Biological characterization and genomic profiling of a novel providencia phage isolated from farm effluents

We successfully isolated a Providencia strain from farm effluents. Using this strain as the host, we obtained bacteriophage A06. A comprehensive set of experiments were carried out, including systematic biophysical characterization and in - depth genomic analysis. The double - layer agar plaque assay was used to determine the multiplicity of infection (MOI), construct the one - step growth curve, evaluate temperature and pH stability, and assess the in vitro antibacterial activity of bacteriophage A06. Its lysis efficiency was quantified by the plaque counting method. Through whole - genome sequencing, functional annotation, and comparative genomics analysis, we comprehensively characterized its biological features and clarified its taxonomic position. This study revealed that bacteriophage A06 has a circular DNA genome with 58 open reading frames (ORFs). The optimal MOI for bacteriophage A06 was determined to be 100. The one - step growth curve showed that the latent period of bacteriophage A06 was 40 minutes, and the lysis period ranged from 40 to 90 minutes. Notably, bacteriophage A06 exhibited remarkable thermal stability and pH tolerance. Genomic analysis firmly established that bacteriophage A06 represents a novel species within the genus Kakivirus of the family Autographiviridae .