429 Characterization of Microorganisms and Organic Matter Present in Waste Isolation Pilot Plant (WIPP) Halite

Friday, November 6, 2009: 3:40 PM
Hereford (Camino Real Hotel)
Darlene D. Martin, MS , Department of Biology, New Mexico State University, Las Cruces, NM
Juliet Swanson, PhD , Los Alamos National Laboratory, Carlsbad, NM
Rami Al-Khatib, MS , Electron Microscopy Laboratory, New Mexico State University, Las Cruces, NM
Peter Cooke, PhD , Electron Microscopy Laboratory, New Mexico State University, Las Cruces, NM
Donald R. Reed PhD , Los Alamos National Laboratory, Carlsbad, NM
Geoffrey B. Smith PhD , Department of Biology, New Mexico State University, Las Cruces, NM
The Waste Isolation Pilot Plant (WIPP) is a permanent nuclear waste repository near Carlsbad, New Mexico.  This repository is located within the Salado Formation, a Permian Age halite bed dated at 250 million years old.  The goal of this study is to characterize the microorganisms in the whole halite and halite inclusion fluid and also to survey the presence of other nonviable organic matter.  Nucleic acids extracted from the whole halite reveal little bacterial diversity and no archaeal signature; however, cultivation of organisms from the whole halite shows the reverse trend.  A technique has been developed for the sterilization of halite crystals in order to distinguish between organisms present in whole halite versus inclusion fluids.  Studies are underway to characterize the microorganisms within these trapped fluids.  Transmission and scanning electron micrographs (TEM and SEM) of these inclusions reveal the presence of numerous fibers ranging from thin and elliptical to amorphous in shape.  In addition, energy dispersive spectroscopy (EDS) has confirmed a difference in the elemental chemistry composition between the solid salt matrix and the encased seawater.