Marinomonas gallaica sp. nov. and Marinomonas atlantica sp. nov., isolated from reared clams (Ruditapes decussatus).

Three Gram-negative bacterial strains (Cmf 17.2T, Rd 20.33 and Cmf 18.22T) isolated from reared clams in Galicia were subjected to a taxonomic study, based on genetic and phenotypic characterization. Analysis of the 16S rRNA gene allowed the identification of the strains as members of the genus Marinomonas, sharing the highest similarity with Marinomonas aquimarina CECT 5080T (97.8 %-98.5 % 16S rRNA gene sequence similarity). Phylogenetic analysis of the sequences showed that the three isolates formed two different groups distantly related to their closest relative, M. aquimarina. DNA-DNA hybridizations were performed to confirm the taxonomic position and the results were below the recommended threshold for species delimitation, specifically 44.5 % (Cmf 17.2T with M. aquimarina CECT 5080T) and 55 % (Cmf 18.22Twith M. aquimarina CECT 5080T). Furthermore, the average nucleotide identity (ANIb, ANIm and OrthoANI) and in silico estimated DNA-DNA reassociation values among Cmf 17.2T, Cmf 18.22T and M. aquimarina CECT 5080T were in all cases below the respective threshold for species differentiation. The estimated G+C content of the genomic DNA was found to be 45.3 % (Cmf 17.2T) and 44.6 % (Cmf 18.22T). The principal fatty acids of the strains were found to be summed feature 3 (C16 : 1 ω7c/C16 : 1ω6c), summed feature 8 (C18 : 1ω7c/C18 : 1ω6c), C16 : 0, C12 : 0 and C10 : 0 3-OH. The results obtained on the characterization of the clam isolates indicate that they represent two novel species of the genus Marinomonas, for which the names Marinomonas gallaica sp. nov. (type strain Cmf 17.2T=CECT 9049T=LMG 29243T) and Marinomonas atlantica sp. nov. (type strain Cmf 18.22T=CECT 9050T=LMG 29244T) are proposed.