Engineering laboratory/factory-specific phage-resistant strains of Escherichia coli by mutagenesis and screening.

The Escherichia coli (E. coli) has been widely employed in biotechnology industry and academia. However, the bioproduct manufacturing driven by E. coli is prone to the phage contamination. Good laboratory/factory hygiene may decrease but not avoid completely the chances of the phage contamination. The present study aims to resolve this problem by engineering laboratory/factory-specific phage-resistant E. coli strains. By adding a laboratory or factory derived phage into the atmospheric and room temperature plasma mutagenized E. coli, a phage-resistant strain could be generated. Interestingly, the resistant strain exhibited cross-resistance to unencountered phages. When operating the resistant strain in a polluted environment, the phage contamination was largely prevented. There was no significant difference in heterogeneous protein production between the parental strain and the phage-resistant strain. Importantly, it requires only one day to generate the phage-resistant strain. This practical method for engineering laboratory/factory-specific phage-resistant strains may have great potential in resuming E. coli operation in laboratories and factories during phage contamination outbreaks.