Paenibacillus rhizolycopersici sp. nov., an oligotrophic bacterium isolated from a tomato plant in China

A Gram-positive, rod-shaped, motile, endospore-forming strain, DXFW5T, was isolated from the rhizosphere soil of tomato. Strain DXFW5T grew at 20-50 degrees C (optimum, 25-37 degrees C), pH 5-8 (optimum, pH 7) and in the presence of 3 % NaCl. It was positive for catalase and oxidase. Phylogenetic analysis using 16S rRNA gene sequences showed this strain was most closely related to Paenibacillus timonensis DSM 16943T (98.0 %) and Paenibacillus barengoltzii DSM 22255T (97.4 %). The DNA G+C content was 52.9 mol%. The digital DNA-DNA hybridization values between strain DXFW5T and P. timonensis DSM 16943T, P. barengoltzii DSM 22255T and P. macerans DSM 24T were 33.1, 24.9 and 21.2 %, respectively. The average nucleotide identity values between strain DXFW5T and P. timonensis DSM 16943T, P. barengoltzii DSM 22255T and P. macerans DSM 24T were 86.93, 81.77 and 75.98 %, respectively. The major fatty acids were anteiso- C15: 0 (55.1 %), iso- C16: 0 (13.2 %) and C16: 0 (10 %). The polar lipids of strain DXFW5T consisted of diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine two unidentified phospholipids and three unidentified lipids. MK -7 was the major isoprenoid quinone. Based on these results, it was concluded that the isolate represents a novel species of the genus Paenibacillus, for which the name Paenibacillus rhizolycopersici sp. nov. is proposed, with DXFW5T (=ACCC 61751T=JCM 34488T) as the type strain.

Automated summary

A novel strain, DXFW5T, was isolated from the rhizosphere soil of tomato. The strain exhibited Gram-positive, rod-shaped morphology, motility, and endospore formation. Based on phylogenetic analysis using 16S rRNA gene sequences, the closest relatives of strain DXFW5T were Paenibacillus timonensis DSM 16943T and Paenibacillus barengoltzii DSM 22255T. The strain showed distinctive characteristics, including growth at certain temperature and pH ranges, and specific fatty acid composition and polar lipids.