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Taxonomic Characterization of Bacterial Communities in Periphyton Colonized in Tampa Bay Estuaries Receiving Runoff from Different Landscapes
Citation:
Houghton, K., F. Genthner, J. James, S. Friedman, AND R. Devereux. Taxonomic Characterization of Bacterial Communities in Periphyton Colonized in Tampa Bay Estuaries Receiving Runoff from Different Landscapes. American Society for Microbiology General Meeting, New Orleans, LA, May 30 - June 02, 2015.
Impact/Purpose:
Sharing results with fellow researchers investigating microbial ecology and nutrient response
Description:
Chemical, physical, and biological properties of periphyton (algae, cyanobacteria, and other microorganisms attached to surfaces) formed in aquatic ecosystems are often used as ecological indicators of anthropogenic disturbances from the landscape. Little attention has been paid to bacteria in periphyton due to difficulties in resolving bacterial community structure. The objective of this study was to use next generation sequencing technology to examine periphyton bacterial communities for potential indicators of environmental degradation. Periphyton was allowed to grow on Plexiglas plates for ten days in waters receiving runoff from nominally defined landscapes (reference, agricultural, and urban) in which environmental parameters, indicative of trophic status, were measured. Genomic DNA was extracted from the periphyton, 16S rRNA gene was PCR amplified using universal bacterial primers, and amplicons were sequenced. Sequences were processed using mothur and statistical analyses were performed with Primer-E v6. CLUSTER analysis showed that periphyton bacterial communities did not strictly cluster based on landscape runoff. Five distinct groupings were observed in the cluster analysis, with U05 and A02 both showing no similarities to any other sites. Among sites, U05 and A02 had the highest concentrations of dissolved inorganic nitrogen (DIN). Periphyton samples U05 and A02 showed similarities in their bacterial genera that were distinctly different from the bacterial genera found in all other samples. When correlated to the measured physicochemical environmental parameters, a combination of five parameters explained the bacterial community assemblage patterns observed in the cluster analysis. These parameters were chlorophyll a concentrations (in periphyton), temperature, salinity, DIN (in water), and site latitude. Total organic carbon in periphyton, commonly used to measure trophic status, did not strongly correlate to community composition. This suggests that local environmental conditions at sites along an estuarine gradient of changing environmental parameters may have had a stronger influence on the communities than adjacent land uses.