale of one to four; one showing no effect up to four being mortality. Mortality was determined by a lack of movement and response to stimuli, particularly in the gills. Dead animals were removed and preserved in 80% ethanol at each observation period. Missing amphipods that may have been cannibalised were included in mortality counts as they were likely to have been moribund or already dead when eaten. In order to simulate a repeated pulse pollutant, 90 to 100% of the test solution volume of each beaker was renewed with freshly made test concentrations every four days to replenish hydrocarbons lost through evaporation and adsorption and ensure consistent water quality. Beakers were topped up to 200 ml between water changes with deionised water to maintain water quality parameters. Duplicate 25 ml aliquots of test concentrations were taken at the beginning and end of each experiment in addition to pre and post water change samples. Samples were immediately extracted with 0.7 μm of dichloromethane spiked with an internal standard of BrC20 (1-bromoeicosane) and cyclooctane. Samples were analysed using Gas Chromatography with Flame Ionisation Detection (GC-FID) and mass spectrometry (GC-MS). To determine actual exposure concentrations, four day measured TPH values were used to create a continuous exposure and evaporation profile over the 12 d test period following the methods outlined in Payne et al. (2014) and Brown et al. (2017).

  • Data Acquisition: Sampling was performed on seawater collected from CTDs and minicosm experiments. Sampling involved the collection of 250 mL of seawater from each Niskin bottle and minicosm sampled. 100 mL of this was fixed with 1 mL of concentrated hydrochloric acid (HCl). A second 100 mL sample was filtered through a 0.45 micron filter and then fixed with HCl. The remaining water was filtered and purged, with the volatile gases eluted being trapped on gold wool enclosed in glass tubes. Data Analysis: Analysis of the gold wool tubes involved heating the tubes to separate the dimethylsulphide (DMS) and then purge and trap followed by gas chromatography (GC) to give the DMS concentration of the seawater sample. The fixed water samples and filtered fixed water samples were basified and then the DMS formed during this process was purged, trapped and analysed by GC to determine the dissolved and particulate dimethylsulphoniopropionate (DMSP) concentrations. Analysis is expected to take approximately one year to complete. Dataset Format: The data for the CTD sampling is in the following format - CTD Number; Niskin Bottle; DMS Concentration (nM); DMSP particulate concentration (nM); DMSP dissolved concentration (nM) The data for the minicosm sampling is in the following format: Minicosm Number; Minicosm Day; Hour; Tank Number; DMS Concentration (nM); DMSP particulate concentration (nM); DMSP dissolved concentration (nM) Acronyms Used: CTD - conductivity, temperature, pressure DMS - dimethylsulphide DMSP - dimethylsulphoniopropionate DMSO - dimethylsulphoxide GC - gas chromatography This work was completed as part of ASAC projects 2655 and 2679 (ASAC_2655, ASAC_2679).

  • Untreated, macerated wastewater effluent has been discharged to the sea at Davis Station since 2005, when the old wastewater treatment infrastructure was removed. This environmental assessment was instigated to guide the choice of the most suitable wastewater treatment facility at Davis. The assessment will support decisions that enable Australia to meet the standards set for the discharge of wastewaters in Antarctica in national legislation (Waste Management Regulations of the Antarctic Treaty Environmental Protection Act - ATEP) and to meet international commitments (the Madrid Protocol) and to meet Australia's aspirations to be a leader in Antarctic environmental protection. The overall objective was to provide environmental information in support of an operational infrastructure project to upgrade wastewater treatment at Davis. This information is required to ensure that the upgrade satisfies national legislation (ATEP/Waste Management Regulations), international commitments (the Madrid Protocol) and maintain the AAD's status as an international leader in environmental management. The specific objectives were to: 1. Wastewater properties: Determine the properties of discharged wastewater (contaminant levels, toxicity, microbiological hazards) as the basis for recommendations on the required level of treatment and provide further consideration of what might constitute adequate dilution and dispersal for discharge to the nearshore marine environment 2. Dispersal and dilution characteristics of marine environment: Assess the dispersing characteristics of the immediate nearshore marine environment in the vicinity of Davis Station to determine whether conditions at the existing site of effluent discharge are adequate to meet the ATEP requirement of initial dilution and rapid dispersal. 3. Environmental impacts: Describe the nature and extent of impacts to the marine environment associated with present wastewater discharge practices at Davis and determine whether wastewater discharge practices have adversely affected the local environment. 4. Evaluate treatment options: Evaluate the different levels of treatment required to mitigate and/or prevent various environmental impacts and reduce environmental risks.

