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Microbial sulfur transformations in sediments from Subglacial Lake Whillans
Alicia M Purcell1, Jill A Mikucki1, Amanda M Achberger2
1Department of Microbiology, University of Tennessee Knoxville, TN, USA.
Frontiers in Microbiology
|December 6, 2014
Summary
Microbes in Antarctica's Subglacial Lake Whillans transform sulfur compounds. Genes indicate both sulfur oxidation and reduction, with sulfur oxidizers dominating surface sediments, impacting ocean chemistry.
Area of Science:
- Microbiology
- Geochemistry
- Antarctic Science
Background:
- Subglacial aquatic environments harbor diverse microbial communities.
- These microbes utilize reduced minerals like sulfur for energy.
- Understanding sulfur cycling is key to subglacial ecosystem function.
Purpose of the Study:
- Investigate microbially mediated sulfur transformations in Subglacial Lake Whillans (SLW) sediments.
- Analyze key genes involved in dissimilatory sulfur oxidation and reduction.
- Determine the genetic potential and activity of sulfur cycling microbes in SLW.
Main Methods:
- Gene analysis of adenosine-5 omino-phosphosulfate (APS) reductase, reverse-acting dissimilatory sulfite reductase (rDSR), and 16S rRNA.
- Depth profiling of gene presence and abundance in SLW sediments.
- Experimental measurement of sulfate reduction rates.
Main Results:
- Sulfur transformation genes showed depth-dependent variation in SLW sediments.
- Surficial sediments were rich in genes for sulfur-oxidizing chemoautotrophs, particularly "Sideroxydans" and Thiobacillus.
- Genetic potential for sulfate reduction was confirmed by low measured rates and specific gene sequences, alongside evidence for sulfur oxidation.
Conclusions:
- SLW sediments host microbial communities with the genetic capacity for both sulfur oxidation and reduction.
- Sulfur oxidation appears to be a significant energy source for chemosynthesis in SLW.
- Subglacial sulfur transformations can influence solute flux to the Southern Ocean.
Keywords:
Antarctic subglacial aquatic environmentschemosynthesisgeomicrobiologysulfate reductionsulfur oxidationMore Related Videos
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