Curvibacter phage TJ1 strain:AEP1-3 Genome sequencing. Curvibacter phage TJ1 strain:AEP1-3

Many multicellular organisms are closely associated with a specific bacterial community and therefore considered “metaorganisms”. Controlling the bacterial community composition is essential for the stability and function of metaorganisms, but the factors contributing to the maintenance of host specific bacterial colonization are poorly understood. Here we demonstrate that in Hydra the most dominant bacterial colonizer Curvibacter sp. is associated with an intact prophage which can be reactivated by different environmental stressors both in vitro and in vivo. Differences in the reactivation capacity of Curvibacter phage TJ1 in culture (in vitro) and on Hydra (in vivo) imply that the habitat of the prokaryotic host is an important factor for phage inducibility. Moreover, we show that phage TJ1 features a broad host range against other bacterial colonizer and is directly capable to influence bacterial colonization on Hydra. From these results we conclude that phage TJ1 plays an important part in shaping and maintaining Hydra´s bacterial community.