Construction of Catalase Double Knockout Escherichia coli Strain for Isogenic Strain Comparison Studies for the Role of Catalase

Abstract

Escherichia coli encodes for two catalases, katE and katG, that may mediate protection to damage from reactive oxygen species. Prior studies have attempted to assess the contribution of the individual catalases, albeit through comparison of knockout strains on non-isogenic backgrounds. This study aimed to generate a katE/katG double knockout strain on the wellcharacterized BW25113 E. coli K-12 strain background through Lambda Red recombination knockout of katG on an existing katE single knockout strain. Generation of double knockout was successful. The kanamycin resistance cassettes were then removed from the single and double knockouts via FLP-FRT recombination, to allow direct strain comparisons without extraneous phenotypes.