Robot-based Automated Isolation and Characterization of a Colicin-producing Escherichia coli-strain with Inhibitory Effect on EPEC

Abstract

In the presented article, isolation of an antimicrobial Escherichia coli (E. coli) strain from municipal wastewater using high-throughput methods by automated liquid handling is described. The effect of the substance, which is mainly present intracellularly, is directed against the enteropathogenic E. coli (EPEC). Subsequent production and purification of the antimicrobial active substance by heat precipitation, ion exchange chromatography, ammonium sulfate precipitation and hydrophobic interaction chromatography allowed its identification as colicin. This finding is supported by the detection of three different colicin genes in the isolated E. coli strain. The assumed colicin could be purified by a factor of 99, resulting in a very pure sample. The developed platform for the identification and purification of antimicrobial substances from environmental samples can be used for further research and may help to overcome the increasing problems with multidrug-resistant microorganisms.