Phenotypic and Chemotaxonomic Characterization of Marinococcus halophilus

Summary A phenotypic and chemotaxonomic study has been carried out on 55 moderately halophilic Gram-positive motile cocci isolated from hypersaline soils and solar salterns located near Alicante and Cadiz (Spain) and six reference strains. All the strains were examined for 158 morphological, physiological, biochemical, nutritional and antibiotic susceptibility tests, showing phenotypic characteristics similar to Marinococcus halophilus ; however, a different range of nutritional features was observed. Nine strains were chosen as representative isolates and were studied in more detail. All these strains had mesodiaminopimelic acid in the cell wall, DNA base composition ranging between 46.6 to 48.8 mol%, and menaquinone systems with seven isoprene units. The DNA-DNA hybridization experiments showed a high degree of homology (60–98%) between the representative strains examined and the type strain M. halophilus CCM 2706, and low levels (1–40%) with the other Gram positive moderately halophilic cocci studied, indicating that the fresh isolates and the species M. halophilus constitute a genospecies.