Alicyclobacillus pohliae sp. nov., a thermophilic, endospore-forming bacterium isolated from geothermal soil of the north-west slope of Mount Melbourne (Antarctica)

Abstract

Gram-positive, rod-shaped, endospore-forming, thermophilic bacteria were isolated from a geothermal soil collected on the north-west slope of Mount Melbourne in Antarctica. They grew aerobically at 42-60 degrees C (optimum 55 degrees C) and at pH 4.5-7.5 (optimum pH 5.5). Phylogenetic analysis of 16S rRNA gene sequences showed that these isolates were related most closely to the type strain of Alicyclobacillus pomorum (91% similarity). Growth occurred in the presence of ferrous iron at micromolar concentrations and acid was produced from various sugars. Iso-branched fatty acids C(15:0) (45.56%) and C(17:0) (35.81%) were the most abundant cellular fatty acids. The DNA G+C content was 55.1 mol%. On the basis of phenotypic and phylogenetic characteristics, it is concluded that these strains represent a novel species of the genus Alicyclobacillus, for which the name Alicyclobacillus pohliae sp. nov. is proposed. The type strain is MP4(T) (=CIP 109385(T) =NCIMB 14276(T)).