Reclassification of Mameliella phaeodactyli, Mameliella atlantica, Ponticoccus lacteus and Alkalimicrobium pacificum as later heterotypic synonyms of Mameliella alba and an emended description of Mameliella alba

The aim of the study was to reclarify the taxonomic status of four species, Mameliella phaeodactyli, Mameliella atlantica, Ponticoccus lacteus and Alkalimicrobium pacificum, by using a polyphasic taxonomic approach. A combination of physiological properties of the four type strains, KD53(T), L6M1-5 JL351(T) and F15(T), was consistent with those of the closest type strain JLT354-W-T of Mameliella alba. The 16S rRNA gene sequences of the five type strains shared 100% identity. The close relationship between the five strains was underpinned by the results of chemotaxonomic characteristics, including the fatty acids, quinone and polar lipids. The pairwise digital DNA-DNA hybridization values among the five strains were well above 70 %, considered the threshold value for species definition. In this case a further statement of Rule 24a applies, in which priority of names is determined by the date of the original publication. Hence, we propose that that Mameliella phaeodactyli, Mameliella atlantica, Ponticoccus lacteus and Alkalimicrobium pacificum should be regarded as later heterotypic synonyms of Mameliella alba.