Phylogenomic and phenotypic investigations of Terrisphaera buseokensis gen. nov., sp. nov., a verrucomicrobium isolated from riverside soil.

A comprehensive polyphasic investigation was conducted on a novel verrucomicrobium, designated as 23ND18S-11T, isolated from riverside soil in South Korea. Strain 23ND18S-11T was coccoid-shaped that occur predominantly in pairs, Gram-stain-negative, obligately aerobic, pale yellow-pigmented, and non-motile. It grew at 0-1.0% NaCl (w/v), pH 6.0-9.5, and 20-30 °C. Strain 23ND18S-11T was assigned to the family Opitutaceae in the phylum Verrucomicrobiota, showing the highest 16S rRNA gene sequence similarity (95.0%) to Horticoccus luteus KSB-15T. MK-7 was the sole quinone and the predominant (> 10%) fatty acids were anteiso-C15:0 and C16:0. The polar lipids were composed of phosphatidylethanolamine, two unidentified aminophospholipids, an unidentified glycolipid, four unidentified glycophospholipids, and an unidentified lipid. The genome size of strain 23ND18S-11T was 7.2 Mb with a genomic DNA G + C content of 65.5%. The AAI and POCP values between the genomes of strain 23ND18S-11T and its closely related taxa in the family Opitutaceae were 63.7-67.6% and 31.8-48.6%, respectively. The dDDH value of strain 23ND18S-11T with H. luteus KSB-15T was 19.7%. The genome of strain 23ND18S-11T was found to contain a cluster of genes (oleA, oleB, oleC, and oleD) involved in alkene synthesis as well as several genes that encode industrially significant enzymes involved in the degradation of bio-macromolecules. Consequently, the strain 23ND18S-11T should be identified and classified as a novel genus and species of the family Opitutaceae, for which the name Terrisphaera buseokensis gen. nov., sp. nov. is proposed. The type strain is 23ND18S-11T (= KCCM 90593T = FBCC-B19162T = NBRC 117123T).