The Red Layer Microbial Observatory—a Research Experience for Undergraduates in Yellowstone

  • This title combines two official grant titles this project has encompassed: 2000-2002 "Undergraduate Research in the Molecular Diversity of Hot Spring Bacteria"; and 2003-7 "A Longitudinal Molecular Diversity and Chemical Survey of Red Layer Microbial Communities in Yellowstone."

Created by George Rice, Montana State University

Two researchers surveying a thermal area with mat community.

Extreme temperature [45-60°C] microbial communities such as those thriving in hot springs in Yellowstone National Park are hypothesized to be modern analogues to the most ancient forms of life on earth. Evidence of stromatolites resembling modern mats exists from at least 3.6 billion years ago [Schopf and Packer, 1987]. Petrographic thin sections from stromatolites reveal filamentous bacteria resembling extant phototrophic species such as cyanobacteria and Chloroflexus [Walter, 1983]. Micropaleontologists consequently hypothesize that ancient bacteria were also phototrophic [Walter, 1983]. Current research of thermal mat systems, therefore, inquires to discover and identify new filamentous mat-forming bacteria that may be relatives of the most ancient forms of life on earth.

Yellowstone National Park: 3 RLMO sites being monitored long-term, 20 RLMO sites surveyed/archived click for RLMO Site Data Base

Map of RLMO sites in Yellowstone
Map of Yellowstone with RLMO sites.
Site image of Bechler Ferris 1

Bechler-Ferris 1 survey site

This remote thermal basin, one of the southernmost along the Yellowstone caldera, requires 2-3 days of backpacking to access. This impressive mat was one of many similar features up the Ferris Fork drainage, accessed from Three Forks.

image of students sampling at Fairy thermal site

Fairy survey site

Fairy Geyser has been a consistently active spouter that supports an extensive mat with a variable red layer community. Fairy springs are significantly off-trail.


image of microbial mat core

Modern mat communities are often composed of two types of organisms that form distinct laminations. The top layer of these mat systems is generally composed of oxygenic, photoautotrophic cyanobacteria. Beneath this lies a layer of anoxygenic, photoheterotrophic Chloroflexus [Castenholz, 1984]. Incident light striking the mat surface is filtered through the mat such that the quality of light penetrating each layer of the mat differs. At each layer, the phototrophic organisms consume those wavelengths absorbed by their pigment-protein complexes. In this way, the light-absorbing properties of the bacteria within the layers of the mat are believed to correlate with their positions in the mat [Castenholz, 1984].

Copyright on all images and material by Sarah Boomer 1998-2005.

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