Paenibacillus lycopersici sp. nov. and Paenibacillus rhizovicinus sp. nov., isolated from the rhizosphere of tomato (Solanum lycopersicum)

Two Gram-stain-positive, rod-shaped, endospore-forming bacteria, designated 12200R-189^T and 14171R-81^T were isolated from the rhizosphere of tomato plants. The 16S rRNA gene sequence similarity between strains 12200R-189^T and 14171R-81^T were 97.2%. Both strains showed the highest 16S rRNA gene sequence similarities to Paenibacillus sacheonensis SY01^T (96.3% and 98.0%, respectively). The genome of strain 12200R-189^T was approximately 6.7 Mb in size with 5,750 protein-coding genes (CDSs) and the G + C content was 58.1 mol%, whereas that of strain 14171R-81^T comprised one chromosome of 7.0 Mb and two plasmids (0.2 Mb each) with 6,595 CDSs and the G + C content was 54.5 mol%. Comparative genome analysis revealed that average nucleotide identity (ANI) and digital DNA-DNA hybridization (dDDH) values among 12200R-189^T, 14171R-81^T, and other closely related species were below the cut-off levels 95% and 70%, respectively. Strain 12200R-189^T grew at a temperature range of 15-40°C, pH 6.0-9.0, and 0-3% NaCl (w/v), whereas strain 14171R-81^T grew at a temperature range of 10-37°C, pH 6.0-8.0, and 0-1% NaCl (w/v). Menaquinone-7 (MK-7) was the only isoprenoid quinone detected in both strains. The predominant cellular fatty acids (> 10%) were iso-C_15:0, anteiso-C_15:0, and iso-C_16:0. The polar lipids of strain 12200R-189^T were diphosphatidylglycerol (DPG), phosphatidylglycerol (PG), phosphatidylethanolamine (PE), aminophospholipid (APL), phospholipid (PL), phosphatidylglycolipid (PGL), and four aminophosphoglycolipids (APGLs) and those of strain 14171R-81^T were DPG, PG, PE, APL, three PLs, two PGLs, and three APGLs. Based on phylogenetic, genomic, phenotypic, and chemotaxonomic analyses, strains 12200R-189^T and 14171R-81^T represent two novel species of the genus Paenibacillus, for which the names Paenibacillus lycopersici sp. nov. and Paenibacillus rhizovicinus sp. nov. are proposed. The type strains are 12200R-189^T (= KACC 19916^T = CCTCC AB 2020027^T) and 14171R-81^T (= KACC 19915^T = CCTCC AB 2020026^T).

Paenibacillus flagellatus sp. nov., isolated from selenium mineral soil

Strain DXL2^T, a Gram-stain-negative, rod-shaped, endospore-forming, motile, aerobic bacterium, was isolated from selenium mineral soil. DXL2^T had the highest 16S rRNA gene sequence similarities with those of Paenibacillus ginsengarviGsoil 139^T (96.8 %), Paenibacillushemerocallicola DLE-12^T (95.5 %) and Paenibacillus hodogayensisSG^T (95.4 %). The genome size of DXL2^T was 7.24 Mb, containing 6243 predicted protein-coding genes, with a DNA G+C content of 60.2 mol%. DXL2^T contained meso-diaminopimelic acid in the cell-wall peptidoglycan. The major cellular fatty acids were anteiso-C15 : 0, iso-C16 : 0 and iso-C15 : 0. The major quinone was menaquinone 7. The polar lipids were diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, two aminophospholipids, an unidentified aminolipid, phosphatidylmethylethanolamine, an unidentified glycolipid and an unidentified phospholipid. Compared with the other strains, DXL2^T had a specific phospholipid and a specific aminolipid, it hydrolyzed Tween 40 and could not assimilate potassium gluconate. On the basis of the phenotypic, chemotaxonomic and phylogenetic results, strain DXL2^T represents a novel species within the genus Paenibacillus, for which the name Paenibacillusflagellatus sp. nov. is proposed. The type strain is DXL2^T (=KCTC 33976^T=CCTCC AB 2018054^T).