Adaptations of Aspergillus carbonarius to Simulated Space Conditions: Preparatory Studies for the space experiment RayPairNyx

Abstract

Filamentous fungi, such as Aspergillus, are among the predominant species detected on space stations, including the former Mir space station and the International Space Station. These fungal contaminations pose potential risks to space missions due to their capacity to biodegrade spacecraft materials and cause infections in immunocompromised astronauts. The RayPairNyx experiment aims to study the germination of radiation-stressed Aspergillus carbonarius in real microgravity conditions aboard the first flight of the Nyx capsule (The Exploration Company). This fungal species is a common crop pathogen and mycotoxin producer. Therefore, the experiment will help to understand the fundamental genetic and metabolic mechanisms in mould species and enhance safety during future space travel by evaluating the risks posed by food-borne pathogens in spaceflight environments. Preparations for the experiment involved comparing the eGFP-tagged A. carbonarius strain AC49, which will be used in the RayPairNyx experiment, with the wild-type strain DSM 872. The comparison focused on optimal growth conditions, pigment synthesis, and survival under simulated space conditions (desiccation, microgravity, UV-C radiation, X-ray radiation). Both strains demonstrated high resistance to radiation and desiccation and exhibited accelerated germination in simulated microgravity. The transformed strain's suitability for the RayPairNyx experiment was confirmed, and potential methods for omics-based post-flight analyses were investigated.