AUTHOR=Cockell Charles S. , Santomartino Rosa , Finster Kai , Waajen Annemiek C. , Nicholson Natasha , Loudon Claire-Marie , Eades Lorna J. , Moeller Ralf , Rettberg Petra , Fuchs Felix M. , Van Houdt Rob , Leys Natalie , Coninx Ilse , Hatton Jason , Parmitano Luca , Krause Jutta , Koehler Andrea , Caplin Nicol , Zuijderduijn Lobke , Mariani Alessandro , Pellari Stefano , Carubia Fabrizio , Luciani Giacomo , Balsamo Michele , Zolesi Valfredo , Ochoa Jon , Sen Pia , Watt James A. J. , Doswald-Winkler Jeannine , Herová Magdalena , Rattenbacher Bernd , Wadsworth Jennifer , Everroad R. Craig , Demets René TITLE=Microbially-Enhanced Vanadium Mining and Bioremediation Under Micro- and Mars Gravity on the International Space Station JOURNAL=Frontiers in Microbiology VOLUME=12 YEAR=2021 URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2021.641387 DOI=10.3389/fmicb.2021.641387 ISSN=1664-302X ABSTRACT=

As humans explore and settle in space, they will need to mine elements to support industries such as manufacturing and construction. In preparation for the establishment of permanent human settlements across the Solar System, we conducted the ESA BioRock experiment on board the International Space Station to investigate whether biological mining could be accomplished under extraterrestrial gravity conditions. We tested the hypothesis that the gravity (g) level influenced the efficacy with which biomining could be achieved from basalt, an abundant material on the Moon and Mars, by quantifying bioleaching by three different microorganisms under microgravity, simulated Mars and Earth gravitational conditions. One element of interest in mining is vanadium (V), which is added to steel to fabricate high strength, corrosion-resistant structural materials for buildings, transportation, tools and other applications. The results showed that Sphingomonas desiccabilis and Bacillus subtilis enhanced the leaching of vanadium under the three gravity conditions compared to sterile controls by 184.92 to 283.22%, respectively. Gravity did not have a significant effect on mean leaching, thus showing the potential for biomining on Solar System objects with diverse gravitational conditions. Our results demonstrate the potential to use microorganisms to conduct elemental mining and other bioindustrial processes in space locations with non-1 × g gravity. These same principles apply to extraterrestrial bioremediation and elemental recycling beyond Earth.