Mycobacterium aquiterrae sp. nov., a rapidly growing bacterium isolated from groundwater

A strain representing a rapidly growing, Gram-stain-positive, aerobic, rod-shaped, non-motile, non-sporulating and non-pigmented species of the genus Mycobacterium , designated strain S-I-6T, was isolated from groundwater at Daejeon in Korea. The strain grew at temperatures between 10 and 37 °C (optimal growth at 25 °C), between pH 4.0 and 9.0 (optimal growth at pH 7.0) and at salinities of 0–5 % (w/v) NaCl, growing optimally with 2 % (w/v) NaCl. Phylogenetic analyses based on multilocus sequence analysis of the 16S rRNAgene, hsp65, rpoB and the 16S–23S internal transcribed spacer indicated that strain S-I-6T belonged to the rapidly growing mycobacteria, being most closely related to Mycobacterium sphagni . On the basis of polyphasic taxonomic analysis, the bacterial strain was distinguished from its phylogenetic neighbours by chemotaxonomic properties and other biochemical characteristics. DNA–DNA relatedness among strain S-I-6T and the closest phylogenetic neighbour strongly support the proposal that this strain represents a novel species within the genus Mycobacterium , for which the name Mycobacterium aquiterrae sp. nov. is proposed. The type strain is S-I-6T (=KACC 17600T=NBRC 109805T=NCAIM B 02535T).