Morphological characteristics and complete sequences of two cold-active Pseudoalteromonas phages

Abstract

Cold-active bacteriophages are generally defined as bacterial viruses that are capable of infection and production at low temperature (≤ 4°C). Several studies of cold-active bacteriophages isolated from aquatic environments have been reported. However, characteristics of cold-active bacteriophage-host systems in deep-sea sediments are still poorly understood, despite high viral abundance maintain in persistently low temperature. Two bacteriophages, φCA1 and φCA2, were isolated from a deep-sea sediment core taken from the Mendeleev Ridge in the western Arctic Ocean. Host bacteria of φCA1 and φCA2 were affiliated with the genus <em>Pseudoalteromonas</em> based on 16S rRNA gene sequences. The <em>Pseudoalteromonas</em> bacteriophages of φCA1 and φCA2 turned out to exhibit successive propagations at low temperature of 1°C, indicating that they are cold-active ones. Each phage has a contractile tail, which is a morphological feature of the family <em>Myoviridae</em>. To find genomic characteristics of the cold-active phages, a complete genome sequence of each phage was obtained by Illumina MiSeq sequencing technology. The genome sizes of φCA1 and φCA2 were 36,825 bp and 36,989 bp, respectively, with an identical G+C content of 43.1 mol%. Details of genomic content of the cold-active phages and their relatedness with other phages will be provided in a poster presentation. This work was supported by a grant of Korea Polar Research Institute (PE16062).