Center for Biofilm Engineering
Abstract:
"Composition and Diversity of Microbial Communities Recovered from Surrogate
Minerals Incubated in an Acidic Uranium-Contaminated Aquifer"
04-037 Our understanding of subsurface microbiology is hindered by the inaccessibility
of this environment, particularly when the hydrogeologic medium is contaminated
with toxic substances. In this study, surrogate geological media contained
in a porous receptacle were incubated in a well within the saturated zone of a
pristine region of an aquifer to capture populations from the extant
communities. After an 8-week incubation, the media were recovered, and the
microbial community that developed on each medium was compared to the
community recovered from groundwater and native sediments from the same region
of the aquifer, using 16S DNAcoding for rRNA (rDNA)-based terminal restriction
fragment length polymorphism (T-RFLP). The groundwater and sediment
communities were highly distinct from one another, and the communities that
developed on the various media were more similar to groundwater communities than
to sediment communities. 16S rDNA clone libraries of communities that developed
on particles of a specular hematite medium incubated in the
same well as the media used for T-RFLP analysis were compared with those
obtained from an acidic, uraniumcontaminated region of the same aquifer.
The hematite-associated community formed in the pristine area was highly diverse
at the species level, with 25 distinct phylotypes identified, the majority of
which (73%) were affiliated with the β-Proteobacteria.
Similarly, the hematite-associated community formed in the contaminated area was
populated in large part by β-Proteobacteria
(62%); however, only 13 distinct phylotypes were apparent. The three
numerically dominant clones from the hematite-associated community from the
contaminated site were affiliated with metal- and radionuclide-tolerant or
acidophilic taxa, consistent with the environmental conditions. Only two
populations were common to both sites.
Reardon, C.L., D.E. Cummings, L.M. Petzke, B.L. Kinsall, D.B. Watson, B.M.
Peyton, and G.G. Geesey, "Composition and Diversity of Microbial Communities
Recovered from Surrogate Minerals Incubated in an Acidic Uranium-Contaminated
Aquifer," Appl. Environ. Microbiol., 70(10):6037-6046 (2004) |
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