Bacterial weapons: towards an understanding of stochastic tailocin expression

Many bacteria produce phage tail-like bacteriocins, protein particles that are evolutionarily related to the tail structures of bacteriophages. Also known as tailocins, they are released by bacteria undergoing lysis to target and kill their competitors in a kind of microbial altruism on the part of the attacking cell. Despite tailocins first being identified more than 60 years ago, their role in bacterial competition is not fully understood. The expression of tailocins is a stochastic process with a low incidence rate, and while some regulatory pathways are known, there is no clear consensus on how and why a bacterial cell will choose to activate these pathways. In this poster, we demonstrate a synthetic plasmid-based gene circuit that we used to explore the stochastic regulatory behaviour of ECOR38 R-type tailocin expression in microfluidic "mother machines." Mother machines allow continuous observation of a large number of bacteria in a consistent culture environment, enabling the systematic study of the effects of a diverse range of physical and chemical conditions on tailocin expression level and dynamics.