A role for phospholipid hydrolysis in the lysis of Escherichia coli infected with bacteriophage T4

Abstract

During the infection of Escherichia coli strain B with bacteriophage T4B, the composition of the cellular lipid changes markedly. Beginning 10–13 minutes after infection, the amount of free fatty acid in the cell increases greatly. This increase continues until complete lysis of the infected culture has occurred and results in 10–15% of the cellular lipid being converted to free fatty acid (a 50-fold increase over the level found in uninfected cells). It was shown that this free fatty acid is produced by the breakdown of the cellular phospholipid, not by the release of cell wall fatty acid or by the de novo synthesis of fatty acid. The production of free fatty acid appears to be induced by the infecting phage, as protein synthesis must occur after infection for this production to occur. The production of fatty acid is inhibited by puromycin (but not chloramphenicol) added early in the latent period. The production of free fatty acid (or the concomitant loss of phospholipid) is thought to be involved in the lysis of the infected cell, as this production is transiently inhibited by lysis inhibition caused by superinfection.