Abstract 1319 Investigating DNA Damage in Mn2+ Deficient Strains of E. Coli

The role of manganese in preventing DNA damage within E. coli aids in understanding the survival of bacteria to the human immune response and has the potential for antibiotic development. Presence of manganese has been shown to decrease the rates of oxidative mutations in the DNA of strains of E. coli such as CSH104. The MntH gene encoding for manganese transport protein was knocked out from E. coli strain CSH104 to inhibit its ability to intake manganese to produce the strain delta CSH104. The comet assay is a gel electrophoresis technique used to visualize DNA strand fragmentation within an individual cell. Comet assays were performed on CSH104 and delta CSH104 strains with hydrogen peroxide as a stressor to assess the effect of manganese deficiency on oxidative stress in E. coli. In contrast to the CSH104 strain, which is responsive to stressors such as hydrogen peroxide, CSH106 generates DNA strand breaks in reaction to UV light. Thus, the knockout method for the MntH gene in CSH104 was applied to the CSH106 strain to investigate the severity of light-induced oxidative damage in E. coli with a lack of manganese in the bacterial cells. This presentation will discuss the knockout of the MntH gene using Lambda-red recombination utilizing previous research that produced our manganese-deficient strain of CHS104. It will also briefly cover the analysis of comet assay-based visualization of CSH104 and delta CSH104.