Paenibacillus suaedae sp. nov. and Paenibacillus violae sp. nov., isolated from the roots of Suaeda japonica Makino and Viola mandshurica W. Becker with plant growth-promoting potential

Two novel Gram-positive strains, chi10 T and PFR10 T , were isolated from the roots of Suaeda japonica Makino and Viola mandshurica W. Becker, respectively. The strains are facultatively aerobic, rod-shaped, motile via peritrichous flagella and endospore-forming. Strains chi10 T and PFR10 T showed the highest 16S rRNA gene sequence similarity to Paenibacillus alvei DSM 29 T (99.0%) and Paenibacillus planticolens LMG 31457 T (99.3%). Furthermore, the phylogenetic and phylogenomic analyses demonstrated that strains chi10 T and PFR10 T were closely related to the genus Paenibacillus . The digital DNA–DNA hybridization (dDDH) values for strains used in the phylogenetic analysis and strain chi10 T ranged from 19.6 to 28.4%, while for strain PFR10 T , the values ranged from 19.8 to 53.5%, according to the Genome-to-Genome Distance Calculator 3.0, which were all less than 70%. Additionally, the dDDH value between strains chi10 T and PFR10 T was 22.0%, confirming that they are different species of the genus Paenibacillus . The average nucleotide identity between chi10 T and PFR10 T and other species of the genus Paenibacillus were 68.4–84.7% and 67.8–93.6%, respectively. In addition, the major polar lipids of chi10 T and PFR10 T consisted of diphosphatidylglycerol, phosphatidylglycerol and phosphatidylethanolamine. The major fatty acid profile of strain chi10 T was iso-C 15 : 0 and anteiso-C 15 : 0 , whereas the major fatty acid profile of strain PFR10 T was iso-C 15 : 0 , anteiso-C 15 : 0 and iso-C 16 : 0 . The sole respiratory quinone in strains chi10 T and PFR10 T was menaquinone-7. Phylogenomic, phenotypic and genome analyses strongly indicated that chi10 T and PFR10 T could be two novel Paenibacillus species for which the names Paenibacillus suaedae sp. nov. (type strain chi10 T = KACC 23258 T = TBRC 17803 T ) and Paenibacillus violae sp. nov. (type strain PFR10 T = KACC 23263 T = TBRC 17804 T ) are proposed, respectively.