Angelina Rose Giannetto, Lauren E. Piper


Presentation: 9:00-10:15, Kennedy Union Ballroom



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Listeria monocytogenes is a bacterial foodborne pathogen that can cause severe enteric infections with high mortality rates. During transmission, L. monocytogenes is exposed to propionate both as a common additive in food matrices and as a metabolic byproduct of our intestinal microbiota. However, how L. monocytogenes adapts to propionate exposure is not fully understood. In this study, we investigated how propionate exposure regulates the activity of lactate dehydrogenase (LDH). LDH activity is critical for bacteria to maintain redox homeostasis and therefore can be a good indicator for bacterial fitness. Therefore, bacteria grown under different conditions with or without propionate were harvested and lysed. LDH activities were quantified in the resulting lysates using Pierce LDH Cytotoxicity Assay Kit. Moreover, to explore the molecular mechanism underlying the regulation of LDH activity, I compared the results between wildtype L. monocytogenes and a mutant strain lacking the transcription factor CodY. We found that while propionate didn't significantly change LDH activities, the lack of CodY resulted in a significantly lower LDH activity. These results highlight the potential role of CodY in activating LDH production.

Publication Date


Project Designation

Independent Research

Primary Advisor

Yvonne Y. Sun

Primary Advisor's Department



Stander Symposium, College of Arts and Sciences

The role of CodY in regulating Listeria monocytogenes lactate dehydrogenase activity in response to propionate