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

Abstract

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).