Nakamurella flava sp. nov., a novel endophytic actinobacterium isolated from Mentha haplocalyx Briq.

A Gram-stain-positive, aerobic, coccus-shaped, non-spore-forming actinobacterium, designated strain N5BH11 T , was isolated from a surface-sterilized sample of Mentha haplocalyx Briq. collected from Guizhou, PR China and tested by a polyphasic approach to determine its taxonomic position. Strain N5BH11 T grew optimally at 30 °C, pH 6.0–7.0. Substrate mycelia and aerial mycelia were not formed, and no diffusible pigments were observed on the media tested. Phylogenetic analysis based on 16S rRNA gene sequence suggested that strain N5BH11 T belonged to the genus Nakamurella and had the highest 16S rRNA gene sequence similarity to Nakamurella flavida DS-52 T (98.1 %). The DNA G + C content of strain N5BH11 T was 71.6 mol%. The average nucleotide identity values between strain N5BH11 T and the type strains of Nakamurella panacisegetis , Nakamurella multipartita and Nakamurella lactea were 74.0, 76.5 and 73.6 %, respectively. The estimated DDH values between strain N5BH11 T and the type strains of N. panacisegetis , N. multipartita and N. lactea were 20.3%, 21.4 and 20.2 %, respectively. The cell-wall peptidoglycan contained meso -diaminopimelic acid, and MK-8(H 4 ) was the predominant menaquinone. The predominant polar lipids were diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylmonomethylethanolamine and unidentified phospholipids. The major fatty acids were iso-C 15 : 0 , anteiso-C 15 : 0 , C 16 : 0 and C 16 : 1 ω7 c . On the basis of the results of phylogenetic analysis and phenotypic and chemotaxonomic characteristics, strain N5BH11 T represents a novel species of the genus Nakamurella , for which the name Nakamurella flava sp. nov. is proposed. The type strain is N5BH11 T (=KCTC 49196 T =CGMCC 4.7524 T ).