Jatrophihabitans huperziae sp. nov., an endophytic actinobacterium isolated from surface-sterilized tissue of the medicinal plant Huperzia serrata (Thunb.)

A novel endophytic actinobacterium, designated strain CPCC 204076T, was isolated from surface-sterilized tissue of the medicinal plant Huperzia serrata (Thunb.) collected from Sichuan Province, south-west China. The taxonomic position of the isolate was investigated by a polyphasic approach. The strainwas aerobic, Gram-stain-positive, non-motile, non-spore-forming and rod-shaped. Growth was observed at 10-37 °C, at pH 5.0-10.0 and with 0-3.0 % (w/v) NaCl. The polar lipid fraction consisted of diphosphatidylglycerol, a phospholipid, an aminolipid, a glycolipid, an aminophospholipid and phosphatidylinositol. The cell wall contained meso-diaminopimelic acid as the diagnostic diamino acid and the peptidoglycan was of type A4γ. The menaquinone system consisted of MK-9(H4) and MK-8(H4). The major cellular fatty acids (>10 %) were iso-C16 : 0 and anteiso-C17 : 0. The genomic DNA G+C content of strain CPCC 204076T was found to be 71.9 mol%. Phylogenetic analysis based on 16S rRNA gene sequences revealed that CPCC 204076T belongs to the genus Jatrophihabitans with highest sequence similarity to Jatrophihabitans endophyticus DSM 45627T (96.5 %), Jatrophihabitans soli DSM 45908T (96.5 %) and Jatrophihabitans fulvus JCM 30448T (96.1 %), and much lower similarities (<95.0 %) to other available 16S rRNA gene sequences from validly described pure cultures. However, DNA-DNA hybridyzation values between strain CPCC 204076T and the three recognized Jatrophihabitans species were 31±3.1 % (J. endophyticus DSM 45627T), 33±2.9 % (J. soli DSM 45908T) and 37±1.7 % (J. fulvus JCM 30448T), which were all far below the recommended cut-off value of 70 %. The phenotypic and genomic characteristics distinctly indicated that strain CPCC 204076T represents a novel species of the genus Jatrophihabitans, for which the name Jatrophihabitans huperziae sp. nov. is proposed. The type strain is CPCC 204076T (I13A-01604) (=DSM 46866T=NBRC 110718T).