Diversity and distribution of sulfate-reducing bacteria in the permanently frozen Lake Fryxell, McMurdo Dry Valleys

• Main Authors: Elizabeth A. Karr, W. Matthew Sattley, Melissa R. Rice, Deborah O. Jung, Michael T. Madigan, Laurie A. Achenbach
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Published: 2005
• Subjects: Frozen Lake; Fryxell; Lake Fryxell; McMurdo Dry Valleys; Antarc*; Antarctica
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.598.7035; http://mcm-dvlakesmo.montana.edu/images/Data/publications/KarrEtAl2006Diversity.pdf

geochemistry for microbial sulfate reduction. To investigate the population of sulfate-reducing bacteria in Lake Fryxell, both 16S rRNA gene and metabolic primer sets targeting the dsrA gene for the dissimilatory sulfite reductase alpha subunit were employed to analyze environmental DNA obtained from the water column and sediments of Lake Fryxell. In addition, enrichment cultures of sulfate-reducing bacteria established at 4°C from Lake Fryxell water were also screened using the dsrA primer set. The sequence information obtained showed that a diverse group of sulfate-reducing prokaryotes of the domain Bacteria inhabit Lake Fryxell. With one exception, the enrichment culture sequences were not represented within the environmental sequences. Sequence data were compared with the geochemical profile of Lake Fryxell to identify possible connections between the diversity of sulfate-reducing bacteria and limnological conditions. Several clone groups were highly localized with respect to lake depth and, therefore, experienced specific physiochemical conditions. However, all sulfate-reducing bacteria inhabiting Lake Fryxell must function under the constantly cold conditions characteristic of this extreme environment. Lake Fryxell is a permanently ice-covered lake located in the McMurdo Dry Valleys, Antarctica. A perennial ice cover of 4 to 6 m and a small influx of glacial meltwater impose a stable