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

Abstract

A Gram-positive, rod-shaped, motile, endospore-forming strain, DXFW5T, was isolated from the rhizosphere soil of tomato. Strain DXFW5T grew at 20–50 °C (optimum, 25–37 °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.