Paenibacillus cucumis sp. nov., isolated from a cucumber plant.

A Gram-positive-staining, aerobic, endospore-forming bacterial strain, isolated from the stem of a cucumber plant, was studied in detail for its taxonomic position. Based on 16S rRNA gene sequence similarity comparisons, strain AP-115T was grouped into the genus Paenibacillus, most closely related to Paenibacillus amylolyticus (98.8 %), Paenibacillus tundrae and Paenibacillus barcinonensis (both 98.4 %). The 16S rRNA gene sequence similarity to other species of the genus Paenibacillus was ≤98.4 %. Chemotaxonomic characterization supported allocation of the strain to the genus Paenibacillus. The quinone system contained exclusively menaquinone MK-7, and in the polar lipid profile diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine and phosphatidylserine were predominating. The major component in the polyamine pattern was spermidine, and the diagnostic diamino acid of the peptidoglycan was meso-diaminopimelic acid. The major fatty acids were iso- and anteiso-branched fatty acids. The results of physiological and biochemical tests allowed phenotypic differentiation of strain AP-115T from closely related species. Thus, AP-115T represents a novel species of the genus Paenibacillus, for which the name Paenibacillus cucumis sp. nov. is proposed, with AP-115T (=LMG 29222T=CCM 8653T) as the type strain.