Nesterenkonia aethiopica sp. nov., an alkaliphilic, moderate halophile isolated from an Ethiopian soda lake

Strain DSM 17733T, isolated from the shore of Lake Abjata in Ethiopia, is a heterotrophic, alkaliphilic, moderately halophilic, Gram-positive, strictly aerobic, non-motile, non-endospore-forming bacterium. The organism grows optimally at 30-37 °C, pH 9 and 3 % (w/ v) NaCl. Analysis of the cell wall showed the presence of murein of the type L-Lys-Gly-L-Glu, variation A4α. The G+C content of the genomic DNA was 69.0 mol%. Sequence analysis of 16S rRNA gene sequence of strain DSM 17733T placed the isolate in the genus Nesterenkonia. DNA-DNA hybridization of DSM 17733T with those organisms with the closest phylogenetic affiliation, i.e. Nesterenkonia halobia, Nesterenkonia lacusekhoensis and Nesterenkonia xinjiangensis, gave relatedness values of 48.5 %, 63.7 % (repetition, 57.2 %) and 35.7 % (repetition, 29.3 %), respectively. On the basis of both phenotypic and phylogenetic criteria and the low levels of DNA-DNA relatedness with the phylogenetically closest species N. xinjiangensis and N. halobia, it is proposed that the isolate be classified in a novel species, Nesterenkonia aethiopica sp. nov. The type strain is DSM 17733T (=CCUG 48939T). © 2006 IUMS.