Sz-Jie Wu

Halomonas beimenensis sp. nov., isolated from an abandoned saltern

A Gram-staining negative, motile, non-spore-forming, short rod-shaped (0.8-1.5 × 1.5-2.0 µm), halophilic bacterium, designated strain NTU-107(T), was isolated from brine samples collected from the abandoned Beimen saltern in southern Taiwan. The novel strain grew with 0-15% (w/v) NaCl (optimum between 5% and 10%), at 15-55 °C (optimum 40 °C) and at pH 5.5-9.5 (optimum pH 7.5). The major cellular fatty acids were C(18:1)ω7c, C(16:0) and C(19:0 )cyclo ω8c, the genomic DNA G+C content was 66.5 mol%, and the predominant ubiquinone was Q-9. The major polar lipids included phosphatidylglycerol, diphosphatidylglycerol and phosphatidylethanolamine. In a phylogenetic analysis based on 16S rRNA gene sequences, strain NTU-107(T) clustered with members of the genus Halomonas. In hybridization experiments, however, the levels of DNA-DNA relatedness between strain NTU-107(T) and the type strains of its closest phylogenetic neighbours (Halomonas koreensis, H. organivorans and H. ventosae) were all found to be less than 40 %. Based on the phenotypic, chemotaxonomic and genetic data, strain NTU-107(T) represents a novel species within the genus Halomonas, for which the name Halomonas beimenensis sp. nov. is proposed. The type strain is NTU-107(T) ( = BCRC 17999(T) = KCTC 22876(T) = JCM 16084(T)).