Coping with inadvertent lysis of Escherichia coli cultures: Strains resistant to lysogeny and infection by the stealthy lysogenic phage Φ80

• Published in: Biotechnology and bioengineering 2019-07, Vol.116 (7), p.1820-1826
• Main Authors: Srinivas, Swaminath, Cronan, John E
• Format: Article
• Language: English
• Subjects: Bacteria; contamination; E coli; Escherichia coli; fhuA; Infections; Lysis; lysogen; Lysogens; Lysogeny; Mutants; Mutation; phage; Phages; Strains (organisms); Temperature requirements; tonA; tonB; Φ80
• ISSN: 0006-3592; 1097-0290
• DOI: 10.1002/bit.26971

Phage Φ80 can infect Escherichia coli in a stealthy manner and persist by forming lysogens. Such Φ80 lysogens are fairly common and often go undetected unless the host is grown at temperatures below 37°C. Since low growth temperatures are required for growing temperature‐sensitive mutants and often preferred for large‐scale applications such as protein production, Φ80‐resistant strains would be useful. We report the construction of E. coli strains that cannot be efficiently lysogenized or infected by bacteriophage Φ80. These strains contain combinations of deletions or mutations in the bacterial attachment site for Φ80 integration and/or deletions in the genes required for phage absorption to the host outer membrane. These strains should help contain and prevent Φ80 infection of E. coli cultures in a laboratory or industrial setting. Srinivas and Cronan construct an Escherichia coli mutants lacking a functional outer membrane receptor (TonB) and a bacterial attachment site (attΦ80) on the genome and demonstrate their resistance to lytic infection and lysogeny by the phage phi80. Phi80 is a bacteriophage that forms stealthy lysogens that are stable at normal growth temperatures but quickly turn lytic at lower temperatures. This mutant strain would help avoid phage‐induced lytic loss of valuable strains in industrial and laboratory settings.