Cultivable Microbiota Associated with Gold Ore from the Rozália Gold Mine, Hodruša-Hámre, Slovakia

Abstract

Microorganisms actively participate in biogeochemical cycles of various elements in the environment, including gold. To explore the core microbiota associated with gold ore, this study examined the bacterial composition of mined rock from the Rozália gold mine (two subsurface samples from the gold mine and one from the heap of mined ore) using a cultivation approach. Cultivation analyses showed the occurrence of bacteria with colony forming units (CFU) ranging from 2.18 × 10⁵ to 3.16 × 10⁵ per 1 gram of dry ore material, and the data analysis indicates that the type of cultivation medium used significantly influences the observed biodiversity of cultivable bacteria. Cultivated members of the microbial community were identified using a combination of MALDI-TOF MS and 16S rRNA gene sequencing. The cultivable microbiota of gold-bearing ore samples was predominantly composed of the phylum Proteobacteria. Identification of 473 isolates revealed the presence of 4 dominant genera: Rhizobium, Microbacterium, Pseudomonas, and Acinetobacter, which together accounted for 89% of the gold ore-associated cultivated bacteria. These results are consistent with previous studies on the microbiota of gold mines and suggest that these genera constitute the core microbiota of gold ore.

Keywords:

• Gold ore
• mine
• diversity
• cultivable microbiota
• Proteobacteria

Acknowledgment

The authors gratefully acknowledge the Institute of Environmental Engineering (Faculty of Mining and Geology, VŠB TU Ostrava) for support in the chemical analysis.

Disclosure statement

The authors declare no competing interest with respect to the worked performed in the manuscript.

Additional information

Funding

This work was supported by the Slovak Grant Agency for Science VEGA under Grant No. 1/0229/17; and the Slovak Research and Development Agency [Grant No. DS-FR-19-0008].