Hidden underneath the hilly grasslands studded with ocotillos and mesquite trees in southeastern Arizona lies a world shrouded in perpetual darkness: Kartchner Caverns, a limestone cave system renowned for its untouched cave formations, sculpted over millennia by groundwater dissolving the bedrock and carving out underground rooms, and passages that attract tourists from all over the world.
Beyond the reaches of sunlight and seemingly devoid of life, the caves are in fact teeming with an unexpected diversity of microorganisms that rival microbial communities on the earth's surface, according to a new study led by University of Arizona researchers that has been published in the journal of the International Society for Microbial Ecology. The discovery not only expands our understanding of how microbes manage to colonize every niche on the planet but also could lead to applications ranging from environmental cleanup solutions to drug development.
"We discovered all the major players that make up a typical ecosystem," said Julie Neilson, an associate research scientist in the UA's College of Agriculture and Life Sciences. "From producers to consumers, they're all there, just not visible to the naked eye."
In a long-standing collaboration between Kartchner Caverns State Park and the UA, Neilson and her co-workers have spent years exploring the underground world and its inhabitants. For their latest study, they swabbed stalactites and other cave formations for DNA analysis. Based on the genes they found in their samples, they reconstructed the bacteria and archaea - single-celled microorganisms that lack a cell nucleus - living in the cave. Kept secret for 14 years after its discovery in 1974 by two UA graduate students who were hiking in the Whetstone Mountains just south of Benson, Ariz., Kartchner Caverns has been protected from human impact so that scientists can study the fragile environment and organisms inside the cave.
|Contact: Daniel Stolte|
University of Arizona