RESUMEN
A novel strain of the genus Promicromonospora, designated PT9T, was recovered from irradiated roots of the xerophyte Panicum turgidum collected from the Ksar Ghilane oasis in southern Tunisia. Strain PT9T is aerobic, non-spore-forming, Gram- positive actinomycete that produces branched hyphae and forms white to yellowish-white colonies. Chemotaxonomic features, including fatty acids, whole cell sugars and polar lipid profiles, support the assignment of PT9T to the genus Promicromonospora. The genomic relatedness indexes based on DNA-DNA hybridization and average nucleotide identity values revealed a significant genomic divergence between strain PT9T and all sequenced type strains of the taxon. Phylogenomic analysis showed that isolate PT9T was most closely related to Promicromonospora soli CGMCC 4.7398T. Phenotypic and phylogenomic analyses suggest that isolate PT9T represents a novel species of the genus Promicromonospora, for which the name Promicromonospora panici sp. nov. is proposed. The type strain is PT9T (LMG 31103T = DSM 108613T).The isolate PT9T is an ionizing-radiation-resistant actinobacterium (D10 value = 2.6 kGy), with resistance to desiccation and hydrogen peroxide. The complete genome sequence of PT9T consists of 6,582,650 bps with 71.2% G+C content and 6291 protein-coding sequences. This genome will help to decipher the microbial genetic bases for ionizing-radiation resistance mechanisms including the response to oxidative stress.