  • Metadata record for data expected from ASAC Project 2915 See the link below for public details on this project. Petroleum contamination poses a major threat to Antarctic and subantarctic ecosystems because diesel and lubricants are persistent and, at poorly defined concentrations, are toxic in marine environments. This project will asses how quickly important components in these products are naturally depleted using a model field experiment. We will identify and quantify the non-degrading portions of the fuels, and assess the longevity and rate of removal of these. We will relate the chemical analysis data with biological data on organisms in the sea-bottom sediments, in order to assess which components of the fuels do most harm to the organisms. Project objectives: The overall objective is to better understand the long-term environmental impact of spilled petroleum products in Antarctic marine systems. Decades of Antarctic exploration have left a significant legacy of petroleum pollution on-land and in nearshore marine environments, particularly around human stations. The natural attenuation of spilled diesel and lubricants occurs slowly in cold climates, particularly once the pollutants have adsorbed onto marine sediments. Major programmes funded by the AAD have identified the location of spills, and the nature and fate of some of the pollutants. This project will address some of the significant uncertainties which still exist regarding the natural depletion and ecotoxicological impact of spilled diesel and lubricants in the marine environment. A new PhD student at Macquarie University will carry-out much of this work, in collaboration with the CI and investigators. The specific objectives are: 1. To develop a quantitative method using cutting edge two-dimensional gas chromatography-mass spectrometry (GCxGC-TOFMS) to identify the components of spilled diesel and lubricants, especially the complex mixtures of recalcitrant residues and the secondary products of alteration. 2. To calculate the rates of removal of pollutants in the marine environment by comprehensive statistical treatment of the chemical data-set, and to assess the processes by which this removal occurs (e.g. aerobic/anaerobic biodegradation, water-washing, etc). 3. To assess the degradation rates and longevity of pollutant components against the biology of the disturbed communities of microbes and microfauna in the same experiments, so as to form a hypothesis of which components of the complex mixtures have the most important ecotoxicological response and environment impact. 4. Using the most important single isolated or related groups of components, to test the specific ecotoxicological impact of each in the marine environment using a short-term field experiment and laboratory toxicity tests. Taken from the 2008-2009 Progress Report: Progress against objectives: 1. A GCxGC-FID was installed at Macquarie University. No TOFMS has been purchased yet, due to non-funding of ARC Lief grant application. No further progress made towards this objective. 2. We have a comprehensive dataset now of the rates of removal of hydrocarbon components of SAB from the SRE4 experiment. Detailed GC-MS has been carried out so as to track removal of components in much more detail than can be achieved by GC-FID alone. TPH data have been calculated. The data has been utilised in the draft of one paper by Shane Powell (Powell, Stark, Snape, Woolfenden, Bowman, Riddle; Effects of diesel and lubricant oils on Antarctic benthic microbial communities over five years) which has not been submitted yet, and in an early draft of a paper by PhD student Ellen Woolfenden (E. N. M. Woolfenden, G. Hince, S. Powell, S. Stark, J. Stark, I. Snape, S. George; Effects of diesel and lubricant oils on Antarctic benthic microbial communities over five years). 3. This has partly been done, and is being written up by the Powell et al. paper referred to above. Detailed analysis of which are the most toxic compounds of SAB awaits further work-up of the data. 4. The field season to carry out this test was postponed from 08/09 to 09/10. Taken from the 2009-2010 Progress Report: Progress against objectives: 1. An ARC LIEF grant application was successful and a TOFMS will be purchased from the funds gained in mid 2010. 2. So far the 0-1cm of 10cm cores of marine sediment spiked with Biodegradable lubricant, used lubricant, clean lubricant and Special Antarctic Blend (SAB) diesel have been analysed by gas chromatography coupled to a flame ionisation detector (GC-FID). Analyses by GC-FID allowed the Total Petroleum Hydrocarbon (TPH) concentration at each sample time to be calculated from statistical analysis. Further analyses were performed on the SAB sediments extractions by GC-MS (mass spectrometry). The chromatograms of the extractions were compared with chromatograms of standard mixtures of compounds and a compound identification library and thus, peaks were identified. From this peak identification, degradation patterns of compounds and groups of compounds could be seen; naphthalenes degrade less readily with increasing methyl groups but still degrade more readily than n-alkanes. From the analyses of the 0-1cm sediment extractions the most recalcitrant compounds were (adamantanes and diamantanes) and the most water soluble compounds were (naphthalenes and alkylnaphthalenes) in SAB diesel. The data has been written up in a draft paper by PhD student Ellen Woolfenden (E. N. M. Woolfenden, G. Hince, S. Powell, S. Stark, J. Stark, I. Snape, S. George; Effects of diesel and lubricant oils on Antarctic benthic microbial communities over five years). This paper will be submitted by May 2010. We also have started analysing the depth profiles for SAB in the SRE4 experiment. It is interesting to know as to whether any biodegradation patterns will be seen in the 1-10 cm depths of the sediment. Therefore the cores have been sectioned into 1 cm intervals and extracted at AAD. The extractions are awaiting analysis by GC-FID initially and GC-MS for further analysis. 3. This has partly been done, and is being written up by a Shane Powell et al. paper, that has not been published yet. Detailed analysis of which are the most toxic compounds of SAB awaits further work-up of the data. 4. The field season to carry out this test was carried out by Ellen Woolfenden in fieldseason 09/10. Samples have been collected and are stored at AAD. Marine sediment was collected and different portions were spiked with certain compounds from each of these groups as well as a selection of n-alkanes and SAB diesel as a comparison. These sediments have been extracted and are awaiting analysis by GC-MS to identify which of the compounds are depleted most readily within the experimental groups without the influence of other compounds present in SAB diesel. Ellen will be analysing them later in 2010. The dataset provided by Ellen Woolfenden contain a number of excel spreadsheets, as well as a word document providing further information about the data.

