Isolation and characterization of a phage collection against Pseudomonas putida

The environmental bacterium Pseudomonas putida has a wide range of metabolic pathways and thus entails great promise both as cell factories in biotechnological production and for bioremediation approaches to degrade various aromatic pollutants. To thrive in the environment, P. putida has to be able to endure the constant threat posed by bacteriophages. Surprisingly, up until now, only a few phages have been isolated for the common laboratory strain P. putida KT2440, and no phage defence mechanisms have been characterized yet. Here, we introduce a novel C ollection of E nvironmental Pseudomonas putida P hages from Est onia (CEPEST), consisting of 67 dsDNA phages that belong to 22 phage species and nine phage genera. We show that most of the phages in the CEPEST collection are more infectious at lower temperatures, have a narrow host range, and require intact LPS for P. putida infection. Additionally, we demonstrate that cryptic prophages in the P. putida chromosome strongly protect against the infection of many phages, whereas the chromosomal toxin-antitoxin systems play no role in phage defence of P. putida .