Marinobacter maroccanus sp. nov., a moderately halophilic bacterium isolated from a saline soil

During the taxonomic investigation of exopolymer producing halophilic bacteria, a rod shaped, motile, Gram-stain-negative, aerobic, halophilic bacterium, designated strain N4 T , was isolated from a natural saline soil located in the northern Morocco. The optimal growth of the isolate was at 30-37 ºC and at pH 6.0-9.0, in the presence of 5-7% (w/v) NaCl. Useful tests for the phenotypic differentiation of strain N4 T from other Marinobacter species included α-chymotrypsin and α-glucosidase activities and the carbohydrate assimilation profile. The major fatty acids detected in strain N4 T were C18:1 ω9c, C16:0, and C16:1 ω7c/C15:0 iso 2-OH. Sequence analysis of the 16S rRNA indicated that strain N4 T belonged to the genus Marinobacter and was closely related to Marinobacter adhaerens NC17506 T (99.04%), Marinobacter salsuginis SD-14B T (98.97%), and Marinobacter flavimaris SW-145 T (98.36%). Phylogenetic analysis of the rpoD gene sequence also showed that the nearest neighbours of strain N4 T were M. adhaerens (90.63%) and M. salsuginis (91.13%). Strain N4 T showed 87.98% similarity in the average nucleotide identity (ANI) with M. flavimaris and M. salsuginis , and 87.47% with M. adhaerens . In the in-silico genome-to-genome distance (GGD), strain N4 T showed DNA-DNA hybridization (DDH) values of 33.30% with M. adhaerens , 34.60% with M. flavimaris and 34.70% with M. salsuginis . DNA G+C content of N4 T was 57.3 mol%. Based on the results of phenotypic characterization, phylogenetic analysis and genome comparison, strain N4 T represents a novel species of the genus Marinobacter , for which the name Marinobacter maroccanus sp. nov. is proposed. The type strain is N4 T (=CECT 9525 T =LMG 30466 T ).