  • This metadata record contains the results from bioassays conducted to show the response of an Antarctic nemertean Antarctonemertes unilineata to contamination from combinations of Special Antarctic Blend (SAB) diesel, Marine Gas Oil (MGO) and Intermediate Fuel Oil (IFO 180), chemically dispersed with fuel dispersants Ardrox 6120, Slickgone LTSW and Slickgone NS. Note that the corresponding PhD thesis chapter refers to the species as Antarctonemertes sp., prior to being named Antarctonemertes unilineata in 2018. Experiments using SAB, MGO and IFO 180 with the dispersant Ardrox 6120, including fuel only and dispersant only treatments were conducted at Casey station. Experiments involving IFO 180 and the fuel dispersants Slickgone LTSW and Slickgone NS were conducted at the Antarctic Division’s Marine Research Facility quarantine labs. All experimental procedures, including test mix preparation and bioassays were conducted at 0 plus or minus 1 degree C. Water accommodated fractions (WAF; fuel mixed in water) and chemically enhanced water accommodated fractions (CEWAF) were made according to the specifications of Singer, Aurand et al. (2000), Barron and Ka’aihue (2003) and Kotzakoulakis (unpublished at time of writing). Dispersant only mixes were also made using filtered seawater (FSW) and dispersant volumes proportional to those used for CEWAF production. WAF was made using a loading ratio of 1: 25 (v/v) fuel to FSW, CEWAF was prepared using 1:100 (v/v) fuel to FSW ratio, and 1: 20 (v/v) dispersant to fuel ratio. Following the 48 h preparation time, the seawater WAF components of the mix were drained from the bottom of aspirator bottles and serially diluted. WAF treatment concentrations were 100%, 50%, 20% and 10%, CEWAF and dispersant only concentrations were 10%, 5%, 1% and 0.1%. Treatment solutions were replenished every four days to simulate a repeated pulse exposure to contaminants and to replace hydrocarbons lost through evaporation and adsorption and to maintain water quality parameters. WAF, CEWAF and dispersant only test solutions were remade every four days using identical methods. Tests were done in temperature-controlled cabinets set to 0 plus or minus 1 degree C following a 6 h light to 18 h dark photoperiod. Beakers were left uncovered to allow for the natural evaporation of lighter hydrocarbon components to reflect real fuel spill conditions. Experiments ran for 24 d except for the Ardrox 6120 only experiment, which ran for 16 d due to high mortality in this treatment. Sublethal and lethal endpoints were assessed at 1, 2, 4, 7, 8, 12, 14, 16, 20 and 24 d observations. Aliquot water samples for analysis of total hydrocarbon content (THC) were taken for initial and final test concentrations, and before and after each four-day water change, to obtain accurate profiles of hydrocarbon loss over the test period. Duplicate samples were taken for every treatment concentration and extracted with dichloromethane, spiked with an internal standard of 1-bromoeicosane and cyclooctane. Samples were analysed using gas chromatography with flame ionization detection (GC-FID) and gas chromatography mass spectrometry (GC-MS). Average THC concentrations for the duration of the experiment were obtained by integrating the measured concentrations to which animals were exposed following the methods of Brown et al. (2016) and Payne et al. (2014). This data submission includes one file detailing the TPH experiment analyses and one detailing the bioassay tests and results. The thesis that relates to this work is available from: https://epubs.scu.edu.au/theses/533/

  • Metadata record for data from ASAC Project 867 See the link below for public details on this project. Dataset Sea-ice bacteria data are associated with ASAC_1012 and included there Data for bacteria from ornithogenic soil samples collected from the Vestfold Hills Region is included (associated with ref 9899): 1) Isolate designations, availability, media used and growth conditions. 2) Phenotypic data - morphology, nutritional and biochemical traits 3) Chemical data - fatty acids, wax esters 4) Genotypic data - DNA base composition, DNA:DNA hybridisation analysis 5) Phylogenetic data - 16S rRNA gene sequences The download file contains: Sample data obtained. Includes sea-ice sampling sites, location, information on ice cores including presence or absence of algal assemblage band communities and whether under-ice seawater was collected or not. Samples were melted and/or melted then filtered (0.2 micron size) for cultivation and DNA-related analyses carried out primarily in AAS project 1012.

