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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 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 (down) refbase @ user @ Serial 12985  
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Author Raike, A.; Kortelainen, P.; Mattsson, T.; Thomas, D.N. url  doi
openurl 
  Title 36 year trends in dissolved organic carbon export from Finnish rivers to the Baltic Sea Type Journal Article
  Year 2012 Publication The Science of the Total Environment Abbreviated Journal Sci Total Environ  
  Volume 435-436 Issue Pages 188-201  
  Keywords Baltic States; Carbon/*chemistry; Finland; Hydrology; Oceans and Seas; Rivers/*chemistry; Seasons; Soil/chemistry  
  Abstract Increasing dissolved organic carbon (DOC) concentrations in lakes, rivers and streams in northern mid latitudes have been widely reported during the last two decades, but relatively few studies have dealt with trends in DOC export. We studied the export of DOC from Finnish rivers to the Baltic Sea between 1975 and 2010, and estimated trends in DOC fluxes (both flow normalised and non-normalised). The study encompassed the whole Finnish Baltic Sea catchment area (301,000 km(2)) covering major land use patterns in the boreal zone. Finnish rivers exported annually over 900,000 t DOC to the Baltic Sea, and the mean area specific export was 3.5 t km(-2). The highest export (7.3t km(-2)) was measured in peat dominated catchments, whereas catchments rich in lakes had the lowest export (2.2 t km(-2)). Inter-annual variation in DOC export was high and controlled mainly by hydrology. There was no overall trend in the annual water flow, although winter flow increased in northern Finland over 36 years. Despite the numerous studies showing increases in DOC concentrations in streams and rivers in the northern hemisphere, we could not find any evidence of increases in DOC export to the northern Baltic Sea from Finnish catchments since 1975.  
  Address Finnish Environment Institute (SYKE), P.O. Box 140, FI-00251, Helsinki, Finland. antti.raike@ymparisto.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 0048-9697 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:22854090 Approved no  
  Call Number (down) refbase @ user @ Serial 12986  
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Author Lakaniemi, A.-M.; Hulatt, C.J.; Wakeman, K.D.; Thomas, D.N.; Puhakka, J.A. url  doi
openurl 
  Title Eukaryotic and prokaryotic microbial communities during microalgal biomass production Type Journal Article
  Year 2012 Publication Bioresource Technology Abbreviated Journal Bioresour Technol  
  Volume 124 Issue Pages 387-393  
  Keywords Bacteria/classification/genetics/metabolism; *Biomass; Electrophoresis, Polyacrylamide Gel; Eukaryotic Cells; Microalgae/*metabolism; Phylogeny; Polymerase Chain Reaction; Prokaryotic Cells  
  Abstract Eukaryotic and bacterial communities were characterized and quantified in microalgal photobioreactor cultures of freshwater Chlorella vulgaris and marine Dunaliella tertiolecta. The microalgae exhibited good growth, whilst both cultures contained diverse bacterial communities. Both cultures included Proteobacteria and Bacteroidetes, while C. vulgaris cultures also contained Actinobacteria. The bacterial genera present in the cultures were different due to different growth medium salinities and possibly different extracellular products. Bacterial community profiles were relatively stable in D. tertiolecta cultures but not in C. vulgaris cultures likely due to presence of ciliates (Colpoda sp.) in the latter. The presence of ciliates did not, however, cause decrease in total number of C. vulgaris or bacteria during 14 days of cultivation. Quantitative PCR (qPCR) reliably showed relative microalgal and bacterial cell numbers in the batch cultures with stable microbial communities, but was not effective when bacterial communities varied. Raw culture samples were successfully used as qPCR templates.  
