Taxogenomics of the Genus Cyclobacterium: Cyclobacterium xiamenense and Cyclobacterium halophilum as Synonyms and Description of Cyclobacterium plantarum sp. nov.

摘要

The genus belongs to the phylum and includes eight species. Our study, based on the genomic parameters in silico DNA–DNA hybridization (GGDC), average nucleotide identity (OrthoANI), and average amino acid identity (AAI), confirmed that all current species of belong to this genus and constitute a coherent phylogenomic group, but with species forming two separate branches. In addition, the genome-based analyses revealed that and are members of the same species. Besides, we carried out a taxonomic characterization of the new strain GBPx2 , isolated from the halophytic plant sp. Analysis of its 16S rRNA gene sequence showed the highest sequence similarity (97.5%) to HY9 . Percentages of GGDC and OrthoANI between strain GBPx2 and species of the genus were lower than the threshold value for species delineation. The DNA G+C content was 43.0 mol%. The polar lipids included phosphatidylethanolamine as well as one unidentified phospholipid and four unidentified lipids, and its major cellular fatty acids were iso-C and summed feature 3 (C and/or iso-C 2-OH). The only quinone present was menaquinone 7. Based on a combination of phenotypic, chemotaxonomic, and phylogenomic features, the GBPx2 strain represents a novel species of the genus , for which the name sp. nov. is proposed. The type strain of is GBPx2 (= IBRC-M 10634 = LMG 28551 ).