rcsB Does Not Have a Temperature-Dependent Protective Role for Escherichia coli K-12 Against T7 Bacteriophage Lysis

The Regulator of Capsule Synthesis (Rcs) phosphorelay system in Escherichia coli is a complex thermally regulated two component signal transduction system involved in many cellular functions including capsule production. An overproduction of capsule could prevent phage absorption and offer protection to E. coli from bacteriophage lysis. In this study, we aimed to examine the role of rcsB, a response regulator of the Rcs pathway, in protecting E. coli K-12 against T7 bacteriophage lysis by comparing the growth curves of a wild type strain (DH300) and a rcsB knockout strain (DH311) at 25℃, 30℃ and 37℃. Growth measurements showed no differences in lysis rates between the wild type and rcsB knockout strains at 37℃. However, the rcsB KO strain showed delayed T7 bacteriophage lysis compared to the wild type strain at 25℃ and 30℃, with a greater effect observed at 25℃. These data suggest that rcsB may not have a temperature-dependent protective role in Escherichia coli K-12 against T7 bacteriophage lysis.