| |
Records |
Links |
|
Author  |
Lakaniemi, A.-M.; Hulatt, C.J.; Thomas, D.N.; Tuovinen, O.H.; Puhakka, J.A. |
|
| |
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 |
refbase @ user @ |
Serial |
12985 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Lakaniemi, A.-M.; Hulatt, C.J.; Wakeman, K.D.; Thomas, D.N.; Puhakka, J.A. |
|
| |
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 |
refbase @ user @ |
Serial |
12987 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Mock, T.; Dieckmann, G.S.; Haas, C.; Krell, A.; Tison, J.-L.; Belem, A.L.; Papadimitriou, S.; Thomas, D.N. |
|
| |
Title |
Micro-optodes in sea ice: a new approach to investigate oxygen dynamics during sea ice formation |
Type |
Journal Article |
| |
Year |
2002 |
Publication |
Aquatic Microbial Ecology |
Abbreviated Journal |
Aquat Microb Ecol |
|
| |
Volume |
29 |
Issue |
3 |
Pages |
297-306 |
|
| |
Keywords |
Fragilariopsis cylindrus; Oxygen; Methods; Micro-optodes; Sea ice; Biogeochemistry; Diatoms; Algae; Chlorophyll; Photosynthesis; Salinity effects; Sea water; Marine ecosystems; Chlorophylls; Dissolved oxygen; Gases; Epontic environment; Electrodes; Sensors; Brines; Ice-water interface; Ice formation; Bacillariophyceae |
|
| |
Abstract |
Oxygen micro-optodes were used to measure oxygen dynamics directly within the microstructure of sea ice by freezing the sensors into the ice during its formation. The experiment was conducted in a 4 m³ mesocosm filled with artificial seawater and inoculated with a unialgal culture of the common Antarctic ice diatom Fragilariopsis cylindrus (Bacillariophyceae) to a final chlorophyll a (chl a) concentration of 11 µg 1?¹. Ice growth was initiated 7 d after inoculation by reducing the air temperature to -10 plus or minus 2 degree C and terminated 17 d later. The final ice thickness was 27 cm. One optode was frozen into grease ice and 2 others into the skeletal layer of the growing ice sheet. Increasing oxygen concentrations during ice crystal formation at the water surface and the ice-water interface revealed a strong inclusion of oxygen, which was either physically trapped and/or the result of photosynthesising diatoms. The major portion of oxygen was present as gas bubbles due to super-saturation as a result of increasing salinity and oxygen production by diatoms. An increase in salinity due to a concurrent decrease in ice temperatures during subsequent sea ice development reduced the maximum concentration of dissolved oxygen within brine. Thus, dissolved oxygen concentrations decreased over time, whereas gaseous oxygen was released to the atmosphere and seawater. The sensors are a significant advance on more conventional microelectrodes, because the recordings can be temperature and salinity compensated in order to obtain precise measurements of oxygen dynamics with regard to total (dissolved and gaseous) and dissolved oxygen in sea ice. Optodes do not consume oxygen during measuremnet over a long period under extreme conditions, which is another advantage for long-term deployment in the field. |
|
| |
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 |
0948-3055 |
ISBN |
|
Medium |
|
|
| |
Area |
|
Expedition |
|
Conference |
|
|
| |
Notes |
Marine |
Approved |
no |
|
| |
Call Number |
refbase @ admin @ Mock++2002 |
Serial |
749 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Mock, T.; Thomas, D.N. |
|
| |
Title |
Recent advances in sea-ice microbiology |
Type |
Journal Article |
| |
Year |
2005 |
Publication |
Environmental Microbiology |
Abbreviated Journal |
Environ Microbiol |
|
| |
Volume |
7 |
Issue |
5 |
Pages |
605-619 |
|
| |
Keywords |
|
|
| |
Abstract |
Over the past 50 years there has been much effort invested in the investigation of the ecology of sea ice. Sea ice is an ephemeral feature of the Arctic and Southern Oceans and smaller water bodies such as the Baltic and Caspian Seas. The semisolid ice matrix provides a range of habitats in which a diverse range of microbial organisms thrive. In the past 5 years there has been considerable steps forward in sea-ice research, in particular regarding the analysis of sea-ice microstructure and the investigation of the diversity and adaptation of microbial communities. These studies include: (i) controlled simulated and in situ studies on a micrometer scale to unravel the dynamic of the microhabitat with consequences for the organisms; (ii) the introduction of molecular approaches to uncover the diversity of uncultured still unknown microorganisms; and (iii) studies into the molecular adaptation of selected model organisms to the extreme environment. This minireview presents some of the most recent findings from sea-ice studies within the framework of these aims. |
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
Blackwell Publishing, Inc. |
Place of Publication |
Oxford |
Editor |
|
|
| |
Language |
|
Summary Language |
|
Original Title |
|
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
1462-2912 |
ISBN |
|
Medium |
|
|
| |
Area |
|
Expedition |
|
Conference |
|
|
| |
Notes |
Minireview |
Approved |
no |
|
| |
Call Number |
refbase @ admin @ Mock+Thomas2005 |
Serial |
750 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Raike, A.; Kortelainen, P.; Mattsson, T.; Thomas, D.N. |
|
| |
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 |
refbase @ user @ |
Serial |
12986 |
|
| Permanent link to this record |
