Investigating the Role of Glutamine Metabolism on Bacteriophage Replication

Abstract

The emergence of antimicrobial resistance demands more effective alternative treatments such as phage therapy. To further explore treatments, this research attempts to better understand bacteriophage replication. The TCA cycle is a crucial metabolic pathway in E. coli, responsible for providing bacteria with energy, which includes pathways such as glutamine-synthesis and glutamine degradation. It is known that bacteriophage requires energy and nutrients to perform viral replication. We chose to knock out genes glnA (present in glutamine-synthesis), glsA, and glsB (both present in glutamine degradation). This research examines the importance of glutamine in these metabolic pathways. To determine the role of glutamine in T4 bacteriophage replication, growth and phage replication dynamics in the different strains were compared. Growth and lysis curves were conducted in rich LB media to understand patterns in optimal nutrient conditions, while also in M9 minimal media with a small glucose concentration and varied glutamine concentrations. This data was used to determine optimal glutamine concentrations for growth and lysis. Phage replication differences in the strains were further analyzed via phage titer and burst size. The glsB strain showed increased phage replication, and glnA had decreased replication. These results indicate what genes are necessary for optimal phage replication. Our research will assess the selected knockout genes to understand which aspects of the metabolic pathway are more influential on bacterial lysis. Further research will help illuminate the role of glutamine metabolism in T4 phage replication and have implications for improving phage therapy.