Phylo-taxogenomics of the genus Tautonia with descriptions of Tautonia marina sp. nov., Tautonia rosea sp. nov., and emended description of the genus.

Four strains of Planctomycetes, (JC636, JC649, JC650, JC657) which are all salt and alkali tolerant, pink coloured, with spherical to oval shaped, Gram-stain-negative, non-motile cells were isolated from different regions of Chilika lagoon, India. All strains have obligate requirement for N-acetylglucosamine (NAG) and share highest 16S rRNA gene sequence identity with members of the genus Tautonia (<95%) of the family Isosphaeraceae. The 16S rRNA gene sequence identity between strains was >99.5%. Respiratory quinone for all the strains was MK6. Major fatty acids of all the strains were Cω9c, C and C. Major polar lipid of the strain JC650 was phosphatidylethanolamine, while, phosphatidylcholine and phosphatidylglycerol for strain JC657. Spermidine was the only common polyamine for all the four strains. Strains JC657, JC636 and JC649 shared highest phenotypic similarity along with 100% 16S rRNA gene sequence identity. Strains JC657, JC636 and JC649 differed from strain JC650 phenotypically, chemotaxonomically and genotypically, thus belong to a different species. The genomic size of strain JC650 and JC657 are 7.06 Mb and 6.96 Mb with DNA G + C content of 63.9 and 62.7 mol%, respectively. Based on phylogenetic, genomic (ANI, AAI, POCP, dDDH), chemotaxonomic, physiological and biochemical characteristics, we conclude that strains JC650 and JC657 (together with strains JC636, JC649) belong to the genus Tautonia and constitute two novel species for which we propose the names Tautonia marina sp. nov., and Tautonia rosea sp. nov., respectively. These two novel species are represented by the type strains JC650 (=KCTC 72177 = NBRC 113885) and JC657 (=KCTC 72597 = NBRC 113883) respectively.