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Published on: April 20, 2012
Microbial diversity under extreme euxinia: Mahoney Lake, Canada.
V Klepac-Ceraj1, C A Hayes, W P Gilhooly
1Department of Molecular Genetics, Forsyth Institute, Cambridge, MA, USA. vanjakle@gmail.com
Geobiology
|February 15, 2012
Summary
Microbial diversity in Mahoney Lake is highest in the hypolimnion and sediments, not the purple sulfur bacteria plate. This suggests distinct microbial niches and sulfur cycling processes in this stratified saline lake.
Area of Science:
- Microbial ecology
- Limnology
- Biogeochemistry
Background:
- Mahoney Lake is a stratified saline lake with a euxinic hypolimnion.
- A dense plate of purple sulfur bacteria exists at the chemocline.
- The microbial ecosystem below the chemocline and in sediments remains largely unknown.
Purpose of the Study:
- To profile microbial community distributions in Mahoney Lake.
- To investigate microbial life in the aphotic hypolimnion and sediments.
- To understand the habitat of sulfate-reducing bacteria.
Main Methods:
- 16S rRNA gene clone libraries were used for microbial profiling.
- PhyloChip microarrays were employed to analyze microbial communities.
- Gene sequencing and microarray analysis provided insights into microbial diversity.
Main Results:
- Microbial diversity was greatest in the hypolimnion (8 m) and sediments.
- Diversity was lowest within the photosynthetic purple sulfur bacteria plate (7 m).
- Distinct microbial communities were found at different depths, with specific phyla dominating shallower or deeper zones.
Conclusions:
- Mahoney Lake harbors distinct microbial niches across its stratified depths.
- Sulfur cycle processes appear to be zoned within the lake's chemocline and hypolimnion.
- The findings contribute to understanding microbial ecosystems in stratified saline environments.
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