Geomicrobiology of the volcanic sulphur springs of St Lucia, West Indies (Past)

Dr. Lisa Stout former Postdoc in the laboratory of Dr. Ruth Blake usined molecular techniques to address questions in microbial ecology in geologically active environments. Dr. Stout’s research focused on the volcanic Sulphur Springs of St. Lucia, West Indies.  She studied how geochemical variations between hot spring pools may affect microbial diversity. In order to assess diversity of both domains bacteria and archaea at St. Lucia, she sequenced 16S ribosomal RNA (rRNA) genes, because they serve as a stable marker used to fingerprint different bacterial types.  Because many bacteria and archaea are as yet unculturable, this provides a more complete picture of microbial diversity. 
DNA was extracted from the total community, followed by Polymerase Chain Reaction (PCR) to amplify bacteria-specific and archaea-specific 16S rRNA genes. Genes from different species were separated by molecular cloning, and sequenced.  Dr. Stout also  worked with bacterial isolates from St. Lucia that are tolerant to high concentrations of boron. These isolates were also being characterized using DNA analysis including sequencing of the 16S rRNA gene.

Lastly, another project studies the phosphorous cycling in the environment via phosphate oxygen isotopic ratios.  In order to fully understand what PO4-water O isotope ratios tell us about the environment, we must calibrate this system over a range of conditions, such as temperature, pH, salinity, or nutrient concentrations that reflect the full range seen in the environment and in organisms.  Dr. Stout grew microorganisms that tolerate a wide range of conditions, from domains bacteria and archaea, including Escherichia coli, Marinobacter aquaeolei, Thermus aquaticus, and Sulfolobus acidocaldarius, as well as several environmental isolates, including those from St. Lucia and from Arctic sea ice.