Tag: High temperature area

Reports

Biodiversity in hot springs in high-temperature areas in Iceland. Overall summary prepared for the Framework Program. Final report

Published:

01/12/2010

Authors:

Sólveig K. Pétursdóttir, Snædís H. Björnsdóttir, Guðmundur Óli Hreggviðsson, Sólveig Ólafsdóttir

Contact

Guðmundur Óli Hreggviðsson

Strategic Scientist

gudmundo@matis.is

Biodiversity in hot springs in high-temperature areas in Iceland. Overall summary prepared for the Framework Program. Final report

Research was carried out on the ecosystem in hot springs in five high-temperature areas in Iceland under the framework of the Framework Program in the years 2004-2009. The aim was to answer questions about the extent and nature of the variability in microbial flora between high-temperature areas in Iceland, which were studied mainly in terms of diversity and rare groups. This report summarizes the results obtained from the above studies. The areas that were examined were the Hengill area, Torfajökull area, Krafla / Námafjall, Krísuvík and Vonarskarð. Furthermore, the results of a similar study carried out for the environmental assessment of the geothermal areas at Þeistareykir and Gjástykki were included in this summary. A total of 115 samples were taken in the six areas and a species composition in 80 of them was analyzed. Species-identifying bacterial and archaeal bacteria in the DNA from the samples were amplified and sequenced. The sequences were classified by affinity and classified by species or genus by comparison with comparable sequences in Genbank. A total of 4424 bacterial sequences and 1006 ancient bacterial sequences were detected from the samples. The distribution of bacteria and ancient bacteria in the samples was examined and it was found that 16 bacterial assemblages were found in most areas and species of the Aquificae array were most common, as they are often primary producers in hot springs. Species of the β- and γ-proteobacterial and Deinococcus-Thermus factions were also found to a significant extent in all areas except Krísuvík. In addition, several other factions were found in individual areas. Within the ancient bacteria, Crenarcheota species were found in all areas, Euryarchaeota species were found in Vonarskarð and Þeistareykir, Thaumarchaeota was found in Vonarskarð and in Krafla / Námafjall and Nanoarchaeota in the Torfajökull area. Calculations of biodiversity (H) microorganisms in the six areas showed that the Krafla area was the most diverse, then Torfajökull, then Vonarskarð, Þeistareykir, Hengill and finally Krísuvík. The assessment of biodiversity by calculating the collection curves largely supported this conclusion. Biological specificity was assessed on the basis of rare species by ≤96% corresponding to close relatives in Genbank. A total of 74 rare species or genera were found in the samples and they seemed for the most part regional and it is not unlikely that some of them are endemic. Most new species or genera were found in the Torfajökull area. Vonarskarð, Krafla / Námafjall and Þeistareykir had slightly fewer rare species or genera. New tribes were also found in the Hengill area, but not to the same extent as in the former.

Culture independent methods were used to study the microbial composition of hot springs in five geothermal areas in Iceland in 2004-2009. The aim was to answer questions on the degree of biodiversity and to what extend the species found were unique to the sites investigated. In this report the site specific research results were combined and compared. The geothermal sites investigated were the Hengill area, the Torfajökull area, the Krafla / Námafjall area, Krísuvík and Vonarskarð. Results from a similar research from an environmental assessment of the geothermal areas of Þeistareykir and Gjástykki were also used. A total of 115 samples were collected from the six geothermal areas and the microbial species composition was estimated in 80 of them. The 16S rRNA genes were amplified from DNA from the samples and partially sequenced. The obtained sequences were classified and identified to the species or genus level by comparison to similar sequences in Genbank. The total of 4424 bacterial sequences and 1006 archaeal sequences were analyzed. The distribution of bacterial and archaeal phyla of the samples was investigated and revealed that 16 bacterial phyla were represented in all areas. Also, that the phylum of the primary producers of hot springs - Aquificae - was dominating. Species belonging to β‐ and γ ‐ proteobacteraa and Deinococcus - Thermus were also found in considerable amounts in all areas except Krísuvík. Several bacterial phyla were only found at one or two geothermal areas. Species belonging to Crenarchaeota were found in all six areas, Euryarchaeota were found in Vonarskarð and Þeistareykir, Thaumarchaeota was found in Vonarskarð as well as in the Krafla / Námafjall area and Nanoarchaeota in the Torfajökull area. Calculation of the biodiversity index (H) of microbial species of the six geothermal areas revealed that the index for the Krafla / Námafjall area was highest, then Torfajökull, Vonarskarð, Þeistareykir, Hengill and finally Krísuvík. The estimate of biodiversity based on Rarefaction curves confirmed the results. The estimation of uniqueness of the areas was based on the number of novel species found using ≤96% similarity to closest relative in Genbank as the cutoff value. The total of 74 novel species or genera were found in the samples most of which were only found in one or at most two areas. Most of these were from the Torfajökull area. A considerable number of novel species were also found in Vonarskarð, Námafjall and Þeistareykir. Novel species or genera were also found in the Hengill geothermal area.

