Space station biomining experiment demonstrates rare earth element extraction in microgravity and Mars gravity

Microorganisms are employed to mine economically important elements from rocks, including the rare earth elements (REEs), used in electronic industries and alloy production. We carried out a mining experiment on the International Space Station to test hypotheses on the bioleaching of REEs from basaltic rock in microgravity and simulated Mars and Earth gravities using three microorganisms and a purposely designed biomining reactor. Sphingomonas desiccabilis enhanced mean leached concentrations of REEs compared to non-biological controls in all gravity conditions. No significant difference in final yields was observed between gravity conditions, showing the efficacy of the process under different gravity regimens. Bacillus subtilis exhibited a reduction in bioleaching efficacy and Cupriavidus metallidurans showed no difference compared to non-biological controls, showing the microbial specificity of the process, as on Earth. These data demonstrate the potential for space biomining and the principles of a reactor to advance human industry and mining beyond Earth.

Charles S. Cockell, Rosa Santomartino, Kai Finster, Annemiek C. Waajen, Lorna J. Eades, Ralf Moeller, Petra Rettberg, Felix M. Fuchs, Rob Van Houdt, Natalie Leys, Ilse Coninx, Jason Hatton, Luca Parmitano, Jutta Krause, Andrea Koehler, Nicol Caplin, Lobke Zuijderduijn, Alessandro Mariani, Stefano S. Pellari, Fabrizio Carubia, Giacomo Luciani, Michele Balsamo, Valfredo Zolesi, Natasha Nicholson, Claire-Marie Loudon, Jeannine Doswald-Winkler, Magdalena Herová, Bernd Rattenbacher, Jennifer Wadsworth, R. Craig Everroad, René Demets