The Effect of the zwf Gene on Bacteriophage Replication

Abstract

Viruses rely on host cell metabolism to replicate efficiently. The zwf gene encodes glucose-6-phosphate dehydrogenase, which drives the pentose phosphate pathway to produce NADPH and ribose-5-phosphate for growth and nucleotide synthesis. Disrupting zwf can alter bacterial metabolism and phage replication. Investigating the role of the zwf gene has important implications for cancer research and for phage therapy, which uses bacteriophages to target antibiotic-resistant bacteria. The objective of this project is to determine how deletion of the zwf gene in E. coli affects bacteriophage replication under nutrient-rich and nutrient-limited conditions. We hypothesized that loss of zwf would reduce phage replication by limiting NADPH and ribose-5-phosphate needed for nucleotide synthesis and redox balance. We used a parent E. coli strain and a zwf knockout strain grown in LB media and M9 minimal media. Growth rates were compared by measuring absorbance at OD600 using a spectrophotometer. Both strains were infected with T2 bacteriophage. Samples were centrifuged at different time points, and supernatants were used to compare the efficiency of replication. T2 phage was used in serial dilutions to plate double-agar overlay assays that produce plaques indicating cell lysis. The zwf knockout and parent strain showed similar growth in nutrient-rich conditions and similar lysis curves across all phage treatments, indicating that zwf is non-essential for growth and does not significantly affect lysis rate. Plaque assays indicated reduced plaque formation in the zwf knockout, suggesting decreased phage replication efficiency. This finding is novel and broadens the understanding of how host metabolism affects viral replication. Future research should further analyze NADPH levels and the role of metabolic pathways in bacteriophage replication. This work provides insight into how bacterial metabolic pathways shape phage replication and may help guide the selection of metabolically resilient phages for phage therapy.