Expanding the Metabolic Repertoire of Pseudomonas aeruginosa: Evidence for Pyroglutamate Utilization
Faculty Mentor
Benjamin Lundgren
Presentation Type
Poster
Start Date
4-14-2026 2:00 PM
End Date
4-14-2026 4:00 PM
Location
PUB NCR
Primary Discipline of Presentation
Chemistry and Biochemistry
Abstract
Pseudomonas aeruginosa is a metabolically versatile opportunistic pathogen capable of utilizing diverse nutrient sources, a flexibility that contributes to its survival in various environments. While the catabolism of preferred nutrient sources like gluconate are well-characterized, the pathways for metabolizing non-preferred, alternative nutrients such as pyroglutamate (5-oxoproline) remain less understood. This study had two primary objectives: first, to determine if P. aeruginosa PAO1 can utilize pyroglutamate as an exclusive nutrient source, and second, to identify conditions that induce expression of the PA2114-PA2113-PA2112-PA2111-PA2110 operon, which encodes for proteins hypothesized to be involved in pyroglutamate catabolism. To test the first hypothesis, P. aeruginosa PAO1 was grown in minimal media containing pyroglutamate as the sole nutrient source and cell density was periodically measured. For the second hypothesis, enhanced-yellow fluorescent protein reporters were constructed to measure expression of the PA2112, PA2113, and PA2114 genes. P. aeruginosa containing these reporters were grown under various conditions: peroxide stress, exogenous glutathione, and both preferred and non-preferred nutrient sources. Our results demonstrate that P. aeruginosa can indeed metabolize pyroglutamate, as evidenced by significant protein production in these cultures, confirming its ability to funnel this non-preferred substrate into central nutrient metabolism. To investigate the genetic basis of this pathway, our ongoing work involves constructing a transcriptional reporter. We are employing molecular cloning techniques to fuse putative promoter regions, identified through bioinformatic analysis of the 5-oxoprolinase gene cluster, to the gene for enhanced yellow fluorescent protein (eyfp). Successful cloning and integration of these reporter constructs will allow for the quantitative, fluorescence-based measurement of gene expression under inducing conditions. This research aims to biochemically characterize the 5-oxoprolinase operon, providing insight into the genetic regulation of metabolic flexibility in P. aeruginosa.
Recommended Citation
Slotten, Kyle; Hammami, Noure; and Woudenberg, Chase, "Expanding the Metabolic Repertoire of Pseudomonas aeruginosa: Evidence for Pyroglutamate Utilization" (2026). 2026 Symposium. 16.
https://dc.ewu.edu/srcw_2026/ps_2026/p3_2026/16
Creative Commons License
This work is licensed under a Creative Commons Attribution-NonCommercial-No Derivative Works 4.0 International License.
Expanding the Metabolic Repertoire of Pseudomonas aeruginosa: Evidence for Pyroglutamate Utilization
PUB NCR
Pseudomonas aeruginosa is a metabolically versatile opportunistic pathogen capable of utilizing diverse nutrient sources, a flexibility that contributes to its survival in various environments. While the catabolism of preferred nutrient sources like gluconate are well-characterized, the pathways for metabolizing non-preferred, alternative nutrients such as pyroglutamate (5-oxoproline) remain less understood. This study had two primary objectives: first, to determine if P. aeruginosa PAO1 can utilize pyroglutamate as an exclusive nutrient source, and second, to identify conditions that induce expression of the PA2114-PA2113-PA2112-PA2111-PA2110 operon, which encodes for proteins hypothesized to be involved in pyroglutamate catabolism. To test the first hypothesis, P. aeruginosa PAO1 was grown in minimal media containing pyroglutamate as the sole nutrient source and cell density was periodically measured. For the second hypothesis, enhanced-yellow fluorescent protein reporters were constructed to measure expression of the PA2112, PA2113, and PA2114 genes. P. aeruginosa containing these reporters were grown under various conditions: peroxide stress, exogenous glutathione, and both preferred and non-preferred nutrient sources. Our results demonstrate that P. aeruginosa can indeed metabolize pyroglutamate, as evidenced by significant protein production in these cultures, confirming its ability to funnel this non-preferred substrate into central nutrient metabolism. To investigate the genetic basis of this pathway, our ongoing work involves constructing a transcriptional reporter. We are employing molecular cloning techniques to fuse putative promoter regions, identified through bioinformatic analysis of the 5-oxoprolinase gene cluster, to the gene for enhanced yellow fluorescent protein (eyfp). Successful cloning and integration of these reporter constructs will allow for the quantitative, fluorescence-based measurement of gene expression under inducing conditions. This research aims to biochemically characterize the 5-oxoprolinase operon, providing insight into the genetic regulation of metabolic flexibility in P. aeruginosa.
