Genomic metrics analyses indicate that Paenibacillus azotofixans is not a later synonym of Paenibacillus durus.

Paenibacillus durusand Paenibacillus azotofixans, both Gram-stain-positive and endospore-forming bacilli, have been considered to be a single species. However, a preliminary computation of their average nucleotide identity (ANI) values suggested that these species are not synonyms. Given this, the taxonomic attributions of these species were evaluated through genomic and phylogenomic approaches. Although the identity of 16S rRNA gene sequences of P. durus DSM 1735T and P. azotofixans ATCC 35681T are above the circumscription species threshold, genomic metrics analyses indicate otherwise. ANI, gANI and OrthoANI values computed from their genome sequences were around 92 %, below the species limits. Digital DNA-DNA hybridization and MUMi estimations also corroborated these observations. In fact, in all metrics, Paenibacillus zanthoxyli JH29T seemed to be more similar to Paenibacillus azotofixans. ATCC 35681T than P. durus DSM 1735T. Phylogenetic analyses based on concatenated core-proteome and concatenated gyrB, recA, recN and rpoB genes confirmed that P. zanthoxyli is the closest Paenibacillus species to P. azotofixans. A review of the phenotypic profiles from these three species revealed that their biochemical repertoires are very similar, although P. azotofixans ATCC 35681T can be differentiated from P. durus DSM1735T in 13 among more than 90 phenotypic traits. Considering phylogenetic and genomic analyses, Paenibacillus azotofixans should be considered as an independent species, and not as a later synonym of Paenibacillus durus.

Genome-based reclassification of Paenibacillus dauci as a later heterotypic synonym of Paenibacillus shenyangensis.

Paenibacillus shenyangensis and Paenibacillus dauci are Gram-stain-positive, rod-shaped and endospore-forming bacteria originally isolated from soil and carrot samples, respectively, in China. Preliminary comparative genomic analysis showed that these bacteria could constitute a single species. Therefore, in this study, their taxonomic statuses were clarified through distinct genomic metrics and phylogenetic analyses. Paenibacillus shenyangensis A9T and P. dauci H9T presented values of average nucleotide identity (ANI) and its derivative metrics (gANI and OrthoANI) ranging from 97.88 to 98.08 %, and digital DNA-DNA hybridization equal to 89.08 %. Furthermore, the identities of 16S rRNA, gyrB, rpoB, recA and recN genes were all equal or higher than 98.7 %. Phylogenies of these marker genes and the concatenated core proteome were congruent in the sense that P. shenyangensis A9T and P. dauci H9T are the closest type-strains of the genus Paenibacillus. A review of their profiles revealed that these strains do not present pronounced differences at the phenotypic and chemotaxonomic levels. Considering phylogenetic, genomic, phenotypic and chemotaxonomic data, P. dauci should be reclassified as a later heterotypic synonym of P. shenyangensis.