Reports

Lífríki í kalkríkum hverum á Ölkelduháls / Microbial ecology of calcium rich hot springs at Ölkelduháls geothermal area

Published:

01/10/2008

Authors:

Sólveig K. Pétursdóttir, Snædís Björnsdóttir, Alexandra Klonowski, Sólveig Ólafsdóttir, Guðmundur Óli Hreggviðsson

Supported by:

The Environmental and Energy Research Fund of Orkuveita Reykjavíkur

Contact

Alexandra María Klonowski

Project Manager

alex@matis.is

Lífríki í kalkríkum hverum á Ölkelduháls / Microbial ecology of calcium rich hot springs at Ölkelduháls geothermal area

The ecology of calcareous hot springs is little studied. This study involved analyzing the ecosystem in calcareous hot springs at Ölkelduháls and assessing whether it had a special position compared to the ecosystem of other hot springs in the same area with the same temperature and acidity. Bacteria were isolated from thermal samples by conventional culture methods. Genetic analysis methods were used to analyze the species composition. Many species found in samples from calcareous hot springs are also found in other hot springs. It is noteworthy, however, that species within the Aquificae party were not found in the samples, but they are very common in hot springs and widely prevalent. Elemental measurements showed differences in the concentration of sulfur, iron, carbon and arsenic in calcareous water and other hot springs, which may be an explanation for this. Cultivated methods identified mainly known bacterial species of the genera Thermus and Bacillus. One new species of the Meiothermus genus was isolated. Using genetic analysis methods, 195 true bacterial clones were obtained from calcareous hot springs, which were classified into 60 species based on 98% affinity. These 60 species are spread over nine camps. The species found in the samples were the same between the hot springs, but also unique to the sample from which they came. No ancient bacteria were found in the samples. Biodiversity in samples from calcareous hot springs at Ölkelduháls was slightly higher than comparable values from hot springs with similar properties in the same area. The high proportion of unknown species and genera in samples taken in calcareous hot springs at Ölkelduháls is noteworthy. Of the 60 species found in the samples, a sufficiently close relative of the same species was found in 25 cases. The other 35 species were so closely related to close relatives that they could not be classified except into genera, tribes, clans, or families. Ecosystems in calcareous hot springs at Ölkelduháls must therefore be considered very special.

The ecology of calcium rich hot springs is not well documented. In this study an attempt was made to estimate if microbial species composition in calcium rich hot springs in Ölkelduháls in Iceland was special compared to species composition in other hot springs with similar temperature and pH in the same geothermal area. Isolation methods as well as culture independent methods were used to analyze species composition in the samples. Many species found in the calcium rich hot springs are also found in other hot springs. It is noteworthy that Aquificae species were totally absent in samples from calcium rich hot springs, but these species were abundant and dominating in other hot spring samples. Elemental analysis of hot spring water revealed a difference in the concentration of sulfur, iron, carbon and arsenate between calcium rich hot springs and other hot springs in the area. Known species of Thermus and Bacillus genera were isolated from the samples. A novel Meiothermus species was isolated. Approximately 60 species belonging to nine phyla were identified in the samples using culture independent methods. The species identified in the calcium rich samples were identical between samples but also unique for the sample investigated. No archaea were detected in the samples. Biodiversity calculated for the samples from calcium rich hot springs was slightly higher than in samples from other hot springs. A high ratio of unknown species and genera in the samples from calcium rich hot springs in Ölkelduháls is remarkable. Of the total of 60 species identified only 25 had a close relative from the same species according to Genbank. The remaining 35 species were only distantly related to their closest relative and could only be classified to genera, families, orders or classes. Thus, the ecology of calcium rich hot springs appears to be quite unique.

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