Deleya salina sp. nov., a Moderately Halophilic Gram-Negative Bacterium

Deleya sulina sp. nov., which was isolated from hypersaline habitats, is described. Our description is based on 26 strains that exhibit high levels of phenotypic similarity (simple matching coefficient, >74%) and DNA-DNA homology (>71%). The organisms are moderately halophilic gram-negative rods; growth occurs at salt concentrations between 2.5 and 20% (wt/vol) (optimal growth occurs at a salt concentration of 5% [wt/vol]). D. salina is aerobic, nonmotile, and catalase and oxidase positive. The cells accumulate poly-phydroxybutyrate, and the G+C contents of the DNAs range from 60.4 to 64.2 mol%. The type strain is strain FS-11 (= ATCC 49509). Halophilic microorganisms grow optimally at high salt concentrations, and their natural habitats are saline environments, such as seawater, saline lakes, salterns, and saline soils. Most halophilic eubacteria that grow best at NaCl concentrations between 1 and 2 M are referred to as moderate halophiles (12), and this group includes a great variety of morphological and physiological types that belong to very distinct taxonomic groups. In a previous paper we reported that the moderately halophilic, nonmotile, gram-negative , rod-shaped bacteria represent a minor proportion of the microbiota in natural hypersaline habitats (22). We described two groups of aerobic rods (differentiated into two phena, phena A and B, by numerical analysis) that were not phenotypically related to the moderately halophilic valid species. Recently, we described 16 of those moderately halophilic strains (included in phenon B) as Volcaniella eurihalina (21). The purposes of this work were to study in more detail the moderately halophilic strains included in phenon A and to compare them with both halophilic and nonhalophilic gram-negative rods. On the basis of phenotypic and genotypic characteristics, as well as salt requirements, we propose that these isolates should be included in a new species of the genus Deleya, Deleya salina. MATERIALS AND METHODS Bacterial strains and culture media. The strains used in this study were 26 moderately halophilic, gram-negative, nonmotile, rod-shaped bacteria that were isolated from different saline habitats, including saline soils located near Alicante, Spain (15 strains), a solar saltern at Santa Pola, Alicante, Spain (3 strains), inland salty ponds located in La Mala, Granada, Spain (1 strain), an estuary saltern at Huelva, Spain (4 strains), and the Mediterranean Sea off the coast of southeast Spain (3 strains). Descriptions of the saline habitats and their environmental parameters, as well as the methods used for sampling and isolation of the strains, have been given previously (20, 23). The following nonhalophilic and halophilic gram-negative microorganisms were used as reference strains: Acinetobacter calcoaceticus CCM 5581, Alcaligenes faecalis CCM