Novel Bacillus-Infecting Bacteriophage B13—The Founding Member of the Proposed New Genus Bunatrivirus

In this work, we describe a novel temperate bacteriophage, Bacillus phage B13. Bacillus-infecting phages are widespread and abundant, though often overlooked including because of their temperate lifestyle. B13 was isolated from its bacterial host via mitomycin C induction. Its host range was determined, and its pH and thermal stability were evaluated. The whole genome of B13 was sequenced and annotated. The genome is 36,864 bp long and contains 53 genes. The tail genes of B13 suggest that the phage has a siphovirus morphotype. It was found both in vitro and in silico that the phage uses the 3′-cos DNA packaging strategy, and the phage genome termini were located. Comparative analyses revealed that B13 has no close relatives and should therefore be assigned to a new viral genus, for which we propose the name Bunatrivirus.