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Author Steffens, M.; Granskog, M.A.; Kaartokallio, H.; Kuosa, H.; Luodekari, K.; Papadimitriou, S.; Thomas, D.N. openurl 
  Title Spatial variation of biogeochemical properties of landfast sea ice in the Gulf of Bothnia, Baltic Sea Type Conference Article
  Year 2006 Publication Proceedings of the International Symposium on Sea Ice, Dunedin (New Zealand), 5-9 Dec 2005 Abbreviated Journal  
  Volume Issue Pages (down) 80-87  
  Keywords  
  Abstract  
  Address  
  Corporate Author Thesis  
  Publisher International Glaciological Society Place of Publication Cambridge Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Annals of Glaciology Abbreviated Series Title  
  Series Volume 44 Series Issue Edition  
  ISSN ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number refbase @ admin @ Steffens2006 Serial 17396  
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Author Steffens, M.; Granskog, M.A.; Kaartokallio, H.; Kuosa, H.; Luodekari, K.; Papadimitriou, S.; Thomas, D.N. openurl 
  Title Spatial variation of biogeochemical properties of landfast sea ice in the Gulf of Bothnia, Baltic Sea Type Conference Article
  Year 2006 Publication Proceedings of the International Symposium on Sea Ice, Dunedin (New Zealand), 5-9 Dec 2005 Abbreviated Journal  
  Volume Issue Pages (down) 80-87  
  Keywords  
  Abstract  
  Address  
  Corporate Author Thesis  
  Publisher International Glaciological Society Place of Publication Cambridge Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Annals of Glaciology Abbreviated Series Title  
  Series Volume 44 Series Issue Edition  
  ISSN ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number refbase @ admin @ Steffens2006 Serial 17407  
Permanent link to this record
 

 
Author Lakaniemi, A.-M.; Hulatt, C.J.; Thomas, D.N.; Tuovinen, O.H.; Puhakka, J.A. url  doi
openurl 
  Title Biogenic hydrogen and methane production from Chlorella vulgaris and Dunaliella tertiolecta biomass Type Journal Article
  Year 2011 Publication Biotechnology for Biofuels Abbreviated Journal Biotechnol Biofuels  
  Volume 4 Issue 1 Pages (down) 34  
  Keywords  
  Abstract BACKGROUND: Microalgae are a promising feedstock for biofuel and bioenergy production due to their high photosynthetic efficiencies, high growth rates and no need for external organic carbon supply. In this study, utilization of Chlorella vulgaris (a fresh water microalga) and Dunaliella tertiolecta (a marine microalga) biomass was tested as a feedstock for anaerobic H2 and CH4 production. RESULTS: Anaerobic serum bottle assays were conducted at 37 degrees C with enrichment cultures derived from municipal anaerobic digester sludge. Low levels of H2 were produced by anaerobic enrichment cultures, but H2 was subsequently consumed even in the presence of 2-bromoethanesulfonic acid, an inhibitor of methanogens. Without inoculation, algal biomass still produced H2 due to the activities of satellite bacteria associated with algal cultures. CH4 was produced from both types of biomass with anaerobic enrichments. Polymerase chain reaction-denaturing gradient gel electrophoresis profiling indicated the presence of H2-producing and H2-consuming bacteria in the anaerobic enrichment cultures and the presence of H2-producing bacteria among the satellite bacteria in both sources of algal biomass. CONCLUSIONS: H2 production by the satellite bacteria was comparable from D. tertiolecta (12.6 ml H2/g volatile solids (VS)) and from C. vulgaris (10.8 ml H2/g VS), whereas CH4 production was significantly higher from C. vulgaris (286 ml/g VS) than from D. tertiolecta (24 ml/g VS). The high salinity of the D. tertiolecta slurry, prohibitive to methanogens, was the probable reason for lower CH4 production.  
