Microbial community composition and endolith colonization at an Arctic thermal spring are driven by calcite precipitation

• Published in: Environmental Microbiology Reports
• Main Authors: Starke, Verena, Kirshtein, Julie, Fogel, Marilyn L., Steele, Andrew
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 2013
• Subjects: Arctic
• Online Access: http://dx.doi.org/10.1111/1758-2229.12063; https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2F1758-2229.12063; http://onlinelibrary.wiley.com/wol1/doi/10.1111/1758-2229.12063/fullpdf

Summary Environmental conditions shape community composition. A rctic thermal springs provide an opportunity to study how environmental gradients can impose strong selective pressures on microbial communities and provide a continuum of niche opportunities. We use microscopic and molecular methods to conduct a survey of microbial community composition at T roll S prings on S valbard, N orway, in the high A rctic. Microorganisms there exist under a wide range of environmental conditions: in warm water as periphyton, in moist granular materials, and in cold, dry rock as endoliths. T roll S prings has two distinct ecosystems, aquatic and terrestrial, together in close proximity, with different underlying environmental factors shaping each microbial community. Periphyton are entrapped during precipitation of calcium carbonate from the spring's waters, providing microbial populations that serve as precursors for the development of endolithic communities. This process differs from most endolith colonization, in which the rock predates the communities that colonize it. Community composition is modulated as environmental conditions change within the springs. At T roll, the aquatic environments show a small number of dominant operational taxonomic units ( OTUs ) that are specific to each sample. The terrestrial environments show a more even distribution of OTUs common to multiple samples.