Ornithinibacillus gen. nov., with the species Ornithinibacillus bavariensis sp. nov. and Ornithinibacillus californiensis sp. nov.

Abstract

A Gram-positive, aerobic, rod-shaped, motile, endospore-forming bacterium was isolated from pasteurized milk from Bavaria, Germany. 16S rRNA gene sequence similarities indicated that strain WSBC 24001T was most closely related to Virgibacillus species (95.3–96.1 %), Oceanobacillus species (95.6–95.7 %), Bacillus firmus IAM 12464T (95.5 %) and Bacillus niacini IFO 15566T (95.2 %). However, strain WSBC 24001T showed the highest level of sequence similarity to an unnamed strain, MB-9T (97.6 %), which was isolated from coastal surface sediments in California. Hence, this strain was included in our study. The genomic DNA G+C contents of strains WSBC 24001T and MB-9T were 36.4 mol and 40.8 mol%, respectively. The major respiratory quinone of both strains was menaquinone MK-7 and the peptidoglycan type was A4β (l-orn←d-Asp). The polar lipid profiles of these strains contained a predominance of diphosphatidylglycerol and moderate to minor amounts of phosphatidylglycerol, an unknown phospholipid and an unknown aminophospholipid. However, strain WSBC 24001T could be distinguished from strain MB-9T by the presence of an unknown lipid. The fatty acid profiles of the two strains comprised mainly iso- and anteiso-branched acids, but showed some significant quantitative differences in the amounts of certain acids. The DNA–DNA relatedness value (15.5 %) clearly demonstrated that strains WSBC 24001T and MB-9T are representatives of two different species. On the basis of their phylogenetic position and morphological, physiological and chemotaxonomic properties, a novel genus is proposed, Ornithinibacillus gen. nov., with two novel species, the type species Ornithinibacillus bavariensis sp. nov. (type strain WSBC 24001T=DSM 15681T=CCM 7096T) and Ornithinibacillus californiensis sp. nov. (type strain MB-9T=DSM 16628T=CCM 7237T).