Genome-based reclassification of Paenibacillus panacisoli DSM 21345T as Paenibacillus massiliensis subsp. panacisoli subsp. nov. and description of Paenibacillus massiliensis subsp. massiliensis subsp. nov.

Bacteria of the genus Paenibacillus are relevant to humans, animals and plants. The species Paenibacillus massiliensis and Paenibacillus panacisoli are Gram-stain-positive and endospore-forming bacilli isolated from a blood culture of a leukemia patient and from soil of a ginseng field, respectively. Comparative analyses of their 16S rRNA genes revealed that the two Paenibacillus species could be synonyms (99.3% sequence identity). In the present study we performed different genomic analyses in order to evaluate the phylogenetic relationship of these micro-organisms. Paenibacillus massiliensis DSM 16942T and P. panacisoli DSM 21345T presented a difference in their G+C content lower than 1 mol%, overall genome relatedness index values higher than the species circumscription thresholds (average nucleotide identity, 95.57 %; genome-wide ANI, =96.51 %; and orthologous ANI, 96.25 %), and a monophyletic grouping pattern in the phylogenies of the 16S rRNA gene and the proteome core. Considering that these strains present differential biochemical capabilities and that their computed digital DNA-DNA hybridization value is lower than the cut-off for bacterial subspecies circumscription, we suggest that each of them form different subspecies of P. massiliensis, Paenibacillus massiliensis subsp. panacisoli subsp. nov. (type strain DSM 21345T) and Paenibacillus massiliensis subsp. massiliensis subsp. nov. (type strain DSM 16942T).