Genome-based reclassification of Sphingopyxis ummariensis as a later heterotypic synonym of Sphingopyxis terrae, with the descriptions of Sphingopyxis terrae subsp. terrae subsp. nov. and Sphingopyxis terrae subsp. ummariensis subsp. nov.

During the phylogenetic analysis of the genus Sphingopyxis, we found that an incorrect 16S rRNA gene sequence (accession number: D13727) was provided in the original description of Sphingopyxisterrae NBRC 15098T and the wrong sequence has been adopted and used for a long time. It should be replaced by the new correct 16S rRNA gene sequence (accession number: MF618306). The new sequence shared the highest similarity (99.8 %) with that of Sphingopyxisummariensis DSM 24316T. The average nucleotide identity (ANI) (96.87 %) and digital DNA-DNA hybridization (75.30 %) values based on the whole-genome sequences and almost the same phenotypic and chemotaxonomic characteristics of the two type strains revealed thatSphingopyxisummariensis should be a later heterotypic synonym ofSphingopyxisterrae. However, the distinctions in the genome size, hydrolysis of aesculin, α-glucosidase and particularly the fatty acid profiles strongly support that strain DSM 24316T should be considered to represent a novel subspecies ofSphingopyxisterrae. Two novel subspecies are therefore proposed, namely Sphingopyxisterraesubsp. terrae subsp. nov. (type strain E-1-AT=NBRC 15098T=JCM 10195T=DSM 8831T=LMG 17326T) and Sphingopyxisterraesubsp. ummariensis subsp. nov. (type strain UI2T=DSM 24316T=CCM 7428T=MTCC 8591T).