Phylogenetic analysis of hyperthermophilic natural populations using ribosomal RNA sequences. Final report, July 15, 1995--July 14, 1996

摘要

It has become clear over the past few decades that substantial microbial diversity occurs at very high temperatures. Hyperthermophilic organisms (temperature optima > 80(degrees)C) promise a wealth of unknown biochemistry and biotechnological potential, and challenge our comprehension of biomolecular structure. Nonetheless, relatively little is known about the diversity of life at high temperatures because of a traditional problem in microbial ecology; inability to cultivate naturally occurring organisms. Molecular techniques have recently been developed, however, that allow the detection and some characterization of organisms without cultivation. Limited surveys of hyperthermophilic communities using such techniques have revealed the existence of an unexpected plethora of organisms, some profoundly different from known ones. The main objective of the proposed program is to continue to characterize, phylogenetically and quantitatively, without cultivation, the constituents of ecosystems that are known to be associated with particular high-temperature sites. Main focus is on the Yellowstone geothermal system.