Terrabacter lapilli sp. nov., an actinomycete isolated from stone

A novel actinomycete, designated strain LR-26^T, was isolated from a small stone collected from an agricultural field in Jeju, Republic of Korea. Cells of the organism were strictly aerobic, Gram-positive, non-motile, short rods. Colonies were bright yellow, circular, smooth and translucent. The organism was characterized chemotaxonomically as having LL-diaminopimelic acid in the cell wall, MK-8(H₄) as major menaquinone, a polar lipid profile including diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, phosphatidylinositol and unknown phospholipids, iso-C_15:0 as the predominant fatty acid and a DNA G+C content of 72.6 mol%. Comparative 16S rRNA gene sequence analysis showed that the organism was related to the genera Intrasporangium, Terracoccus and Terrabacter within the family Intrasporangiaceae. The closest phylogenetic relatives of strain LR-26^T were the type strains of Terrabacter terrae (99.4% 16S rRNA gene sequence similarity), Terrabacter aerolatus (99.3 %) and Terrabacter tumescens (99.3 %). DNA-DNA hybridization experiments showed that strain LR-26T shared low levels of DNA-DNA relatedness with Terrabacter terrae LMG 22921^T (17.6 and 22.8% from reciprocal experiments) and with Terrabacter tumescens IMSNU 21313^T (27.6 and 34.9 %). The phenotypic data and low levels of DNA-DNA relatedness readily distinguished strain LR-26^T from the type strains of recognized species of the genus Terrabacter, and showed that it therefore represents a novel species. The name Terrabacter lapilli sp. nov. is proposed for this novel actinomycete. The type strain is LR-26^T (=JBRI 2002^T =KCTC 19199^T =DSM 18583^T).