Prauseria antiqua gen. nov., sp. nov., a New Member of the Actinomycete Family Jiangellaceae

Abstract A Gram-stain-positive, aerobic actinomycete, strain VKM Ac-2616T, with highly branched fragmenting vegetative and aerial hyphae, was isolated from soil sampled from a food jug during archaeological excavations of ancient burial mounds in the Republic of Kalmykia, Russia, in 2003. Phylogenetic analysis based on 16S rRNA gene sequences showed that the target strain clustered with the family Jiangellaceae, showing the highest sequence similarity to the type strains of Haloactinopolyspora alkaliphila (97.5%) and Jiangella aurantiaca (97.4%), with 96.9, 96.8, and 95.7% similarities towards the type strains of type species of the genera Haloactinopolyspora, Jiangella, and Phytoactinopolyspora, respectively. The dDDH and ANI values between VKM Ac-2616ᵀ and other Jiangellaceae species were well below 70 and 95%, respectively, the generally accepted thresholds for species delineation. The AAI values of Ac-2616ᵀ with regard to the described Jiangellaceae species were 62.2–65.5%, which are within the AAI cutoff range (60–85%) for genus delimitation and lower than 68.8%, the maximum value between type species of the known genera in this family. The cell wall contained LL-diaminopimelic acid, rhamnose, and an unidentified aminosugar. The major menaquinone was MK-9(H4), the fatty acids were dominated by anteiso-C15:0 and iso-C15:0, the polar lipid profile included diphosphatidylglycerol, phosphatidylglycerol, phosphatidylinositol, acylphosphatidylglycerol-like lipid, and a number of unidentified phospholipids and phosphoglycolipids. The genome size of the strain was approximately 5.6 Mbp, and the DNA G+C content was 70.15%. Based on the data obtained, a new genus and a new species, Prauseria antiqua gen. nov., sp. nov., with the type strain L44385T (= VKM Ac-2616T) are proposed.