Bdellovibrio has one of the highest energy efficiencies known. Attack phase Bdellovibrio cells are extremely motile, and die swiftly under anaeobic or microaerophilic conditions. Many Bdellovibrio species are know to swiftly possess catalase and super oxcide dismutase (oxygen detoxifying) enzymes. By knocking out the catalase gene in Bdellovibrio, we believe that the bacterium will not be able to survive the stresses experienced inside the periplasm of host cells and the outside environment during its attack phase. Thus the question is:Can we clone a catalae gene from out Bdellovibrio genomic library, using E.coli catalase mutant and functional complementation? With the E.coli strain (UM2) and plasmid confirmed by the catalase test (hydrogen peroxide), the gene will be mutagenized by in-vitro transposon mutagenesis, subcloned, sequenced, and through allelic replacement, the mutant copy of the catalse gene will be transferred to Bdellovibrio.With the mutant copy now withing Bdellovibrio, we can confirm how the catalase gene affects the different stages of the Bdellovibrio life cycle.