Microvirga subterranea gen. nov., sp. nov., a moderate thermophile from a deep subsurface Australian thermal aquifer
A strictly aerobic bacterium, strain FaiI4T, was isolated from free-flowing geothermal waters of a bore (bore register no. 3768) tapping the Great Artesian Basin of Australia. The non-sporulating, Gram-negative cells of strain FaiI4T produced light-pink colonies, were rod-shaped (1x1絭4 孩 and were motile by a single polar flagellum. Strain FaiI4T grew optimally at 41 àat a pH of 7簠and had an absolute requirement for yeast extract. The strain grew on casein hydrolysate, tryptone, gelatin, xylose and acetate in a medium supplemented with 0簶 or 0簰6 % yeast extract. Weak acid production was detected from glucose and arabinose. Catalase was produced. Nitrite was produced from nitrate. Strain FaiI4T was sensitive to antibiotics that inhibit growth of bacteria. The G+C content was 63統0絠mol%. Strain FaiI4T was a member of the class 'Alphaproteobacteria', phylum Proteobacteria, placed almost equidistantly between Methylobacterium species, Chelatococcus asaccharovorans and Bosea thiooxidans (similarity value of 93 %) as its nearest phylogenetic relatives. Phylogenetic and phenotypic evidence suggest that strain FaiI4T (=ATCC BAA-295T =DSM 14364T) should be placed as the type strain of a species in a newly created genus, for which the name Microvirga subterranea gen. nov., sp. nov. is proposed.
International Journal of Systematic and Evolutionary Microbiology