Recovery and Characterization of Microbiota from Rainer Mesa, Nevada Test Site

Résumé du livre

The potential for the bioremediation of contaminated subsurface environments has led to investigations of the microbial ecology of various subsurface environments throughout the United States, including arid western regions. Initial research was conducted in uncontaminated sites and findings were to be compared with those from contaminated areas. Tunnel systems within the deep subsurface of Rainier Mesa Nevada Test Site, afforded a unique opportunity to study microbial ecology because large amounts of material could be aseptically sampled with relative ease compared to drilling operations. Analysis of microbial communities along an elevational gradient included characterization of surface soil, a paleosol, volcanic rock (from outcrop), zoelitized subsurface rock, fracture flow water, and out flow spring water. The samples taken from these sites provided evidence that endolithic bacterial communities within the deep subsurface of Rainier Mesa have been in place for long periods of time. An analysis of subsurface samples indicated that the recoverable microbial communities increased in abundance and decreased in communities increased in abundance and decreased in diversity with prolonged storage. The heterogeneous distribution of microbiota in zeolitized rock with negligible water flux, and the recovery of new bacterial types as a result of storage related phenomena, provide mounting evidence that the bacteria extant within the subsurface of Rainier Mesa were dormant bacterial types. These bacteria may have survived for extended periods of time, but because they may be isolated in microhabitats as dormant forms, they may not be influenced by or be influencing their current surroundings.--Adapted from abstract.