Gordonia caeni sp. nov., isolated from sludge of a sewage disposal plant

A Gram-stain-positive, strictly aerobic, short-rod-shaped, non-motile strain (designated MJ32^T) was isolated from a sludge sample of the Daejeon sewage disposal plant in South Korea. A polyphasic approach was applied to study the taxonomic position of strain MJ32^T. Strain MJ32^T showed highest 16S rRNA gene sequence similarity to Gordonia hirsuta DSM 44140^T (98.1 %) and Gordonia hydrophobica DSM 44015^T (97.0 %); levels of sequence similarity to the type strains of other recognized Gordonia species were less than 97.0 %. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain MJ32^T belonged to the clade formed by members of the genus Gordonia in the family Gordoniaceae. The G+C content of the genomic DNA of strain MJ32^T was 69.2 mol%. Chemotaxonomically, strain MJ32^T showed features typical of the genus Gordonia. The predominant respiratory quinone was MK-9(H₂), the mycolic acids present had C₅₆–C₆₀ carbon atoms, and the major fatty acids were C_16 : 0 (34.6 %), tuberculostearic acid (21.8 %), C_16 : 1ω7c (19.5 %) and C_18 : 1ω9c (12.7 %). The peptidoglycan type was based on meso-2,6-diaminopimelic acid as the diagnostic diamino acid with glycolated sugars. On the basis of phylogenetic inference, fatty acid profile and other phenotypic properties, strain MJ32^T is considered to represent a novel species of the genus Gordonia, for which the name Gordonia caeni sp. nov. is proposed. The type strain is MJ32^T ( = KCTC 19771^T = JCM 16923^T).