Exopolysaccharide (EPS) is complex sugar made by many microbes in the Antarctic marine environment. This project seeks to understand the ecological role of microbial EPS in the Southern Ocean, where it is known to strongly influence primary production. We will investigate the chemical composition and structure of EPS obtained from Antarctic microbes, which will improve our knowledge of its ecological significance and biotechnological potential. Dataset includes the following: 1) Information on Exopolysaccharide-producing bacterial isolates, isolation sites, media used and growth conditions. 2) 16S rRNA gene sequence and fatty acid data of isolates for strain identification. 3) Exopolysaccharide chemistry data including EPS carbohydrate composition, organic acid composition, sulfate content, molecular weight. 4) Physiology of exopolysaccharide synthesis. Effects of temperature and other factors on EPS yield and glucose conversion efficiency. 5) Iron binding properties. The download file includes: 11 files File 1. Bacterial isolate 16S rRNA gene sequences obtained from Southern Ocean seawater or ice samples. The sequences are all deposited on the GenBank nucleotide (NCBI) database. Sequences are in FASTA format. File 2. Seawater and sea-ice sample information including sites samples, sample type. File 3. Data for exopolysaccharide (EPS)-producing bacteria isolated and subsequently selected for further studied. Information indicates special treatments used to obtain strains including plankton towing, filtration method, and enrichment. Identification to species level was determined by 16S rRNA gene sequence analysis. File 4. EPS-producing bacterial isolate fatty acid content determined using GC/MS procedures. File 5. Basic chemical data for EPS from Antarctic isolates including protein, sulfate, and sugar type relative content (determined by chemical procedures), molecular weight in kilodaltons and polydispersity (determined by gel-based molecular seiving). File 6 Monosaccharide unit composition determined by GC/MS of EPS from Antarctic isolates. File 7. Effect of temperature on culture viscosity and growth of EPS-producing bacterium Pseudoalteromonas sp. CAM025 as affected by temperature. File 8. Effect of temperature on EPS and cell yields and EPS synthesis efficiency (as indicated by glucose consumption) of EPS-producing bacterium Pseudoalteromonas sp. CAM025 as affected by temperature. File 9. Efficiency of copper and cadmium metal ion adsorption onto EPS from EPS-producing bacterium Pseudoalteromonas sp. CAM025. File 10. Phenotypic characteristics data for novel EPS-producing Antarctic strain CAM030. Represents type strain of Olleya marilimosa. File 11. Effect of temperature on chemical make up of EPS from EPS-producing bacterium Pseudoalteromonas sp. CAM025.

This work was completed as part of the SIPEX - Sea Ice Physics and Ecosystem eXperiment - voyage. Adapted from the SIPEX website: During SIPEX we investigated the biogeochemistry of iron (Fe), including a comprehensive examination of its distribution, speciation (i.e. the different forms of Fe), cycling and its role in fuelling sea ice-based and pelagic algal communities. A major part of this research concentrated on the influence of organic exopolysaccharides (EPS) on Fe solubility and its bio-availability. The distribution of other bioactive trace elements was also examined as a means of fingerprinting the source(s) of Fe, as well as indicating their biological requirements. ######### Data on the small- to medium scale (0.1-1000 m) spatial and temporal distribution of Fe and EPS in sea ice cores, surface snow, brine and underlying seawater were determined in each sampled medium by the interdisciplinary team working on the SIPEX project (AAS 3026) in the East Antarctic sector in September/October 2007. Data include Chlorophyll a, salinity, temperature, sea-ice thickness, ice texture analysis, macro-nutrients (nitrate, phosphate, silicate), oxygen stable isotopes, POC and DOC, EPS, iron. This work was completed as part of AAS (ASAC) project 3026. See the parent metadata record (ASAC_3026) for more information.

