The first evidence of Acidithiobacillus albertensis in weathered ore samples from active gold mine Hodruša-Hámre (Slovakia)

Abstract

Sulphur-oxidising autotrophic bacterial communities in deep biosphere from weathered ore samples from active gold mine Hodruša-Hámre, Slovakia were analysed using cultivation approach followed by DNA extraction, PCR amplification and 16S rRNA gene analyses. Indirect measurement of pH changes in cultivation media evidenced the presence of acidophilic bacteria with active production of acids. The decrease of pH was observed at the beginning of isolation and later pH in range of 1.5 – 2 was maintained in both, sulphuric acid and thiosulphate, media. The presence of homogenous population of gram-negative rods was proved by Gram staining. Molecular analyses have revealed that the population of sulphur-oxidising bacteria in gold mine is dominated by a single species of Aciditiobacillus genus, identified as A. albertensis, suggesting the low level of autotrophic bacteria diversity in deep deposits. For the first time this species was isolated from weathered rocks of a gold mine subsurface environment.