A Gram-negative, aerobic, moderately halophilic bacterium, designated Set74(T), was isolated from brine of a salt concentrator at Ain Oulmene, Algeria. The strain grew optimally at 37-40 degrees C, at pH 6.5-7.0 and with 5-7.5% (w/v) NaCl and used various organic compounds as sole carbon, nitrogen and energy sources. Ubiquinone 9 (Q-9) was the major lipoquinone. The main cellular fatty acids were C-16:0, C-18:1 omega 9c, summed feature 7 (ECL 18.846; C-19:0 cyclo omega 10c and/or C-19:1 omega 6c), C-12:0 3-OH, C-16:1 omega 9C, C-18:0 and C-12:0. The major polar lipids were phosphatidylglycerol, diphosphatidylglycerol and phosphatidylethanolamine. The G + C content of the genomic DNA was 57.4 mol%. The 16S rRNA gene sequence analysis indicated that strain Set74(T) was a member of the genus Marinobacter. The closest relatives of strain Set74(T) were Marinobacter santoriniensis NKSG1(T) (97.5% 16S rRNA gene sequence similarity) and Marinobacter koreensis DD-M3(T) (97.4%). DNA-DNA relatedness between strain Set74(T) and M. santoriniensis DSM 21262(T) and M. koreensis DSM 17924(T) was 45 and 37%, respectively. On the basis of the phenotypic, chemotaxonomic and phylogenetic features, a novel species, Marinobacter oulmenensis sp. nov., is proposed. The type strain is Set74(T) (=CECT 7499(T) =DSM 22359(T)).