Halomonas maura sp nov., a novel moderately halophilic, exopolysaccharide-producing bacterium

Four moderately halophilic, exopolysaccharide-producing bacterial strains isolated from soil samples collected from a saltern at Asilah (Morocco) are reported. These four strains were initially considered to belong to the genus Halomonas. Their DNA G+C contents varied between 62.2 and 64.1 mol%. DNA-DNA hybridization revealed a considerable degree of DNA-DNA similarity amongst all four strains (75.5-80.8%). Nevertheless, similarity with the reference strains of phylogenetically close relatives was lower than 40%. 16S rRNA gene sequences were compared with those of other species of Halomonas and other Gram-negative bacteria and they were sufficiently distinct phylogenetically from other recognized Halomonas species to warrant their designation as a novel species. The name Halomonas maura sp. nov. is therefore proposed, with strain S-31(T)(= CECT 5298(T) = DSM 13445(T)) as the type strain. The fatty acid composition of strain S-31(T) revealed the presence of 18:1 omega 7c, 16:1 omega 7c/2-OH i15:0 and 16:0 as the major components. Growth rate analysis showed that strain S-31(T) had specific cationic requirements for Na+ and Mg2+.