Abstract

A thermo-acidophilic bacterium, designated strain ACK006T, was isolated from the soil of a hot spring at Tengchong in China. Cells were Gram-staining-positive, motile, catalasepositive and oxidase-negative, spore-forming rods. The isolate grew aerobically at 30–50°C (optimum at 45°C), pH 2.0–6.0 (optimum pH 3.2) and 0–5.0% (w/v) NaCl (optimum 1% NaCl). Phylogenetic analyses based on 16S rRNA gene sequences indicated that strain ACK006T belongs to the genus Alicyclobacillus with the sequence similarity of 92.3, 92.4, 92.5, and 92.8% to Alicyclobacillus cycloheptanicus SCHT, Alicyclobacillus ferrooxydans TC-34T, Alicyclobacillus contaminans 3-A191T and Alicyclobacillus disulfidooxidans SD-11T, respectively. Similarity to other species of the genus Alicyclobacillus was 90.3–92.8% and similarity to species of the genus Tumebacillus was 85.9–87.8%. The genomic DNA G+C content was 53.7 mol%. The predominant menaquinone was MK-7. Major fatty acids were ω-cycloheptane C18:0, iso-C17:0 and anteiso-C17:0. The cell-wall peptidoglycan was the A1γ type; containing meso-diaminopimelic acid as the diagnostic diamino acid. On the basis of polyphasic analysis from this study, strain ACK006T represents a novel species of the genus Alicyclobacillus for which the name Alicyclobacillus tengchongensis sp. nov. is proposed. The type strain is ACK006T (=KCTC 33022T =DSM 25924T).

• Keywords: Alicyclobacillus tengchongensis sp. nov.; acidophilic bacterium; taxonomy