Hodson, R. E. University of Georgia, rhodson@arches.uga.edu
Chen, F. E. University of Georgia, fchen2@arches.uga.edu
Dustman, W. University of Georgia, wdustman@arches.ugae.edu

Bacterial communities along a salinity gradient (0 to 30 ) on the Satilla River in southern Georgia were analyzed by in situ reverse transcription (ISRT) using primers specific for the beta, gamma, delta, marine alpha proteobacteria, and for all eubacteria. Bacteria giving a positive ISRT reaction with the eubacterial primer accounted for 76, 43, and 85% of total DAPI-positive cells at stations with salinities of 34.8, 24.6, and 0 , respectively. Marine alpha-positive bacteria were most numerous (32 % of eubacteria) at the highest salinity and least abundant (<1%) in freshwater stations. Gamma-proteobacteria accounted for 33, 42, and 23 % of eubacteria, and Beta-group accounted for 13, 19, and 41% eubacteria at the stations with salinities of 34.8, 24.6, and 0 . Delta-proteobacteria were less than 9% of eubacteria at all salinities. ISRT was also used to detect the proportion of the marine bacterial community that was actively expressing genes for degradation of a mixture of aromatic hydrocarbons (benzene, ethanol, toluene, and xylene). In unamended estuarine water, no bacteria expressing genes for degradation of the hydrocarbons were detected. After exposure to the hydrocarbon mixture for one week, 20-30% of the total bacterial cells showed expression of this degradative system.
Day: Tuesday, Feb. 2
Time: 02:00 - 02:15pm
Location: Sweeney Center
Code: SS41TU0200S