Segeticoccus rhizosphaerae gen. nov., sp. nov., an actinobacterium isolated from soil of a farming field

A Gram-stain-positive actinobacterial strain, designated YJ01T, was isolated from a spinach farming field soil at Shinan in Korea. Strain YJ01T was aerobic, non-motile, non-spore-forming cocci with diameters of 1.5–1.9 µm, and was able to grow at 10–37 °C (optimum, 28–30 °C), at pH 4.5–9.0 (optimum, pH 7.0–8.0) and at salinities of 0–7.5 % (w/v) NaCl (optimum, 1.0 % NaCl). Sequence similarities of the 16S rRNA gene of strain YJ01T with closely related relatives were in the range 96.2–92.8 %, and the results of phylogenomic analysis indicated that strain YJ01T was clearly separated from species of genera in the family Intrasporangiaceae showing average nucleotide identity values of 84.2–83.4 %. The predominant isoprenoid quinone was identified as MK-8(H4) and the major fatty acids were iso-C15 : 0, iso-C16 :1 h, iso-C16 : 0 and anteiso-C17 : 1ω9c. The diagnostic diamino acid of the peptidoglycan was ornithine, and the interpeptide bridge was l-Orn–Gly2–d-Glu. The major polar lipids were identified as diphosphatidylglycerol, phosphatidylglycerol, phosphatidylserine, an unidentified phosphatidylglycolipid, two unidentified phosphoaminolipids and an unidentified phosphoglycoaminolipid. The G+C content of the genome was 70.1 mol%. On the basis of phenotypic and chemotaxonomic properties and phylogenetic and phylogenomic analyses using 16S rRNA gene sequences and whole-genome sequences, strain YJ01T is considered to represent a novel species of a new genus in the family Intrasporangiaceae , for which the name Segeticoccus rhizosphaerae gen. nov. sp. nov. is proposed. The type strain of Segeticoccus rhizosphaerae is YJ01T (=KACC 19547T=NBRC 113173T).