The present study was an effort to look at the effect of quorum sensing molecules which are acyl-homoserine lactones and indole on production and lytic activity of T4 bacteriophage. A predator/prey system model was employed to conduct the experiment. Results obtained during the study showed that acyl-homoserine lactones (AHL), which are essential signaling molecules of quorum sensing in many Gram-negative bacteria, can increase T4 phage production and lysis against Escherichia coli BL21 (DE3) pLysS. In addition, our study showed that indole which can also act as a signaling molecule and is a common diagnostic marker for the identification of E. coli reduced the lysis activity and production of T4 bacteriophage.

Key words: AHL, E coli, Indole, Quorum Sensing, T4 Phage