The Impact of Phosphate Limitation on Transcriptional Burden and Growth in Escherichia coli
Board Location: #54
Discipline: Chemical Sciences
Subcategory: biochemistry
Session: 3
Aouss Azzouz - Earlham College
Microbial communities drive the cycling of nutrients in soils, oceans, and human hosts. These communities experience environmental variations, such as changes in nutrient inputs, which necessitate adaptive responses. Understanding these adaptations and how nutrient availability influences bacterial physiology is crucial for both ecological and medical studies. This research investigates the effects of phosphate limitation on Escherichia coli growth dynamics. By employing antibiotic-based assays, the study aims to elucidate the specific transcriptional burdens imposed under these nutrient-restricted conditions.
E. coli strains were cultured in defined media with varying phosphate levels to determine the optimal limitation. A novel agar diffusion auto-delivery principle was developed for this process. This method, an alternative to fed-batch methods, requires no external source and enables multiple condition experimentation in microwell plates. Cultures were tested with the antibiotics Rifampicin and Chloramphenicol, targeting RNA polymerase and ribosomes, respectively. Growth rates were measured in 96-well plates at OD600, and statistical analysis determined antibiotic-related stress.
Preliminary findings indicate that phosphate limitations can alter E. coli growth rates and MIC values. This supports our hypothesis that growth in phosphate-limited conditions shifts the burden from translation to transcription, limiting the cells’ ability to respond to environmental changes through gene expression and favoring other means of adaptation.
Microbial communities are among the most complex phenomena on the planet, and this study contributes to a principled understanding of their adaptation to nutrient stress. Future research will explore different bacterial species and the impact of nitrogen limitation on translational burdens.
This research was supported by the Summer Research Opportunities Program (SROP) through the Big Ten Academic Alliance. Funding for this program was provided by The Ohio State University SROP.
Funder Acknowledgement(s): This research was supported by the Big Ten Academic Alliance through the Summer Research Opportunities Program (SROP) at The Ohio State University. The program provided funding and resources to support independent, student-driven research initiatives aimed at fostering innovation and academic excellence.
Faculty Advisor: Karna Gowda, gowda.51@osu.edu
Role: This research was independent work conducted by me and my PI. I played a leading role in every aspect of the research, including designing the study, developing the hypothesis, and conducting a thorough literature review to establish the project's foundation. I cultured Escherichia coli strains under varying phosphate levels, implemented a novel agar diffusion auto-delivery method, and performed all experimental assays with antibiotics to assess transcriptional and translational burdens. I collected, analyzed, and interpreted data, including growth rates and MIC values, using statistical methods. Additionally, I synthesized findings into actionable conclusions, prepared the final presentation materials, and identified future research directions.