LAUSR

The present study aimed to examine the taxonomic relationship between two alphaproteobacterial species, Mabikibacter ruber Choi et al. 2017 and Notoacmeibacter marinus Huang et al. 2017. Comparison of the 16S rRNA gene sequences revealed that they shared 99.9 % sequence similarity. Digital DNA-DNA hybridization (dDDH) estimate (79.8 %) and average nucleotide identity (ANI) value (97.8 %) compared between M. ruber YP382-1-A and N. marinus XMTR2A4T, were both greater than the threshold for bacterial species delineation, strongly supporting the hypothesis that they represented a single species. Moreover, M. ruber YP382-1-A and N. marinus XMTR2A4T shared similar physiological and biochemical properties and fatty acid profiles though they displayed distinct colony colours and other minor different properties, including genome size and ability to degrade cellulose, which were presumably due to the presence of a megaplasmid in the genome of M. ruber YP382-1-A. On the basis of the results of genomic analysis, phenotypic and physiological properties, and fatty acid composition, Mabikibacter ruber Choi et al. 2017 is a later heterotypic synonym of Notoacmeibacter marinus Huang et al. 2017 according to the priority of names determined by the date of original publication.