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, CA1 and CA2, were isolated from a deep-sea sediment core taken from the Mendeleev Ridge in the western Arctic Ocean. Host bacteria of CA1 and CA2 were affiliated with the genus Pseudoalteromonas based on 16S rRNA gene sequences. The Pseudoalteromonas bacteriophages of CA1 and CA2 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 Myoviridae. 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 CA1 and CA2 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).