Genome-based taxonomic analysis of the genus Pseudoalteromonas reveals heterotypic synonyms

The Pseudoalteromonas genus comprises members that have been demonstrated to play significant ecological roles and produce enzymes, natural products, and activities that are beneficial to the environment and economy. A comprehensive evaluation of the genus revealed that the genomes of several Pseudoalteromonas species are highly similar to each other, exceeding species cutoff values. This evaluation involved determining and comparing the average nucleotide identity, in silico DNA–DNA hybridization, average amino acid identity, and the difference in G + C% between Pseudoalteromonas type strains with publicly available genomes. The genome of the Pseudoalteromonas elyakovii type strain was further assessed through additional sequencing and genomic comparisons to historical sequences. These findings suggest that six Pseudoalteromonas species, namely P. mariniglutinosa, P. donghaensis, P. maricaloris, P. elyakovii, P. profundi, and P. issachenkonii, should be reclassified as later heterotypic synonyms of the following validly published species: P. haloplanktis, P. lipolytica, P. flavipulchra, P. distincta, P. gelatinilytica, and P. tetraodonis. Furthermore, two names without valid standing, ‘P. telluritireducens’ and ‘P. spiralis’, should be associated with the validly published Pseudoalteromonas species P. agarivorans and P. tetraodonis, respectively.