  • ---- Public Summary from Project ---- The lakes and fjords of the Vestfold Hills region of Antarctica provide unique ecosystems for studying environmental changes in Antarctica over the past 8000 years. Studies of the changes in organic matter composition in sediment cores provide information how the microbial and plankton communities have changed over time in response to varying chemical and physical conditions. Our study will provide new information about how the cycles of the biologically-important elements carbon and sulfur are linked and why some sediments can preserve large amounts of organic carbon. This information will be useful for studies of palaeoclimate and will also provide valuable insights into the processes that produce petroleum source rocks. From the abstracts of the referenced papers: Preserved ribosomal DNA of planktonic phototrophic algae was recovered from Holocene anoxic sediments of Ace Lake (Antarctica), and the ancient community members were identified based on comparative sequence analysis. The similar concentration profiles of DNA of haptophytes and their traditional lipid biomarkers (alkenones and alkenoates) revealed that fossil rDNA also served as quantitative biomarkers in this environment. The DNA data clearly revealed the presence of six novel phylotypes related to known alkenone and alkenoate-biosynthesising haptophytes with Isochrysis galbana UIO 102 as their closest relative. The relative abundance of these phylotypes changed as the lake chemistry, particularly salinity, evolved over time. Changes in the alkenone distributions reflect these population changes rather than a physiological response to salinity by a single halophyte. Using this novel palaeo-ecological approach of combining data from lipid biomarkers and preserved DNA, we showed that the post-glacial development of Ace Lake from freshwater basin to marine inlet and the present-day lacustrine saline system caused major qualitative and quantitative changes in the biodiversity of the planktonic populations over time. Post-glacial Ace Lake (Vestfold Hills, Antarctica), which was initially a freshwater lake and then an open marine system, is currently a meromictic basin with anoxic, sulfidic and methane-saturated bottom waters. Lipid and 16S ribosomal RNA gene stratigraphy of up to 10,400-year-old sediment core samples from the lake revealed that these environmentally induced chemical and physical changes caused clear shifts in the species composition of archaea and aerobic methanotrophic bacteria. The combined presence of lipids specific for methanogenic archaea and molecular remains of aerobic methanotrophic bacteria (13C-depleted delta8(14)-sterols and 16S rRNA genes) revealed that an active methane cycle occurred in Ace Lake during the last 3000 calendar years and that the extant methanotrophs were most likely introduced when it became a marine inlet (9400 y BP); rDNA sequences showed 100% sequence similarity with Methanosarcinales species from freshwater environments and were the source of sn-2- and sn3-hydroxyarchaeols. Archaeal phylotypes related to uncultivated Archaea associated with various marine environments were recovered from the present-day anoxic water column and sediments deposited during the meromictic and marine period.

  • The data set includes information relevant for the study and description of sea-ice bacteria contains the following dataset subgroups and is organised by REFERENCE number. 1) Isolation data: strain designations (e.g. culture collection names are indicated for type cultures); media used for isolation and routine cultivation; temperature used for incubation; any special conditions (e.g. enrichment conditions) used for isolation; isolation site and type (e.g. sea-ice); availability of the indicated strain from the chief investigator (J. Bowman) 2) Phenotypic data: Includes morphological, physiological and biochemical tests performed. Details on how these were performed are indicated in the relevant reference. 3) Growth/temperature data: data for temperature related growth curves are given where available. Methods are indicated in the associated reference. 4) Fatty acid/chemotaxonomy data: fatty acid and other related data are given where available. Methods are indicated in the associated reference. 5) Genotypic data: data for DNA-guanosine/cytosine-content and genomic DNA:DNA hybridization are shown where available. Methods are indicated in the associated reference. 6) Phylogenetic data: data for sequences are cross-referenced to the GenBank database. In some cases, aligned sequence datasets are available in FASTA format and can be viewed in the programs BIOEDIT (www.mbio.ncsu.edu/BioEdit/bioedit.html) or CLUSTAL W (www.ebi.ac.uk/clustalw). 7) Other related published references which are useful or relevant to the dataset e.g. related sequences published subsequent to the ASAC study