Marinomonas spartinae sp. nov., a novel species with plant-beneficial properties

Two strains of Gram-stain-negative, chemo-organotrophic, aerobic and halophilic gammaproteobacteria, isolated from within the stem and roots of Spartina maritima in salt marshes from the south Atlantic Spanish coast, were found to represent a novel species in the genus Marinomonas through phylogenetic analysis of their 16S rRNA genes and phenotypic characterization. 16S rRNA gene sequences of the two strains shared < 96.2% similarity with other Marinomonas species, with Marimonas alcarazii being the most similar in sequence. They required sodium ions for growth, were able to thrive at low (4 °C) temperatures and at salinities of 12-15%, were unable to hydrolyse any tested macromolecule except casein, and grew with different monosaccharides, disaccharides, sugar alcohols, organic acids and amino acids. The novel species differed from other Marinomonas species in the use of several sole carbon sources, its temperature and salinity ranges for growth, ion requirements and cellular fatty acid composition, which included C16:0, C16:1 and C18:1 as major components and C10:0 3-OH, C12:0 and C12:0 3-OH as minor components. The name Marinomonas spartinae sp. nov. is proposed, with SMJ19T (=CECT 8886T=KCTC 42958T) as the type strain.