Presentation Type
Poster
Faculty Mentor’s Full Name
Brian Bothner
Faculty Mentor’s Department
Department of Chemistry & Biochemistry MSU
Abstract / Artist's Statement
Although Escherichia coli is a well-studied bacteria in the world of microbiology, there are still unknowns about its metabolism. For example, global changes during the transition from aerobic to anaerobic respiration with respect to pathways outside central carbon metabolism are poorly documented. In this research, I investigated the change in cell membrane lipid composition when aerobic cultures of Escherichia coli were put under anaerobic conditions.
To set a baseline, my co-author and I incubated Escherichia coli in batches of 18, dividing the groups into 3 and taking UV-Vis measurements of colony growth at timepoints 3hrs, 4.5hrs, and 5hrs+. Half of the flasks were exposed to environmental oxygen while the other half were sealed with rubber stoppers. We planned to observe the transition of aerobic to anaerobic respiration, so we did not flush the sealed flasks with nitrogen gas. The growth curves indicated a slowdown of cell growth when oxygen was suspected to be depleted from the sealed flasks, but a resurgence of growth after a period of time. We collected 72 total samples over the course of 4 days. Cells were harvested at 3 hours, 4.5 hours, and 5 hours and then stored as frozen pellets.
Half of these pellets were then sonicated and the lipid membrane was extracted via Folch lipid extraction. Samples of intact cells were analyzed directly with MALDI-MS. We determined there was a greater degree of unsaturation in the lipids from the anaerobic samples as compared to the aerobic samples, indicating a change from a more saturated phospholipid to a less saturated one.
This project has laid the groundwork for future study of Escherichia coli lipid membrane transition. Escherichia coli is pathogenic in its anaerobic form in the human gut. Therefore, further research could explore therapies that could disrupt the Escherichia coli cell membrane transition as a treatment for Escherichia coli-caused food poisoning or other maladies.
Category
Life Sciences
Assessing Lipid Composition of Cell Membranes in Escherichia coli under Aerobic and Anaerobic Conditions
UC South Ballroom
Although Escherichia coli is a well-studied bacteria in the world of microbiology, there are still unknowns about its metabolism. For example, global changes during the transition from aerobic to anaerobic respiration with respect to pathways outside central carbon metabolism are poorly documented. In this research, I investigated the change in cell membrane lipid composition when aerobic cultures of Escherichia coli were put under anaerobic conditions.
To set a baseline, my co-author and I incubated Escherichia coli in batches of 18, dividing the groups into 3 and taking UV-Vis measurements of colony growth at timepoints 3hrs, 4.5hrs, and 5hrs+. Half of the flasks were exposed to environmental oxygen while the other half were sealed with rubber stoppers. We planned to observe the transition of aerobic to anaerobic respiration, so we did not flush the sealed flasks with nitrogen gas. The growth curves indicated a slowdown of cell growth when oxygen was suspected to be depleted from the sealed flasks, but a resurgence of growth after a period of time. We collected 72 total samples over the course of 4 days. Cells were harvested at 3 hours, 4.5 hours, and 5 hours and then stored as frozen pellets.
Half of these pellets were then sonicated and the lipid membrane was extracted via Folch lipid extraction. Samples of intact cells were analyzed directly with MALDI-MS. We determined there was a greater degree of unsaturation in the lipids from the anaerobic samples as compared to the aerobic samples, indicating a change from a more saturated phospholipid to a less saturated one.
This project has laid the groundwork for future study of Escherichia coli lipid membrane transition. Escherichia coli is pathogenic in its anaerobic form in the human gut. Therefore, further research could explore therapies that could disrupt the Escherichia coli cell membrane transition as a treatment for Escherichia coli-caused food poisoning or other maladies.