Control of <i>Pseudomonas fluorescens</i> in milk by a novel bacteriophage YZU_PF006

Pseudomonas fluorescens is a psychrophilic bacterium that can cause dairy spoilage through the production of heat‐stable enzymes. Bacteriophages are proved as one of the alternatives to control spoilage bacteria in the dairy industry. In this work, a lytic bacteriophage YZU_PF006 against P . fluorescens was isolated from sewage samples in China. Morphology and one‐step growth results indicated that this short‐tailed phage (a tail length of 5 nm and a head diameter of 58 nm) had a high burst size (180 PFU/infected cells) but a relatively short latent period (60 min). This phage can be inactive after pasteurisation and Clean‐In‐Place (CIP) procedures. The genomic sequence showed that phage YZU_PF006 had 47 open reading frames (ORFs) but did not have genes for virulence, lysogeny and antibiotic resistance. Phage YZU_PF006 effectively controlled P. fluorescens growth at 7°C and 28°C in milk, which indicates potential for the control P. fluorescens in the dairy industry.