Tag: DNA

Reports

Biodiversity in hot springs at Þeistareykir and Gjástykki / Biodiversity in hot springs at Þeistareykir and Gjástykki

Published:

01/12/2008

Authors:

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

Supported by:

Þeistareykir ehf

Contact

Guðmundur Óli Hreggviðsson

Strategic Scientist

gudmundo@matis.is

Biodiversity in hot springs at Þeistareykir and Gjástykki / Biodiversity in hot springs at Þeistareykir and Gjástykki

The project was part of an environmental assessment for the planned geothermal utilization and involved a study of the ecosystem in the hot springs at Þeistareykir and Gjástykki. A total of 27 samples were taken. Temperatures and acidity at the sampling points ranged from 33-96 ° C to pH 1.9-8.6. The species composition of the micro-organisms and their proportions were determined by nucleic acid amplification and sequencing of the 16S rRNA species-determining gene using bacterial and antimicrobial markers. A total of 21 bacteria and / or ancient bacteria were detected in 21 samples. DNA sequences were classified into species according to 98% affinities and compared with Genbank sequences for species analysis. In acidic hot springs at Þeistareykir, species within the bacterial assemblages β-, δ-, and γ-Proteobacteria and Aquificae were most common, especially acidic and / or primitive species that use sulfur and iron compounds and bind CO2. In vapors in lava caves at Þeistareykir at higher acidity levels (pH 6.7-8.6), the species Acidobacteria, Actinobacteria, Chloroflexi and Deinococcus-Thermus were prominent. Deinococcus-Thermus and Verrucomicrobium were the most common in samples from the hot springs in Gjástykki (pH 4.4-6.9). Many of these species are non-primitive. Ancient bacteria were found mainly in acidic areas at Þeistareykir, and in all samples from Gjástykki, but not in steam eyes in lava at Þeistareykir, as the acidity level is higher there. Species within the Crenarchaeota group were found in all of these samples, but species within the Euryarchaeota were bound to samples from the surface formations and acid soils. Most ancient bacteria can live primitive life. Biodiversity (Nt / Nmax) bacteria was most often between 1-3 and 1-2 among ancient bacteria. These low values are typical of peripheral ecosystems, where one species is in a very high proportion. Numerous new species were found in the samples, especially bacteria in steam eyes in lava at Þeistareykir and in hot springs in Gjástykki. Also, species of Euryarchaeota within ancient bacteria often showed a low kinship percentage and are therefore considered new species.

Due to future plans for utilizing the geothermal power at Þeistareykir and Gjástykki, an environmental assessment of the biodiversity in hot springs from these sites was carried out. A total of 27 samples were taken from various sites at temperatures of 33-96 ° C and pH 1.9-8.6. The species composition and ratios of thermophiles were estimated by PCR and sequencing of the 16S rRNA genes using bacterial and archaeal primers. Microbial species were detected in 21 samples. DNA sequences were grouped at the 98% similarity species level and compared with available sequences in Genbank for species determination. Species belonging to the bacterial phyla of β-, δ-, and γ-Proteobacteria and Aquificae were dominating in samples from the solfatara fields of Þeistareykir. These were mainly acidophiles and autotrophs capable of utilizing sulfur- and iron compounds and fixing CO2. A totally different pattern of species composition was observed in samples from fumaroles at the lava fields of Þeistareykir at higher pH (6,7-8,6) than in the solfataras. These were mainly Acidobacteria, Actinobacteria, Chloroflexi and DeinococcusThermus. In Gjástykki, (pH 4.4-6.9) Deinococcus-Thermus and Verrucomicrobium sp. were dominating. These are mainly heterotrophs. Archeal species were found as well in the solfatara fields at Þeistareykir and also in hot springs at Gjástykki, but not in the high pH fumaroles at Þeistareykir lava fields. Species from the Crenarchaeota group were found in the samples, but species belonging to the Euryarchaeota group were only detected in solfatara soil samples and sulfur / iron precipitates. These were mainly autotrophs. Biodiversity (Nt / Nmax) was calculated for all samples and estimated at 1-3 among the Bacteria and 1-2 among the Archaea. These low values are typical for extreme environments where one species is highly dominating. Many novel species were found in the samples, especially in soil from fumaroles at the lava field at Þeistareykir and in hot springs at Gjástykki. Euryarchaeal species within the Archaea domain often showed low similarity to known species and most likely represent new species.

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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.

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