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 N5BH11T, 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 N5BH11T 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 N5BH11T belonged to the genus Nakamurella and had the highest 16S rRNA gene sequence similarity to Nakamurella flavida DS-52T (98.1 %). The DNA G+C content of strain N5BH11T was 71.6 mol%. The average nucleotide identity values between strain N5BH11T 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 N5BH11T 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(H4) was the predominant menaquinone. The predominant polar lipids were diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylmonomethylethanolamine and unidentified phospholipids. The major fatty acids were iso-C15 : 0, anteiso-C15 : 0, C16 : 0 and C16 : 1ω7c. On the basis of the results of phylogenetic analysis and phenotypic and chemotaxonomic characteristics, strain N5BH11T represents a novel species of the genus Nakamurella, for which the name Nakamurella flava sp. nov. is proposed. The type strain is N5BH11T (=KCTC 49196T=CGMCC 4.7524T).

Amnibacterium flavum sp. nov., a novel endophytic actinobacterium isolated from bark of Nerium indicum Mill.

A Gram-stain-positive, aerobic, short-rod-shaped, non-spore-forming actinobacterial strain, designated M8JJ-5T, was isolated from a surface-sterilized bark of Neriumindicum Mill. collected from Guizhou, China, and investigated by a polyphasic approach to determine its taxonomic position. Strain M8JJ-5T grew optimally without NaCl at 28 °C and at pH 7.0-8.0. Substrate mycelia and aerial mycelia were not formed, and no diffusible pigments were observed on the media tested. Phylogenetic analysis based on the 16S rRNA gene sequence showed that strain M8JJ-5T was most closely related to the type strains of genus Amnibacterium, and shared highest 16S rRNA gene sequence similarity of 97.29 % to Amnibacterium kyonggiense KSL51201-037T. The DNA G+C content of strain M8JJ-5T was 68.6 mol%. The cell-wall peptidoglycan contained l-2,4-diaminobutyric acid and MK-12, MK-11 were the major menaquinones. The predominant polar lipids were diphosphatidylglycerol, phosphatidylglycerol, an unidentified glycolipid, an unidentified phospholipid and an unidentified lipid, while the major fatty acids were iso-C16 : 0, anteiso-C15 : 0 and anteiso-C17 : 0. On the basis of phylogenetic, chemotaxonomic and phenotypic data, strain M8JJ-5T can be characterized to represent a novel species of the genus Amnibacterium, for which the name Amnibacteriumflavum sp. nov. is proposed. The type strain is M8JJ-5T (=KCTC 49089T=CGMCC 1.16390T).