Tomitella biformata gen. nov., sp. nov., a new member of the suborder Corynebacterineae isolated from a permafrost ice wedge

Abstract

Gram-reaction-positive, aerobic, non-spore-forming, irregular rod-shaped bacteria, designated AHU1821(T) and AHU1820, were isolated from an ice wedge in the Fox permafrost tunnel, Alaska. The strains were psychrophilic, growing at -5 to 27°C. Phylogenetic analysis of the 16S rRNA and gyrB gene sequences indicated that the ice-wedge isolates formed a clade distinct from other mycolic-acid-containing bacteria within the suborder Corynebacterineae. The cell wall of strains AHU1821(T) and AHU1820 contained meso-diaminopimelic acid, arabinose and galactose, indicating chemotype IV. The muramic acids in the peptidoglycan were glycolated. The predominant menaquinone was MK-9(H(2)). The polar lipids consisted of diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylinositol, phosphatidylinositol mannosides and an unidentified glycolipid. The major fatty acids were hexadecenoic acid (C(16 : 1)), hexadecanoic acid (C(16 : 0)), octadecenoic acid (C(18 : 1)) and tetradecanoic acid (C(14 : 0)). Tuberculostearic acid was present in relatively small amounts (1 %). Strains AHU1821(T) and AHU1820 contained mycolic acids with 42-52 carbons. The DNA G+C content of the two strains was 69.3-71.6 mol% (T(m)). 16S rRNA, rpoB and recA gene sequences were identical between strains AHU1821(T) and AHU1820 and those of the gyrB gene showed 99.9 % similarity. Based on phylogenetic and phenotypic evidence, strains AHU1821(T) and AHU1820 represent a single novel species of a novel genus, for which the name Tomitella biformata gen. nov., sp. nov. is proposed. The type strain of Tomitella biformata is AHU1821(T) (=DSM 45403(T) =NBRC 106253(T)).