  Address Department of Chemistry and Bioengineering, Tampere University of Technology, 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 0960-8524 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:22995170 Approved no  
  Call Number (down) refbase @ user @ Serial 12987  
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Author Underwood, G.J.C.; Aslam, S.N.; Michel, C.; Niemi, A.; Norman, L.; Meiners, K.M.; Laybourn-Parry, J.; Paterson, H.; Thomas, D.N. url  doi
openurl 
  Title Broad-scale predictability of carbohydrates and exopolymers in Antarctic and Arctic sea ice Type Journal Article
  Year 2013 Publication Proceedings of the National Academy of Sciences of the United States of America Abbreviated Journal Proc Natl Acad Sci U S A  
  Volume 110 Issue 39 Pages 15734-15739  
  Keywords Antarctic Regions; Arctic Regions; Biopolymers/*analysis; Carbohydrates/*analysis; Ice Cover/*chemistry; Models, Chemical; Molecular Weight; Solubility; algae; biogeochemistry; global relationships; microbial  
  Abstract Sea ice can contain high concentrations of dissolved organic carbon (DOC), much of which is carbohydrate-rich extracellular polymeric substances (EPS) produced by microalgae and bacteria inhabiting the ice. Here we report the concentrations of dissolved carbohydrates (dCHO) and dissolved EPS (dEPS) in relation to algal standing stock [estimated by chlorophyll (Chl) a concentrations] in sea ice from six locations in the Southern and Arctic Oceans. Concentrations varied substantially within and between sampling sites, reflecting local ice conditions and biological content. However, combining all data revealed robust statistical relationships between dCHO concentrations and the concentrations of different dEPS fractions, Chl a, and DOC. These relationships were true for whole ice cores, bottom ice (biomass rich) sections, and colder surface ice. The distribution of dEPS was strongly correlated to algal biomass, with the highest concentrations of both dEPS and non-EPS carbohydrates in the bottom horizons of the ice. Complex EPS was more prevalent in colder surface sea ice horizons. Predictive models (validated against independent data) were derived to enable the estimation of dCHO concentrations from data on ice thickness, salinity, and vertical position in core. When Chl a data were included a higher level of prediction was obtained. The consistent patterns reflected in these relationships provide a strong basis for including estimates of regional and seasonal carbohydrate and dEPS carbon budgets in coupled physical-biogeochemical models, across different types of sea ice from both polar regions.  
  Address School of Biological Sciences, University of Essex, Colchester, Essex CO4 3SQ, United Kingdom  
  Corporate Author Thesis  
  Publisher National Academy of Sciences Place of Publication Washington, DC Editor  
  Language English Summary Language English Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0027-8424 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:24019487; PMCID:PMC3785782 Approved no  
  Call Number (down) refbase @ user @ Serial 17491  
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Author Weykam, G.; Thomas, D.N.; Wiencke, C. openurl 
  Title Growth and photosynthesis of the Antarctic red algae Palmaria decipiens (Palmariales) and Iridaea cordata (Gigartinales) during and following extended periods of darkness Type Journal Article
  Year 1997 Publication Phycologia Abbreviated Journal Phycologia  
  Volume 36 Issue 5 Pages 395-405  
  Keywords Winter; Polar waters; Photosynthesis; Antarctic zone; Ice cover; Seaweeds; Light effects; Plant physiology; Growth; Palmariales; Gigartinales; Iridaea cordata; Palmaria decipiens; Ps; Antarctica  
  Abstract Physiological and developmental responses during and following long-term exposure to darkness were investigated in the Antarctic red algae Palmaria decipiens and Iridaea cordata. Thalli were kept in darkness for a period of 6 mo, simulating winter sea ice cover. Subsequently, they were grown illuminated under seasonally fluctuating Antarctic daylengths. During darkness, P. decipiens, an Antarctic endemic, rapidly lost its ability to photosynthesize although chlorophyll a content remained fairly constant. The amount of floridean starch decreased gradually in the dark, with a sudden drop simultaneous with the development of new blades. After reexposure to light there was a rapid increase in photosynthetic oxygen production, whereas the rate of carbon assimilation increased more slowly, resulting in high apparent photosynthetic quotients. The increase in growth rate showed a close relation to carbon assimilation, suggesting that carbon is utilized first for growth, then for floridean starch accumulation. In contrast to P. decipiens, the photosynthetic rate of the Antarctic cold-temperate I. cordata was still about half of the initial rate after a dark period of 6 mo, i.e. the alga maintained functionality of its photosynthetic apparatus during winter. After reexposure to light there was a continuous increase in specific growth rate due to increasing photosynthetic activity. Iridaea cordata also accumulated floridean starch during summer, although in smaller amounts than P. decipiens. Together with the ability to photosynthesize, starch accumulation facilitates survival during extended dark periods in winter. The early development of blade initials and the rapid increase in photosynthetic capability after illumination may permit P. decipiens to use the period of high water transparency optimally in Antarctic spring. Iridaea cordata seems better able to survive prolonged dark periods in areas with less predictable light conditions. Both physiological patterns are well suited to the highly seasonal light conditions in Antarctica.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0031-8884 ISBN Medium  
  Area Expedition Conference  
  Notes Marine Approved no  
  Call Number (down) refbase @ admin @ Weykam++1997 Serial 767  
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