Luca Tonietti, Mattia Esposito, Martina Cascone, Bernardo Barosa, Stefano Fiscale, Maria Teresa Muscari Tomajoli, Tomasa Sbaffi, Rosa Santomartino, Giovanni Covone, Angelina Cordone, Donato Giovannelli, Alessandra Rotundi

Acidithiobacillus ferrooxidans, a Gram-negative bacterium thriving in extreme acidic conditions, has emerged as a key player in biomining and bioleaching technologies thanks to its unique ability to mobilize, directly or indirectly, a wide spectrum of elements, such as Li, P, V, Cr, Fe, Ni, Cu, Zn, Ga, As, Mo, W, Pb, U, and its role in ferrous iron oxidation, A. ferrooxidans catalyzes the extraction of metals by generating iron (III) ions in oxic conditions, which are able to react with metal sulfides. This review explores the bacterium's versatility in metal mobilization, with a focus on the mechanisms involved and its encompassing role in the recovery of industrially-relevant metals from complex ores. The application of biomining technologies leveraging the bacterium's natural capabilities not only enhances metal recovery efficiency, but also reduces reliance on conventional, energy-intensive methods, aligning with the global trend towards more sustainable mining practices. However, its use in biometallurgical application poses environmental issues through its effect on the pH levels in bioleaching systems, which produce acid mine drainage that effluents in rivers and lakes adjacent to traditional and abandoned mines. This dual effect underscores its potential to shape the future of responsible mining practices, including potentially in space, and highlights the importance of monitoring acidic releases in the environment.