The following is an example of a student’s formal abstract.

This project is the work of Laura Daum, who was the overall winner of the 2004 ASHSSS. It is a continuation of the project she presented at the 2003 ASHSSS.

Growth and Mineralization Characteristics of Toluene and Diesel-Degrading Bacteria from Williams Refinery Groundwater
Laura Daum
West Valley High School, Fairbanks, AK
Mentor : Dr. Sharon Richmond
Teacher: Ms. Cyndie Beale

Through bioremediation, naturally occurring bacteria can help restore the water quality of aquifers contaminated by leaking petroleum tanks. This project’s purpose was to determine the optimal growth temperature and mineralization rate (rate at which the bacteria turn hydrocarbon into water and CO 2 ) for hydrocarbon-degrading bacteria from 4.5 șC contaminated groundwater under Williams Refinery in North Pole, Alaska. Last year, the optimal growth temperatures were found to be between 11 and 15 șC for the toluene-degrading bacteria and 11 șC for the diesel-degraders. The aerobic mineralization rate was 0.046 mg of 14C-hexadecane per day per mL, with a density of 5.3 x 10 6 cells per mL. This year, the project’s purpose was to determine whether the diesel-degrading bacteria could grow anaerobically and if their mineralization rate was faster aerobically or anaerobically. A nitrate reduction test was performed to test the hypothesis that the bacteria could grow anaerobically, using nitrate as a terminal electron acceptor. The anaerobic mineralization rate of 14C-hexadecane was calculated using radiorespirometry. This mineralization rate was then compared to the aerobic mineralization rate determined last year. The diesel-degrading bacteria were able to grow anaerobically using nitrate and the anaerobic mineralization rate was 0.018 mg of 14C-hexadecane per day per mL, with a density of 5.3 x 10 6 cells per mL. The anaerobic mineralization rate was significantly less than the aerobic mineralization rate. The results from this project could be useful in the bioremediation of contaminated sites with similar environmental characteristics.