Systematic strategies for developing phage resistant Escherichia coli strains

Abstract

<jats:title>Abstract</jats:title><jats:p>Phages are regarded as powerful antagonists of bacteria, especially in industrial fermentation processes involving bacteria. While bacteria have developed various defense mechanisms, most of which are effective against a narrow range of phages and consequently exert limited protection from phage infection. Here, we report a strategy for developing phage-resistant <jats:italic>Escherichia coli</jats:italic> strains through the simultaneous genomic integration of a DNA phosphorothioation-based Ssp defense module and mutations of components essential for the phage life cycle. The engineered <jats:italic>E. coli</jats:italic> strains show strong resistance against diverse phages tested without affecting cell growth. Additionally, the resultant engineered phage-resistant strains maintain the capabilities of producing example recombinant proteins, D-amino acid oxidase and coronavirus-encoded nonstructural protein nsp8, even under high levels of phage cocktail challenge. The strategy reported here will be useful for developing engineered <jats:italic>E. coli</jats:italic> strains with improved phage resistance for various industrial fermentation processes for producing recombinant proteins and chemicals of interest.</jats:p>