Asticcacaulis endophyticus sp. nov., a prosthecate bacterium isolated from the root of Geum aleppicum

Abstract

A strictly aerobic, light-yellow-coloured, stalked bacterium, designated strain ZFGT-14(T), was isolated from the root of Geum aleppicum Jacq. collected from Taibai Mountain in Shaanxi province, north-west China, and was subjected to a taxonomic study using a polyphasic approach. This novel isolate grew at 7-33 °C (optimum 25-28 °C) and pH 6.0-10.0 (optimum pH 7.0-8.0). Flexirubin-type pigments were not produced. Cells were Gram-stain-negative, rod-shaped and motile with a single polar flagellum. The predominant respiratory quinone was Q-10. The major cellular fatty acids were summed feature 8 (comprising C18 : 1ω7c/C18 : 1ω6c), C16 : 0, C19 : 0 cyclo ω8c and summed feature 3 (comprising C16 : 1ω7c and/or C16 : 1ω6c) and the major polar lipids were phosphatidylglycerol and glycolipids. The DNA G+C content was 57.8 mol%. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain ZFGT-14(T) was most closely related to the genus Asticcacaulis and had low sequence similarity (95.0-95.9 %) with all species with validly published names within the genus Asticcacaulis. Based on the phenotypic, phylogenetic and genotypic data, strain ZFGT-14(T) is considered to represent a novel species of the genus Asticcacaulis, for which the name Asticcacaulis endophyticus sp. nov. is proposed. The type strain is ZFGT-14(T) ( = CCTCC AB 2013012(T) = KCTC 32296(T) = LMG 27605(T)).