Attempted Transformation of Catalase-Deficient Escherichia coli with pBAD24 Vector Containing katE

Abstract

A pBAD24 vector containing katE was constructed for use in understanding the effect of katE expression on the UVA-mediated killing of catalase-deficient E. coli. PCR amplified katE was cloned into the pBAD24 expression vector and transformed by electroporation into the catalase-deficient UM2 strain. Screening by colony PCR and digestion of isolated plasmids yielded no positive transformants. Since agarose gel electrophoresis supports successful construction, failure was likely attributable to outnumbering by other pBAD24 containing ligation products or host-construct incompatibility. We propose the metabolic load phenomenon, RecBCD mediated construct instability, and the EcoK restriction system as explanations for host-construct incompatibility.