Naumannella huperziae sp. nov., an endophytic actinobacterium isolated from Huperzia serrata (Thunb.)

An endophytic, short rod-shaped, non-motile and non-spore-forming actinobacterium, designated strain CPCC 204135T, was isolated from a surface-sterilized medicinal plant, Huperzia serrata (Thunb.), collected from Sichuan Province, south-west China. Strain CPCC 204135T was observed to grow at temperatures between 20 and 37 °C (optimum, 28-32 °C), at pH 6.0-9.0 (optimum, pH 7.0-8.0) and in the presence of 0-9.0 % (w/v) NaCl (optimum, 0-3 %). Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain CPCC 204135T belonged to the genus Naumannella, showing the highest level of 16S rRNA gene sequence similarity with Naumannella halotolerans DSM 24323T (97.2 %), the only species of the genus Naumannella in the family Propionibacteriaceaewith avalidly published name. The DNA-DNA hybridization value between strain CPCC 204135T and N. halotolerans DSM 24323T was 20.1±1.8 %, which is far below the accepted 70 % threshold for species delineation. The cell-wall hydrolysates contained ll-diaminopimelic acid, alanine, glycine and glutamic acid, with the peptidoglycan type of A3γ. Diphosphatidylglycerol, phosphatidylglycerol, an unidentified phospholipid, one unidentified aminolipid, one unidentified polar lipid and several kinds of glycolipids were detected in the polar lipids profile. MK-9(H4) was identified as the predominant menaquinone. The major cellular fatty acids (>10 %) were anteiso-C15 : 0 and iso-C16 : 0. The G+C content of the genomic DNA of strain CPCC 204135T was determined to be 71.8 mol%. On the basis of phylogenetic analysis, and phenotypic and chemotaxonomic characteristics, we concluded that strain CPCC 204135T represents a novel species of the genus Naumannella, for which the name Naumannella huperziae sp. nov. is proposed, with strain CPCC 204135T (=DSM 101717T=NBRC 111773T) as the type strain.