Domibacillus tundrae sp. nov., isolated from active layer soil of tussock tundra in Council, Alaska

Abstract

A novel Gram-positive, spore-forming, aerobic, motile and rod-shaped bacterium designated as strain PAMC 80007T was isolated from active layer soil sample of moist acidic tundra in Council, Alaska. Optimal growth of strain PAMC 80007T was observed at 30 ºC, pH 7.0 and in the presence of 2 % (w/v) NaCl. Phylogenetic analysis based on 16S rRNA gene sequence indicated that strain PAMC 80007T belonged to the genus Domibacillus. This strain was closely related to Domibacillus enclensis (98.3 %), D. robiginosus (98.3 %) and D. indicus (97.2 %). Genomic DNA G+C content was 43.5 mol % and genomic relatedness analyses based on the average nucleotide identity and the genome-to-genome distance showed that strain PAMC 80007T is clearly distinguished from the closely related Domibacillus species. The major fatty acids (>5 %) were iso-C15:0 (24.7 %), C16:1 ω11c (16.8 %), anteiso-C15:0 (16.5 %), C16:0 (15.6 %) and anteiso-C17:0 (8.7 %). The major respiratory isoprenoid quinines MK-6 and MK-7, and the polar lipid profile contained diphosphatidylglycerol, phosphatidylglycerol, phosphoglycolipid, phospholipid and two unidentified lipids. The major whole-cell sugar was ribose with minor quantity of glucose and meso-diaminopimelic acid (type A1γ) was present in the cell-wall peptidoglycan. Results from polyphasic study suggested that strain PAMC80007T is a novel species of the genus Domibacillus for which the name Domibacillus tundrae sp. nov. is proposed.