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 Oceanospirillaceae, is well-known for its ability to degrade hydrocarbons and for its close association with algal blooms. However, only a few Oceanospirillaceae-infecting phages have been reported thus far. Here, we report on a novel Oceanospirillum phage, namely, vB_OsaM_PD0307, which has a 44,421 bp linear dsDNA genome and is the first myovirus infecting Oceanospirillaceae. 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 Oceanospimyovirus. Additionally, metagenomic read mapping results have further shown that Oceanospimyovirus 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 Oceanospimyovirus phages.IMPORTANCE Oceanospirillum phage vB_OsaM_PD0307 is the first myovirus found to infect Oceanospirillaceae, 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 Oceanospimyovirus. Oceanospirillum phage vB_OsaM_PD0307 is the first myovirus found to infect Oceanospirillaceae, 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 Oceanospimyovirus.

Automated summary

The marine bacterial family Oceanospirillaceae is well-known for its hydrocarbon degradation ability and its association with algal blooms. This study reports on a novel Oceanospirillum phage, vB_OsaM_PD0307, which is the first myovirus infecting Oceanospirillaceae. Genomic analysis reveals that vB_OsaM_PD0307 is a variant of previously reported phage isolates but shares genomic features with uncultured viral genomes from marine metagenomes. Thus, vB_OsaM_PD0307 is proposed to be classified as a new genus of phages, Oceanospimyovirus. Additionally, metagenomic read mapping results indicate the widespread presence and distinct biogeographic distribution of Oceanospimyovirus species, particularly in polar regions.