The First Cbk-Like Phage Infecting Erythrobacter , Representing a Novel Siphoviral Genus

• Published in: Frontiers in microbiology 2022-05, Vol.13, p.861793
• Main Authors: Li, Xuejing, Guo, Ruizhe, Zou, Xiao, Yao, Yanyan, Lu, Longfei
• Format: Article
• Language: English
• Subjects: Cbk-like phage; Erythrobacter; genomic analysis; Microbiology; novel genus; phylogenetic analysis
• ISSN: 1664-302X; 1664-302X
• DOI: 10.3389/fmicb.2022.861793

is an important and widespread bacterial genus in the ocean. However, our knowledge about their phages is still rare. Here, a novel lytic phage vB_EliS-L02, infecting DSM 8509, was isolated and purified from Sanggou Bay seawater, China. Morphological observation revealed that the phage belonged to Cbk-like siphovirus, with a long prolate head and a long tail. The host range test showed that phage vB_EliS-L02 could only infect a few strains of , demonstrating its potential narrow-host range. The genome size of vB_EliS-L02 was 150,063 bp with a G+C content of 59.43%, encoding 231 putative open reading frames (ORFs), but only 47 were predicted to be functional domains. Fourteen auxiliary metabolic genes were identified, including phoH that may confer vB_EliS-L02 the advantage of regulating phosphate uptake and metabolism under a phosphate-limiting condition. Genomic and phylogenetic analyses indicated that vB_EliS-L02 was most closely related to the genus with low similarity (shared genes < 30%, and average nucleotide sequence identity < 70%), distantly from other reported phages, and could be grouped into a novel viral genus cluster, in this study as . Meanwhile, the genus and stand out from other siphoviral genera and could represent a novel subfamily within , named -II. Being a representative of an understudied viral group with manifold adaptations to the host, phage vB_EliS-L02 could improve our understanding of the virus-host interactions and provide reference information for viral metagenomic analysis in the ocean.