1. To discover representatives of new prokaryotic taxa.
2. To determine patterns of prokaryotic diversity and their relationship to land use.
3. To determine if certain components of the prokaryotic community are ubiquitous irrespective of land usage and the taxonomic level of this ubiquity.
4. To add a prokaryotic component to the projects being carried out at the CAP-LTER site.
5. To provide training for graduate students and research experience for undergraduate students.
16S rDNA GENE CLONE LIBRARY ANALYSIS
One approach taken in this project to look at the overall diversity of
the bacterial communities of the CAP-LTER was the use of 16S rRNA gene
clone libraries on a large number of samples. 16S rRNA gene clone libraries
of 23 CAP LTER soils of varying land use type were constructed, generating
up to 500 clones per sample(View).
ARDRA was performed using two restriction enzymes for resolution of the
phylogeny of 16S rRNA gene clones, and unique ARDRA patterns were sequenced
to obtain an overall phylogenetic composition of the clone library.
BACTERIAL BIOGEOGRAPHY AND THE
DETECTION OF UBIQUITOUS TAXA AT THE CAP- LTER
Due to the diverse assemblage of landscapes in the CAP LTER created by
anthropongenic disturbances via agriculture and urbanization, and the
observed changes in phylum-level diversity within the entire region, we
hypothesized that the distribution of lower-level bacterial groups would
be spatially restricted based upon their ability to survive within a limited
number of land use types. Using phylotypic data collected from constructed
16S rRNA gene libraries, we generated phylogenetic trees for all major
bacterial taxa found in the CAP LTER to catalog the phylogenetic diversity
of bacterial phylotypes, and recorded the presence and abundance of significant
phylotypic groups across land use types.
DETECTION OF UBIQUITOUS TAXA ACROSS THE CAP LTER
ARDRA fingerprints that were detected in a clear majority (>75%) of 16S rDNA clone libraries and within four of the major land use types (agricultural, open, remnant, urban) were used as models for the design of phylotype-specific PCR reactions to test the presence of these taxa in the remaining 167 CAP LTER soil samples collected.