MICROBIOLOGY
Archaea Diversity in the sediments of the Ledbetter Embayment Littoral Zone of
Kentucky Lake Reservoir. MARGARET GROSSER* and TIMOTHY JOHNSTON,
Department of Biological Sciences and the Center for Reservoir Research, Murray State
University, Murray, KY 42071.
Molecular techniques were applied to the study of the Archaea community in
sediment/soil samples from five sites within the littoral zone of Ledbetter Embayment,
one site above the flood plain, and one site within the embayment. DNA was extracted
directly from the samples, the rDNA amplified using Archaea specific primers, and the
amplified fragments cloned and sequenced. The sequences were identified by
comparison to the rRNA database. Ninety sequences showed above 91% identity to 10
methanogenic species of Archaea. No other groups of Archaea were found in these
samples. In order to determine if there are changes in the community as the temperature
or water-level changes, samples were taken monthly for one year, DNA extracted and
amplified as before, and the amplified DNA subjected to ARDRA analysis. Site-to-site
comparison found no differences within the littoral zone or when compared to the soil
sample and embayment sample. However, when the site data were pooled for each
month and then compared to all other months, the data showed significant differences
through the year. These data suggest that temperature and/or nutrient availability affect
the Archaea community of the littoral zone in this embayment rather than water level.