Abstract
Sulfur-oxidizing bacterium strain ORCS6 was isolated from acid sulfate soils at Owakudani, Hakone, Kanagawa Prefecture, Japan. This strain was rod-shaped, gram-negative, acidophilic and chemoautotrophic obligate aerobes. The similarity of the 16S rRNA gene sequence to Acidithiobacillus thiooxidans ATCC19377T is 94.14 %, Acidithiobacillus caldus DSM8584T is 95.59 %. The strain ORCS6 has an optimal growth temperature of 37°C but showed good growth even at 40°C. A. thiooxidans and A. caldus, according to a previous report, differ from the strain ORCS6 with respect to their sulfur utility. Since strain ORCS6 has different characteristics to A. thiooxidans and A. caldus, strain ORCS6 was identified and designated as a new strain, Acidithiobacillus sp. ORCS6.
