Taxonomic revision of the genus Geobacillus: emendation of Geobacillus, G. stearothermophilus, G. jurassicus, G. toebii, G. thermodenitrificans and G. thermoglucosidans (nom. corrig., formerly 'thermoglucosidasius'); transfer of Bacillus thermantarcticus to the genus as G. thermantarcticus comb. nov.; proposal of Caldibacillus debilis gen. nov., comb. nov.; transfer of G. tepidamans to Anoxybacillus as A. tepidamans comb. nov.; and proposal of Anoxybacillus caldiproteolyticus sp. nov.

摘要

Sixty-two strains of thermophilic aerobic endospore-forming bacteria were subjected to polyphasic taxonomic study including 16S rRNA gene sequence analysis, polar lipid and fatty acid analysis, phenotypic characterization, and DNA-DNA hybridization experiments. Distinct clusters of the species Geobacillus stearothermophilus, Geobacillus thermodenitrificans, Geobacillus toebii and Geobacillus thermoglucosidasius were formed, allowing their descriptions to be emended, and the distinctnesses of the poorly represented species Geobacillus jurassicus, Geobacillus subterraneus and Geobacillus caldoxylosilyticus were confirmed. It is proposed that the name Geobacillus thermoglucosidasius be corrected to G. thermoglucosidans. Bacillus thermantarcticus clustered between Geobacillus species on the basis of 16S rRNA gene sequence analysis, and its transfer to Geobacillus is proposed. The above-mentioned species, together with Geobacillus thermoleovorans and Geobacillus thermocatenulatus, form a monophyletic cluster representing the genus Geobacillus. The distinctness of 'Geobacillus caldoxylosilyticus' was confirmed and it is proposed that it be accommodated, along with Geobacillus tepidamans, in Anoxybacillus. The type strain of Geobacillus debilis was not closely related to any members of Anoxybacillus and Geobacillus, and it is proposed that this species be placed in the new genus Caldibacillus.