A Gram-stain-positive, aerobic, endospore-forming bacterial strain, isolated from the rhizosphere of Zea mays, was studied for its detailed taxonomic allocation. Based on 16S rRNA gene sequence similarity comparisons, strain JJ-447T was shown to be a member of the genus Paenibacillus, most closely related to the type strain of Paenibacillus solanacearum (97.8 %). The 16S rRNA gene sequence similarity values to all other Paenibacillus species were below 97.0 %. DNA-DNA hybridization (DDH) values with the type strain of P. solanacearum were 35.9 % (reciprocal 27%), respectively. The average nucleotide identity and in silico DDH values with the type strain of P. solanacearum were 84.86 and 28.9 %, respectively. The quinone system of strain JJ-447T consisted exclusively of menaquinones and the major component was MK-7 (96.4 %) but minor amounts of MK-6 (3.6 %) were detected as well. The polar lipid profile consisted of the major components diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol and an unidentified aminolipid. Major fatty acids were iso- and anteiso-branched with the major compounds anteiso-C15 : 0 and iso-C15 : 0. Physiological and biochemical characteristics allowed a further phenotypic differentiation of strain JJ-447T from the most closely related species on the basis of d-glucose, l-arabinose and d-mannose assimilation and other physiological tests. Thus, JJ-447T represents a novel species of the genus Paenibacillus, for which the name Paenibacillus allorhizosphaerae sp. nov. is proposed, with JJ-447T (=LMG 31601T=CCM 9021T=CIP 111802T) as the type strain.
Keywords: Paenibacillus allorhizosphaerae; Zea mays; endophyte; plant associated; taxonomy.