A comparison of small subunit 16S ribosomal DNA recombinant plasmid clone libraries from High Point City Lake, North Carolina

Studies of aquatic communities represent a unique method of monitoring the health of water resources. High Point City Lake small subunit 16S ribosomal DNA clone libraries were compared across small spatial and temporal scales. This study used polymerase chain reaction and shotgun cloning to isolate individual 16S rDNA sequences. A total of 437 operational taxonomic units were found in this study. Among all libraries 84 sequences demonstrated affiliation to the phylum Proteobacteria, including representatives from the classes alpha, beta, delta, and gamma. The next most abundant category of putatively identified 16S ribosomal DNA was 24 sequences affiliated with the class Actinobacteria. Seventeen sequences demonstrated similarity to clones previously isolated from Crater Lake, CA bacterium.; These findings suggest that variability among the replicate libraries may be a reflection of the small library size. SCHAO1 and S ACE diversity estimators suggest larger libraries would be required to achieve a stable estimate of OTUs, but given the small size of each of the replicate libraries their similarity values were not unexpected. Variability among clone libraries from diurnal samples taken at the same location was low. Variability among clone libraries across short spatial scales showed suggested little difference among samples in well mixed areas of the lake, but one library may have reflected the influence of a tributary inflow. Overall, these data suggest that the 16S rDNA libraries were similar to one another.