In-situ resource utilization and biomining of regolith by filamentous fungi. - Exploring fungi to help establish resource - efficient space missions

Abstract

With the prospect of human colonization on celestial bodies such as the Moon and Mars, the sustainability of space missions is of greater relevance and immediacy. Filamentous fungi are powerful microorganisms for biotechnological applications. As fungi require little resource input and are tolerant towards extreme environmental conditions, it is only logical to consider them for in-situ resource utilization (ISRU) applications in space research. However, these great characteristics not only offer potential but also pose a threat, as they are very likely to interact with and corrode even copper surfaces. This must be considered for future missions to Mars and the Moon. On one hand, the damage that can be done to spaceships needs to be minimized, and on the other hand, this offers the opportunity to establish sustainable mining applications, as these bodies are abundantly covered with regolith and offer a great source for ore retrieval, which is especially important since resupply missions are expensive. A study by Figueira et al. (2025) demonstrated the suitability of Penicillium simplicissimum for biomining the European Astronaut Centre Lunar Regolith Simulant (EAC-1A). The presented study explores both of the described scenarios. First, we aim to understand the process at the interface between Aspergillus species and metals under different gravity conditions. Here, we were able to show that the corrosive potential of Aspergillus species changes in simulated microgravity conditions and differs depending on the presence of different metal alloys, as they are corroded to different extents. Secondly, this study uses P. simplicissimum, alongside two Aspergillus species as reference strains, to compare their biomining efficiency to environmental fungi isolated from a moon analogue site in the Eifel region in Germany. With this, we aim to determine the most suitable candidates for future biomining approaches. Additionally, we want to understand the involved metabolic pathways and will identify upregulated genes in the best-performing strains to optimize and upscale the biomining process. Here, we showed that our fungal species are capable of growing under simulated microgravity conditions, as well as in the presence of Lunar Highland Simulant 1 (LHS-1). Additionally, we demonstrated that fungi can extract minerals and metals from LHS-1. The analysis of precipitated metals, as well as ICP-MS analysis of the leachate, showed that several metals were dissolved in the liquid phase. In general, our results were similar to those demonstrated by Figueira et al. (2025), which focused on the EAC-1A regolith. Although fungal bioleaching was demonstrated in general, it seems to be affected by several factors. This needs to be addressed in future research. Especially, the interaction between the fungus and the regolith in a bioreactor must be investigated to develop a tech demonstration with an optimized process to get one step closer to designing a novel ISRU technology. The suitability of microorganisms for biomining is well known. However, to date, only applications for bacteria have been studied extensively and industrially established. This study shows that fungi of the Aspergillus genus and other filamentous fungi are very promising candidates for ISRU applications in space.