Van Rossum, T & Gurieff, NB 2025, 'Mine site microbes for remediation and metal recovery', in S Knutsson, AB Fourie & M Tibbett (eds), Mine Closure 2025: Proceedings of the 18th International Conference on Mine Closure, Australian Centre for Geomechanics, Perth, pp. 1-12, https://doi.org/10.36487/ACG_repo/2515_62
(https://papers.acg.uwa.edu.au/p/2515_62_Van Rossum/)
Abstract: Over several decades, a select few microbes have been discovered that can release metals from mine waste (bioleach), detoxify contaminants, and neutralise acidic environments. These microbes have been employed in open and contained facilities up to industrial scales. However, their functional efficiencies vary and introducing foreign microbes into new environments can pose unexpected risks. Mine sites are naturally home to millions of microbes, some of which are primed to efficiently perform these functions under local conditions, presenting opportunities to maximise metal recovery while minimising environmental impact from current and legacy mining activities. Until recently, discovering local microbes at scale has been cost-prohibitive. Using advanced DNA sequencing and computation via the mining microbiome analytics platform (M-MAP), we profiled hundreds of mine site samples. We recovered genomes from over 1,600 native microbial strains, revealing their functional potential, including sulphur and iron oxidation or reduction, and copper immobilisation or transport. This data also provides important information on how to enhance the growth of selected microbial strains, including energy and nutritional sources as well as optimal ranges for temperature and acidity. By integrating DNA information with chemical information from the same source samples, we can identify microbial strains with key traits required for efficient biomining and bioremediation. For example, we identified a tractable set of 33 strains, which can now be advanced to lab-scale technology development. Similarly, we can apply this approach to discover strains with potential application in tailings stabilisation, acid mitigation, and contaminant removal. This microbial inventory is supported by biobanked source samples enabling iterative biotechnological research. This work supports the development of innovative microbial solutions that enhance operational efficiencies and drive sustainability objectives across Rio Tinto’s mining operations. 

Keywords: bioremediation, biocementation, MICP, bioleaching, bacteria,