Isolation and characterization of the new Streptomyces phages Kamino, Geonosis, Abafar and Scarif infecting a broad range of host species

Abstract

Streptomyces, a multifaceted genus of soil-dwelling bacteria within the phylum Actinobacteria, features intricate phage-host interactions shaped by its complex life cycle and the synthesis of a diverse array of specialized metabolites. Here, we describe the isolation and characterization of four novel Streptomyces phages infecting a variety of different host species. While phage Kamino, isolated on Streptomyces kasugaensis, is predicted to be temperate and encodes a serine integrase in its genome, phages Geonosis (isolated on S. griseus) and phages Abafar and Scarif, isolated on S. albidoflavus, are virulent phages. Phages Kamino and Geonosis were shown to amplify well in liquid culture leading to a pronounced culture collapse already at low titres. Determination of the host range by testing >40 different Streptomyces species identified phages Kamino, Abafar and Scarif as broad host range phages, with Kamino showing productive infections on 15 different species. Isolated phages were further tested regarding their sensitivity to antiphage molecules. Here, the strongest effects were observed for the DNA-intercalating molecule daunorubicin. Overall, the phages described in this study expand the publicly available portfolio of phages infecting Streptomyces and will be instrumental for advancing the mechanistic understanding of the intricate antiviral strategies employed by these multicellular bacteria.