The First Pseudomonas Phage vB_PseuGesM_254 Active against Proteolytic Pseudomonas gessardii Strains

Bacteria of the <i>Pseudomonas</i> genus, including the <i>Pseudomonas gessardii</i> subgroup, play an important role in the environmental microbial communities. Psychrotolerant isolates of <i>P. gessardii</i> can produce thermostable proteases and lipases. When contaminating refrigerated raw milk, these bacteria spoil it by producing enzymes resistant to pasteurization. One possible way to prevent spoilage of raw milk is to use <i>Pseudomonas</i> lytic phages specific to undesirable <i>P. gessardii</i> isolates. The first phage, <i>Pseudomonas</i> vB_PseuGesM_254, was isolated and characterized, which is active against several proteolytic <i>P. gessardii</i> strains. This lytic myophage can infect and lyse its host strain at 24 °C and at low temperature (8 °C); so, it has the potential to prevent contamination of raw milk. The vB_PseuGesM_254 genome, 95,072 bp, shows a low level of intergenomic similarity with the genomes of known phages. Comparative proteomic ViPTree analysis indicated that vB_PseuGesM_254 is associated with a large group of <i>Pseudomonas</i> phages that are members of the <i>Skurskavirinae</i> and <i>Gorskivirinae</i> subfamilies and the <i>Nankokuvirus</i> genus. The alignment constructed using ViPTree shows that the vB_PseuGesM_254 genome has a large inversion between ~53,100 and ~70,700 bp, which is possibly a distinctive feature of a new taxonomic unit within this large group of <i>Pseudomonas</i> phages.