Tumebacillus permanentifrigoris gen. nov., sp. nov., an aerobic, spore-forming bacterium isolated from Canadian high Arctic permafrost.

A Gram-positive, aerobic, rod-shaped bacterium (strain Eur1 9.5(T)) was isolated from a 9-m-deep permafrost sample from the Canadian high Arctic. Strain Eur1 9.5(T) could not be cultivated in liquid medium and grew over the temperature range 5-37 degrees C; no growth was observed at 42 degrees C and only slow growth was observed at 5 degrees C following 1 month of incubation. Eur1 9.5(T) grew over the pH range 5.5-8.9 and tolerated NaCl concentrations of 0-0.5 % (w/v). Eur1 9.5(T) grew heterotrophically on complex carbon substrates and chemolithoautotrophically on inorganic sulfur compounds, as demonstrated by growth on sodium thiosulfate and sulfite as sole electron donors. Eur1 9.5(T) contained iso-C(15 : 0) as the major cellular fatty acid and menaquinone 7 (MK-7) as the major respiratory quinone. The cell-wall peptidoglycan was of type A1gamma. The DNA G+C content was 53.1 mol%. The 16S rRNA gene sequence of strain Eur1 9.5(T) was only distantly related (<or=87 % sequence similarity over 1407 bp) to any recognized bacterial species. Based on physiological and phylogenetic analyses, strain Eur1 9.5(T) is suggested to represent a novel species of a new genus, for which the name Tumebacillus permanentifrigoris gen. nov., sp. nov. is proposed. The type strain of Tumebacillus permanentifrigoris is Eur1 9.5(T) (=DSM 18773(T) =JCM 14557(T)).