Salinity and Temperature Tolerance of Environmental Isolates of Escherichia coli
College
College of Arts and Sciences
Department
Biology
Faculty Mentor
Dr. Matthew Heard
Abstract
Recent studies have shown that Escherichia coli (E. coli) is able to survive in sandy oceanic beach environments. We were interested in understanding how E. coli survives in these dynamic ecosystems. Oceanic beaches have several important environmental stressors including light, temperature, salinity and nutrient availability, which can influence the survival of E. coli. In this study, we examined how two of these stressors, temperature and salinity, affect the growth and survival of E. coli. To do this, we utilized a factorial laboratory experiment. In our factorial approach, we exposed six different environmental isolates of E. coli (collected from Folly Beach, SC) to varying levels of temperature and salinity. To assess how salinity affects E. coli growth, we exposed our six isolates to salt concentrations varying from 0-8% and determined the number of colony-forming units (CFUs) after an incubation period of 24 hours at 37oC. To assess how temperature affects E. coli growth, we exposed our six isolates to temperatures ranging from 4-50oC and determined the number of CFUs after 24 hours. Our findings show that growth and survival of E. coli was inhibited in salt concentrations greater than 5% and in temperatures that were less than 20oC and greater than 47oC.We also determined that there were interactive effects between salinity and temperature, but that salinity has a stronger influence on E. coli growth and survival. Collectively, our findings suggest that temperature and salinity are significant factors that can influence amination would also occur under the same conditions.
Honors Thesis Committee
Matthew Heard, Ph.D.; Victoria Frost, Ph.D.; Kristi Westover, Ph.D.
Start Date
22-4-2016 1:40 PM
End Date
22-4-2016 1:55 PM
Salinity and Temperature Tolerance of Environmental Isolates of Escherichia coli
West Center,Room 217
Recent studies have shown that Escherichia coli (E. coli) is able to survive in sandy oceanic beach environments. We were interested in understanding how E. coli survives in these dynamic ecosystems. Oceanic beaches have several important environmental stressors including light, temperature, salinity and nutrient availability, which can influence the survival of E. coli. In this study, we examined how two of these stressors, temperature and salinity, affect the growth and survival of E. coli. To do this, we utilized a factorial laboratory experiment. In our factorial approach, we exposed six different environmental isolates of E. coli (collected from Folly Beach, SC) to varying levels of temperature and salinity. To assess how salinity affects E. coli growth, we exposed our six isolates to salt concentrations varying from 0-8% and determined the number of colony-forming units (CFUs) after an incubation period of 24 hours at 37oC. To assess how temperature affects E. coli growth, we exposed our six isolates to temperatures ranging from 4-50oC and determined the number of CFUs after 24 hours. Our findings show that growth and survival of E. coli was inhibited in salt concentrations greater than 5% and in temperatures that were less than 20oC and greater than 47oC.We also determined that there were interactive effects between salinity and temperature, but that salinity has a stronger influence on E. coli growth and survival. Collectively, our findings suggest that temperature and salinity are significant factors that can influence amination would also occur under the same conditions.
