Comparative omics and trait analyses of marine Pseudoalteromonas phages advance the phage OTU concept

摘要: Viruses influence the ecology and evolutionary trajectory of microbial communities. Yet our understanding their roles in ecosystems is limited by paucity model systems available for hypothesis generation testing. Further, virology lack a broadly accepted conceptual framework to classify viral diversity into ecologically cohesive units. Here, we introduce genomes, structural proteomes, quantitative host range data eight Pseudoalteromonas phages isolated from Helgoland (North Sea, Germany) use these advance genome-based operational taxonomic unit (OTU) definition. These viruses represent five new genera inform 498 unaffiliated or unannotated protein clusters (PCs) global virus metagenomes. In comparison previously sequenced phage isolates (n = 7) predicted prophages 31), are unique. They share genus with only one other isolate, podophage RIO-1 (East South Korea) two prophages. Mass-spectrometry purified particles identified 12-20 proteins per phage. When combined 3-D predictions, led functional characterization unidentified major capsid proteins. Protein predictions revealed mechanisms hijacking metabolism resources. they uncovered hybrid sipho-myovirus that encodes genes Mu-like infection rarely described ocean systems. Finally, used evaluate recently introduced definition populations requires members same population have >95% average nucleotide identity across at least 80% genes. Using physiological traits genomics, proposed OTU captures evolutionarily distinct this trait-based framework, sensitive hosts considered niches, while ranges efficiencies tracked as traits. Quantitative assays conserved within OTUs break down between OTUs, suggesting defined units capture niche fitness differentiation. Together analyses provide foundation system-based testing will improve marine copiotrophs, well phage-host interactions on aggregates where thrive.