Lechuguilla Cave

Microbiological Interactions of Microbial Communities in Cave Deep
Subsurface Environments: a Novel Extreme Environment

Geomicrobiological Team

Diana E. Northup Penelope J. Boston
University of New MexicoComplex Systems Research

Michael N. Spilde Clifford N. Dahm
University of New MexicoUniversity of New Mexico

Laura J. Crossey Susan M. Barns
University of New MexicoLos Alamos National Laboratories

Lawrence M. Mallory
Biomes, Inc.

Caves offer accessible subterranean environments in which to study the diversity of microbial life. These ecosystems are exposed to extreme environmental stresses and may be based on inorganic energy sources rather than sunlight. An excellent example of subterranean microbial life is found in Lechuguilla Cave (New Mexico), the deepest cave in the continental United States. Lechuguilla Cave, an immense, ancient cave in near pristine condition, contains sulfur, iron, and manganese deposits and extremely low nutrient environments harboring diverse microbial life. The carbonate wallrock and overlying corroded limestone provide an excellent model for studying how life has survived, adapted, and altered this rock environment. Preliminary evidence suggests that the diverse community of microorganisms inhabiting corrosion residues includes fungi and bacteria that live by using manganese and iron. We are investigating the nature of the unusual microorganisms present, the means by which they adapt to their extreme environment, the energy sources that they use, and the overall level of biological activity of the communities. Because of the potential for subsurface life on other planets and possible chemical similarity to Lechuguilla Cave, our research will also explore the relevance of cave communities to those that may exist elsewhere.

We are currently using Scanning Electron Microscopy (SEM) and Electron Dispersive Spectroscopy (EDS) analysis to study sites in Lechuguilla Cave to search for evidence of bacteria and their potential energy sources. Preliminary results are available for four sites:

EA survey
site near the junction of the three major branches of the cave that has brownish-black and red corrosion residue.
FN survey
site in the Southwestern Branch of the cave that has a variety of colors of corrosion residue, including ochre, salmon, and red corrosion residues.
Red Lake
site in the Western Branch of the cave that has brillant red corrosion residue.
site in the Western Branch of the cave that has red, ochre, and black corrosion residues.

For more information about Lechuguilla:

The Lechuguilla Cave Human Impact Study

For questions or comments, please send mail to: diana@i-pi.com