Metadata record for data from AAS (ASAC) project 3026. Public This project will assess the importance of the trace micro-nutrient element iron to Antarctic sea-ice algal communities during the International Polar Year (2007-2009). We will investigate the biogeochemistry of iron, including a comprehensive examination of its distribution, speciation, cycling and role in fuelling ice-edge phytoplankton blooms. A significant part of this research will concentrate on the the influence of organic exopolysaccharides on iron solubility, complexation and bioavailability, both within the ice and in surrounding snow and surface seawater. This innovative research will improve our understanding of key processes that control the productivity of the climatically-important Antarctic sea-ice zone. Project objectives: This project will assess the importance of the trace element iron (Fe) as a micro-nutrient to seasonal sea-ice algal communities in the Australian sector of Antarctica during the International Polar Year (2007-09). We will investigate the biogeochemistry of Fe, including a comprehensive examination of its distribution, speciation, cycling and role in fuelling ice-edge phytoplankton blooms. A significant part of this research will concentrate on the influence of organic exopolysaccharides (EPS) on Fe solubility and complexation (and hence bioavailability), both within the ice and in surrounding surface waters. This innovative research will improve our understanding of key processes that control the productivity of the climatically-important Antarctic sea-ice zone. Specifically, in this project: - The biogeochemical behaviour of Fe in sea-ice with regards to EPS complexation, and key physicochemical and biological data will be evaluated. - The bioavailability of Fe for phytoplankton growth during sea-ice melt will be investigated through laboratory-based experiments designed to mimic spring conditions. - The distribution of other bioactive trace elements in the Antarctic sea-ice environment will be examined as a means of fingerprinting the source(s) of Fe, as well as indicating their biological requirement. Taken from the 2008-2009 Progress Report: Progress against objectives: In the last twelve months we achieved all the objectives planned for the shore-based sample processing and analysis from the SIPEX voyage (fieldwork September-October 2007). An extensive and unique seasonal and spatial data set was put together including parameters such as ice texture, salinity, temperature, Chlorophyll a, particulate organic carbon (POC), dissolved organic carbon (DOC), macro-nutrients (silicate, phosphate and nitrate), and exoplysaccharides (EPS, using both alcian blue and PSA methods). Dissolved iron (dFe) and total dissolvable iron (TDFe) were analysed by flow injection - chemiluminescence (FIA-CL) analysis in Hobart. Polycarbonate (PC) filters (Nuclepore 0.2 micron pore size) retaining particulate metals were digested in a mixture of strong, ultrapure acids (750 micro litre 12N HCl, 250 micro litre 40% HF, 250 micro litre 14N HNO3) on a hotplate at 125 degrees C for 8 h. The procedure was successfully applied to plankton, estuarine and river sediment reference materials to verify the recovery of the digestion treatment. The concentrations of particulate iron (PFe) were determined by high resolution ICP-MS at the Central Science Laboratory at UTAS. This data has been quality-controlled, analysed, interpreted and published (see below). Due to the fact that logistical support was not possible for 2008/09 (insufficient berths at Casey Station) despite approval of our project, the field component of the project was delayed. Taken from the 2009-2010 Progress Report: Progress against objectives: Monthly Milestones of PhD student Pier van der Merwe: Successful Antarctic research expedition occurred in Oct-Dec 2009 at Casey Station Antarctica with logistical support from AAS project #3026 (flight on FA02 and berths at Casey station as well as field support of personnel). OCT-DEC 2009 - Antarctic time series data collection and processing successful. Data analysis scheduled for Jan - Mar. Write up of last paper(s) scheduled for Mar-June. Final completion of thesis due in August. DEC - Chlorophyll a data analysed JAN - FIA and CLECSV analyses start simultaneously FEB - Finish FIA analyses and attend Ocean science meeting in Portland Oregon. MAR - Finish CLECSV analyses and run POC and PFe digestions and analyses. Scheduled with Thomas Rodemann and Ashley Townsend at the CSL, UTAS. APR - MAY Data analysis and write up of 3rd paper, and possibly 4th based on field work at Casey station Oct-Dec 2009. See the child metadata records for more information about the data.