Microorganisms (or "Hungry Miners" as we call them) that are currently used in commercial bioleaching operations are so far ubiquitous in nature. Wherever a suitable ore is exposed to the hungry miner and water is present, the naturally occurring microorganisms (MOs) will be found exploiting the resource.
The first isolated and best-studied iron and/or sulfur-oxidizing bacterium is Acidithiobacillus ferrooxidans, formerly known as Thiobacillus ferrooxidans. The perceived importance of At. ferrooxidans in bioleaching environments was largely a consequence of the relative ease of its enrichment and isolation, and its rapid growth in acidic iron(II) media, by which it out-competed other members of its microbial community (Watling, H. 2016). The discovery and description of this miner prompted a rapid increase in microbiological studies related to the oxidation of sulﬁde minerals.
HOWEVER - the growth of above-given miners is inhibited or prevented in the presence of organic matter. Therefore the efficiency of bioleaching an ore where metals are trapped in organic complexes is not maximum. The microorganisms also only function in specific temperature ranges, require iron or reduced sulfur as an energy source and in most cases grow optimally at pH < 2.5.
Luckily, the team of Hungry Miners developed in BiotaTec operate best at neutral pH and do excellent work in breaking up organic complexes (porphyrin rings) while simultaneously producing methane gas and freeing metals into the water solution. They also turn toxic sub-products of methanogenesis (NH3, H2, H2S) into non-hazardous products (N2, H2O, S0).
Peer-reviewed publication about this amazing team is being prepared - stay tuned:-)!