Asticcacaulis tiandongensis sp. nov., a new member of the genus Asticcacaulis, isolated from a cave soil sample

Abstract

A Gram-stain negative, aerobic, motile and rod-shaped bacterium, designated strain 3.1105^T, was isolated from a karst district soil sample collected from Tiandong cave, Guizhou province, south-west PR China. The isolate grew at 10-40 °C and pH 5.0-8.0 and tolerated up to 1 % NaCl (w/v) on R2A medium, with optimal growth at 25-30 °C, pH 7.0 and 0 % NaCl (w/v). Cells showed oxidase-positive and catalase-positive reactions. The respiratory quinone was Q-10. The predominant cellular fatty acids contained C_{18 : 1}ω7c 11-methyl, summed feature 8 (C_{18 : 1}ω7c or C_{18 : 1}ω6c), C_{16 : 0} and C_{17 : 0}. The major polar lipids were phosphatidylglycerol and monoglycosyldiglycerides. The genomic DNA G+C content was 56.0 mol%. Phylogenetic analysis based on 16S rRNA gene sequences indicated that 3.1105^T should be affiliated to the genus Asticcacaulis and showed highest 16S rRNA gene sequence similarity values with Asticcacaulis excentricus CB 48^T (96.0 %), Asticcacaulis endophyticus ZFGT-14^T (95.3 %) and lower than 95.3 % similarity to other species of the genus Asticcacaulis. The polyphasic taxonomic characteristics indicated that strain 3.1105^T represents a novel species of the genus Asticcacaulis, for which the name Asticcacaulis tiandongensis sp. nov., (type strain 3.1105^T=KCTC 62978^T=CCTCC AB 2018268^T) is proposed.

Keywords: Asticcacaulis tiandongensis sp.nov; karst district; polyphasic taxonomy.