  Address Department of Chemistry and Bioengineering, Tampere University of Technology, PO Box 541, FI-33101 Tampere, Finland. aino-maija.lakaniemi@tut.fi  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1754-6834 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:21943287; PMCID:PMC3193024 Approved no  
  Call Number refbase @ user @ Serial 12985  
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Author Thomas, D.N.; Mock, T. url  openurl
  Title Life in frozen veins – coping with the cold Type Journal Article
  Year 2005 Publication The Biochemist Abbreviated Journal Biochemist  
  Volume 27 Issue 1 Pages (down) 12-16  
  Keywords adaptation; Antarctic; Arctic; low temperature; micro-organism; sea ice  
  Abstract Every autumn a fundamental transition occurs in the surface waters of Polar Oceans. The surface waters of millions of square kilometres freeze to form an ice layer that varies from a few centimetres through to several metres thick, and which effectively separates the ocean from the atmosphere above. Ice made from seawater is a porous, semi-solid matrix permeated by a labyrinth of brine channels and pores, and within these a diverse microbial assemblage, including viruses, archaea, bacteria, flagellates and unicellular algae can thrive. These assemblages can reach such high abundances that the ice becomes a rich coffee colour. The microbial assemblages are in turn a rich food source for grazing proto- and zooplankton, especially in winter when food in the water column is scarce.  
  Address  
  Corporate Author Thesis  
  Publisher Biochemical Society Place of Publication London Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number refbase @ admin @ Thomas+Mock2005 Serial 765  
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Author Kattner, G.; Thomas, D.N.; Haas, C.; Kennedy, H.; Dieckmann, G.S. url  openurl
  Title Surface ice and gap layers in Antarctic sea ice: highly productive habitats Type Journal Article
  Year 2004 Publication Marine Ecology Progress Series Abbreviated Journal Mar Ecol Prog Ser  
  Volume 277 Issue Pages (down) 1-12  
  Keywords Antarctic sea ice; Gap layers; Biogeochemistry; Particulate organic matter; Dissolved organic matter; Chlorophyll a; Nutrients  
  Abstract Biogeochemical investigations of the upper layers of sea ice were made on layered summer ice floes collected from the Weddell Sea, Antarctica, from mid-February to March 1997. The surface layers had a clearly defined bottom layer immediately overlying a gap filled with seawater. Generally the gap covered rotten sea ice below. Using differences in algal biomass, mostly in the bottom layer of the surface ice overlying the gap, the floes were classified as low, moderate or high biomass. In addition, a floe with a re-frozen gap layer was studied. In the floes with the highest biomass, particulate organic carbon (POC) and nitrogen (PON) reached concentrations of up to 6000 µMC and 600 µMN in the bottom layer. In the upper part of the surface ice layer and the gap water, particulate and dissolved organic matter concentrations (POM, DOM) were clearly lower. High concentrations of POM were generally accompanied by high values of DOM although POM values generally exceeded DOM. All C and N contents of organic matter were significantly correlated. In gap waters, POM was low but still clearly higher than in the surrounding seawater, whereas DOM was in the range of seawater concentrations. Most POC/PON and C/chlorophyll a ratios pointed to an actively growing algae community, whereas the higher and more variable DOC/DON ratios reflected the various sources influencing DOM composition. Nitrate and silicate closely followed the signature of salinity, reaching in some gap water samples values similar to seawater concentrations. In some samples, in particular from the upper part of the surface ice layer, nitrate was totally exhausted. The distribution of the regenerated nutrients ammonium and phosphate was totally different from that of nitrate and silicate, reaching values of up to 15.9 and 9.08 µM, respectively. The bottom ice layer of the floe with the re-frozen gap layer had a high biomass similar to that of the high-biomass ice floe. DOC concentrations were lower, and DON maximum was not clearly linked with DOC maximum, but instead was associated with high ammonium and phosphate concentrations. The significant correlations between POM and DOM as well as between nitrate and silicate and between the regenerated nutrients ammonium and phosphate indicate that the gap-layer floes are semi-enclosed, highly productive habitats that still maintain high biomass during freezing. They are ubiquitous in the Antarctic pack-ice zone and important features that support high algae standing stocks.  
  Address  
  Corporate Author Thesis  
  Publisher Inter-Research Place of Publication Oldendorf/Luhe Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0171-8630 ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number refbase @ admin @ Kattner++2004 Serial 745  
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