Bacillus rhizoplanae sp. nov. from maize roots

A Gram-stain-positive, aerobic and endospore-forming bacterial strain, isolated from the root surface of maize (Zea mays) was taxonomically studied. It could be clearly shown that, based on 16S rRNA gene sequence similarity comparisons, strain JJ-63(T) is a member of the genus Bacillus, most closely related to the type strain of Bacillus pseudomycoides (98.61%), followed by Bacillus cereus (98.47%). Detailed phylogenetic analysis based on the 16S rRNA gene and the 87 proteins conserved within the phylum Firmicutes placed the strain into the Cereus clade. The average nucleotide identity, average amino acid identity and digital DNA-DNA hybridization values against the type strain of B. pseudomycoides were 80.97, 81.45 and 26.30 %, respectively. The quinone system of strain JJ-63(T) consisted exclusively of menaquinone MK-7. The polar lipid profile consisted of the major components diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol and an unidentified glycolipid. Major fatty acids were iso- and anteiso-branched with the major compounds iso-C-15:0 and iso-C-17:0. Also, the characteristic compounds C-13:0 iso and C-16:1 cis10 were found. Physiological and biochemical characteristics allowed a further phenotypic differentiation of strain JJ-63(T) from the most closely related species. For this reason, JJ-63(T) represents a novel species of the genus Bacillus, for which the name Bacillus rhizoplanae sp. nov. is proposed, with JJ-63(T) (=LMG 32091(T)=CCM 9090(T)=DSM 111827(T)=CIP 111899(T)) as the type strain.

Automated summary

A novel Gram-stain-positive bacterium, Bacillus rhizoplanae sp. nov., was isolated from the root surface of maize, showing close phylogenetic relationships with Bacillus pseudomycoides and Bacillus cereus.