Geobacillus lituanicus sp. nov.

Abstract

Obligately thermophilic, aerobic, proteolytic, endospore-forming strain N-3T was isolated from a high-temperature oilfield in Lithuania. 16S rRNA gene sequence analysis placed this strain in genetic group 5 of the endospore formers. Geobacillus thermoleovorans appeared to be the closest phylogenetic neighbour (99·4 % sequence similarity). The G+C content of strain N-3T was 52·5 mol% and matched the range established for the genus Geobacillus. Studies of DNA–DNA relatedness and morphological and physiological analyses enabled strain N-3T to be described as a member of the genus Geobacillus, but could not assign this strain to any other known species of this genus. Results of this polyphasic study allowed characterization of strain N-3T as a novel species in the genus Geobacillus – Geobacillus lituanicus sp. nov. This species can be distinguished from G. thermoleovorans and Geobacillus stearothermophilus on the basis of 16S rRNA gene PCR-RFLP assays with the restriction endonucleases AluI, HaeIII and TaqI. The type strain of the novel species is N-3T (=DSM 15325T=VKM B-2294T).