Discovery of an Abundant Viral Genus in Polar Regions through the Isolation and Genomic Characterization of a New Virus against Oceanospirillaceae

The marine bacterial family , is well-known for its ability to degrade hydrocarbons and for its close association with algal blooms. However, only a few -infecting phages have been reported thus far. Here, we report on a novel phage, namely, vB_OsaM_PD0307, which has a 44,421 bp linear dsDNA genome and is the first myovirus infecting . A genomic analysis demonstrated that vB_OsaM_PD0307 is a variant of current phage isolates from the NCBI data set but that it has similar genomic features to two high-quality, uncultured viral genomes identified from marine metagenomes. Hence, we propose that vB_OsaM_PD0307 can be classified as the type phage of a new genus, designated . Additionally, metagenomic read mapping results have further shown that species are widespread in the global ocean, display distinct biogeographic distributions, and are abundant in polar regions. In summary, our findings expand the current understanding of the genomic characteristics, phylogenetic diversity, and distribution of phages. phage vB_OsaM_PD0307 is the first myovirus found to infect , and it represents a novel abundant viral genus in polar regions. This study provides insights into the genomic, phylogenetic, and ecological characteristics of the new viral genus, namely .