Paenibacillus rhizoplanae sp. nov., isolated from the rhizosphere of Zea mays.

Abstract

A Gram-stain-positive, aerobic, endospore-forming bacterial strain isolated from the rhizosphere of Zea mays was studied to determine its detailed taxonomic position. Based on 16S rRNA gene sequence similarity comparisons, strain JJ-64T was shown to be a member of the genus Paenibacillus, most closely related to the type strains of Paenibacillus silagei (99 %) and Paenibacillus borealis (97.5 %). 16S rRNA gene sequence similarity to all other Paenibacillus species was ≤97.5 %. DNA-DNA hybridization values to the type strains of P. silagei and P. borealis were 51 % (reciprocal 25 %) and 31 % (reciprocal 37 %), respectively. The presence of meso-diaminopimelic acid as the diagnostic diamino acid of the peptidoglycan, the major quinone MK-7 and the polyamine pattern with spermidine as the major component were well in line with the characteristics of the genus Paenibacillus. Furthermore, the polar lipid profile of strain JJ-64T with the predominant lipids diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, phosphatidylserine and two unidentified aminophospholipids reflected the close phylogenetic relatedness to P. silagei. Major fatty acids were iso- and anteiso-branched components. Physiological and biochemical characteristics allowed the further phenotypic differentiation of strain JJ-64T from the most closely related species. Thus, strain JJ-64T represents a novel species of the genus Paenibacillus, for which the name Paenibacillus rhizoplanae sp. nov. is proposed. The type strain is JJ-64T (=LMG 29875T=CCM 8725T).