View report

Reports

Biodiversity in hot springs in Krísuvík and Gunnuhver in Reykjanes: Research carried out due to the Framework Plan for the utilization of geothermal energy in high-temperature areas

Published:

01/08/2007

Authors:

Sólveig K. Pétursdóttir, Sólveig Ólafsdóttir, Steinunn Magnúsdóttir, Guðmundur Óli Hreggviðsson

Contact

Steinunn Ásbjörg Magnúsdóttir

Project Manager

steinunn.magnusdottir@matis.is

Biodiversity in hot springs in Krísuvík and Gunnuhver in Reykjanes: Research carried out due to the Framework Plan for the utilization of geothermal energy in high-temperature areas

This study of the ecosystem in the hot springs in the Krísuvík area is the third biota assessment carried out within the Framework Program, but the first two dealt with the ecosystem in the hot springs in the Hengill area and in the Torfajökull area.

Emphasis was placed on the thermal area in Seltún, where sampling was joint with the geochemists of the Institute of Earth Sciences, which was the first step in an interdisciplinary approach to the subject, which is hoped for, but is still in its early stages. Other areas that were tried to explore were hot springs by Austurengjahver and the area by Gunnuhver in Reykjanes. The temperature in the hot springs in Seltún was in the range of 53-93 ° C and furthermore one soil sample was reported which was taken at a lower temperature or 34 ° C. The acidity of the hot springs in Seltún was in the range of pH 2.5-6. The temperature in the hot springs at Austurengjahver was between 50-75 ° C and the pH pH 2.4 - 4.3. The temperature in the hot springs at Gunnuhver was measured in the range of 70-90 ° C and the pH pH 3.8 - 4.2. A total of thirteen samples were taken in the above areas and DNA was successfully isolated from seven of them. DNA could not be extracted from the samples at Austurengjahver. Nucleic acid amplification of the 16S rRNA, a species-differentiating gene of the nuclear nucleus, was performed on six samples. Amplification was obtained from all these samples with specific real bacterial indicators, but three with ancient bacterial indicators.

A total of 304 sequences of real bacterial species were obtained in the area known as Seltún. These species are spread over 26 species which in turn are spread over 10 camps. The primitive species of the Aquificeae array house over 80% sequences and are therefore predominant in these samples and are primary producers in the ecosystems of the hot springs. Five species within this array were found in the samples from Seltún. Other species are mainly classified into different groups Proteobacteria (13%) but they are a very diverse group. Other species found are sparsely populated and less important here. A total of 81 sequences of ancient bacterial species were obtained from the Seltún area. Most of them or space 90% are classified as Thermoplasmatales within the Euryarchaeota class, but this is a heat and acid species. Other ancient bacteria in the samples in Seltún belong to the Chrenarchaeota group, mostly to the genus Desulfurococcales.

A total of 56 actual bacterial differentiations were obtained from the hot springs at Gunnuhver. The vast majority of them (about 70%) belong to the primitive class Aquificeae, but about 30% to different groups of Proteobacteria. The ancient bacteria in Gunnuhver are homogeneous as they are all of the genus Sulfolobales which is a very heat and acid group. 1 Overall, it can be said that the area around Seltún shows a typical pattern of a peripheral ecosystem where one species is predominant and other species are spread over various factions. The calculated biodiversity in the samples was relatively low or in the range of 1.0-2.0. For comparison, the same coefficient calculated for samples from the Torfajökull area and at Ölkelduháls was in the range of 1.1-4.7. The environmental conditions of temperature and acidity in Seltún and Gunnuhver are not on the edge, but it is likely that substances and compounds in the hot springs and clay can affect the diversity of the ecosystem, ie. which species get thrive and which do not.

Rare species that had only distant relatives in Genbank were found in the Seltún samples, among others. In most cases, however, there are only 1-2 representatives of the species in question. Most of these distantly related species were classified as Proteobacteria and Acidobacteria.

Matís - Prokaria will probably continue to work on sampling and species analysis in the Krísuvík area. The intention is to include these results in a final summary of the ecosystem in hot springs in Iceland in the last year of the Framework Program.

View report
EN
IS EN