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Cave Geomicrobiology
and Biogeochemistry Research Louisiana State University, Geomicrobiology & Environmental Microbiology Studies Group
Louisiana State University E235 Howe-Russell Geoscience Complex Louisiana State University Baton Rouge, LA 70803 office: 225-578-2469 fax: 225-578-2302 |
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Once considered a matter of fiction, scientists are now confident that microbial life inhabits nearly every environment on Earth, with millions of estimated microbial species occurring worldwide. The subsurface is one of the Earth's major habitats, defined by some researchers as being greater than 8 meters depth for terrestrial settings and more than 10 cm depth for marine settings. Surface habitats coupled relatively constant temperatures and protection from potentially harsh surface conditions (e.g., UV radiation) with an abundance of inorganic solutes and mineral surfaces that can serve as energy and nutrient sources for microbes. Despite recent scientific advances to identify microbes from surface habitats and to reconstruct phylogenetic relationships, the diversity and types of microbes, as well as the metabolic capabilities of microbes, are still poorly understood. One reason for this is that the surface is difficult to access. Caves, however, are windows into the subsurface which can allow scientists to access the subsurface. Cave exploration does not usually require expensive equipment, and microbial communities living in the caves can be directly examined, sampled, and manipulated. Microbiological and geological investigations in cave and karst systems have successfully been conducted for >50 years, and recently sampling strategies to lessen human impact. |
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Microbial diversity of subterranean ecosystems Lower Kane Cave, Wyoming |
Inquire with Dr. Engel if you are interested in the work. |
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The Frasassi Cave system near Gubbio, Italy, provides an excellent molecular and ecophysiological comparison to Lower Kane Cave in the USA. We have been studying the microbial diversity of the Frasassi caves since 1997. Microbial mats in the Frasassi caves are distributed throughout the aphotic habitat, as well as in the emergent surface spring (photic habitat), along nearly a kilometer-long flow path. Our work has revealed that the microbial communities in Frasassi system , dominated by Epsilonproteobacteria are closely-related to microbes in Lower Kane Cave, half a world away! The Frasassi Caves: website designed and managed for tourists interested in the caves Pictures from 2005 Field Work and Research Results
Other
Sulfidic Caves |
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Microbially-enhanced secondary porosity in karst Karst is important globally for groundwater and petroleum reservoirs, and appreciating how karst terrains evolve through time will aid in understanding of where new resources may exist. Some of the world’s most productive oil reserves are found in carbonate rocks having significant secondary porosity, perhaps generated by sulfuric acid.
Based
on research from Lower Kane Cave, Wyoming, significant dissolution of
carbonate occurs in the presence of active sulfur-oxidizing bacteria
that colonize subaqueous carbonate surfaces. The sulfur-oxidizers
survive at extremely low PO2, suggesting that karstification
may occur at much greater aquifer depths in the absence of oxygen. We
are testing the hypothesis that sulfur-oxidizers are modifying karst
porosity in the Edwards and Trinity Aquifers of Central Texas.
Edwards Aquifer Research at LSU
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and has been partially supported by the Council on Research, Faculty Research Grant, LSU. Inquire with Dr. Engel if you are interested in the work. |
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Cave and Karst Organizations and Links
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Iron-rich microbial mats in Lower Kane
Cave. |
Links to Other Cave Geomicrobiology Research Programs in the USA
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  Please contact Dr. Annette Engel for more information regarding the research or photographs. Call (225) 578-2469 or email. Address: Department of Geology and Geophysics, Louisiana State University, Baton Rouge, LA 70803. |
| ©AS Engel2007 |
