Paenibacillus agilis sp. nov., Paenibacillus cremeus sp. nov. and Paenibacillus terricola sp. nov., isolated from rhizosphere soils

Members of the genus Paenibacillus are well known for their metabolic versatility and great application potential in plant growth promotion. Three novel bacterial strains, designated N4 T , JC52 T and PR3 T , were isolated from rhizosphere soils and characterized by using a polyphasic taxonomic approach. The 16S rRNA gene sequence phylogenetic and phylogenomic analysis revealed that the three strains belonged to the genus Paenibacillus and formed three independent branches distinct from all reference strains. The results of DNA–DNA hybridization (DDH) and average nucleotide identity (ANI) analyses between the three strains and their relatives further demonstrated that the three strains represented different novel genospecies. Strain N4 T exhibited the highest similarity, ANI and digital DDH values with Paenibacillus assamensis DSM 18201 T (99.0/87.5/33.9 %) and Paenibacillus insulae DS80 T (97.2/–/18.2±1.2 %). Values for JC52 T with Paenibacillus validus NBRC 15382 T were 96.9, 73.3 and 19.6 %, and with Paenibacillus rigui JCM 16352 T were 96.1, 72.1 and 19.3 %. Values for PR3 T with Paenibacillus ginsengiterrae DCY89 T were 98.2, – and 31.8±1.5 %, with Paenibacillus cellulosilyticus ASM318225v1 T were 97.8, 83.3 and 26.7 %, and with Paenibacillus kobensis NBRC 15729 T were 97.6, 75.7 and 20.4 %. Cells of the three novel bacterial strains were Gram-positive, spore-forming, motile and rod-shaped. The novel species contained anteiso-C 15 : 0 and MK-7 as the predominant fatty acid and menaquinone, respectively. The novel strains have numerous similar known clusters of non-ribosomal peptide synthetases, siderophores, lanthipeptide, lassopeptide-like bacillibactin, paeninodin and polyketide-like chejuenolide A/B lankacidin C. Based on the distinct morphological, physiological, chemotaxonomic and phylogenetic differences from their closest phylogenetic neighbours, we propose that strains N4 T , JC52 T and PR3 T represent novel species of the genus Paenibacillus , with the names Paenibacillus agilis sp. nov. (=KACC 19717 T =JCM 32775 T ), Paenibacillus cremeus sp. nov. (=KACC 21221 T =NBRC 113867 T ) and Paenibacillus terricola sp. nov. (=KACC 21455 T =NBRC 114385 T ), respectively.