This study describes the isolation and characterization of five moderately halophilic gram-positive cocci from hypersaline environments near Alicante, Spain. These organisms were nonmotile, nonsporing, reddish-orange pigmented cocci that grew optimally at 10% salt concentration and 37°C. All strains were strictly aerobic, catalase and oxidase positive, and contained meso-diaminopimelic acid in their cell walls. DNA-DNA hybridization studies showed the five isolates formed a cohesive group with 70-100% homology to each other but only 0-38% homology to related species. The isolates had G+C content ranging from 45.6 to 49.3 mol% and contained menaquinones MK-7 and MK-8. Based on phenotypic, chemotaxonomic, and genetic characterization differing from previously described moderately halophilic gram-positive cocci, the authors propose these strains constitute a new species: Marinococcus hispanicus, with type strain J-82 (ATCC 49259).

Key findings

• Five moderately halophilic gram-positive cocci isolated from solar saltern environments form a genetically cohesive group with DNA-DNA homology levels of 70-100% among strains but only 0-38% relatedness to other known moderately halophilic bacteria
• Marinococcus hispanicus differs from previously described gram-positive halophilic cocci in pigmentation (reddish orange), acid production patterns, menaquinone composition (MK-7 and MK-8 rather than MK-7 alone), and multiple phenotypic characteristics
• The new species has DNA G+C content of 45.6-49.3 mol%, meso-diaminopimelic acid in cell walls, grows optimally at 10% salt and 37°C, and produces characteristic reddish-orange pigmentation