The Isolation and Characterization of Rare Mycobiome Associated With Spacecraft Assembly Cleanrooms

Area of Science:

• Microbiology
• Astrobiology
• Planetary Protection

Background:

• NASA Planetary Protection policies have historically focused on bacterial endospores, neglecting fungal contamination in spacecraft assembly.
• Ensuring biological cleanliness is critical for robotic exploration of the solar system to prevent forward contamination of celestial bodies.

Purpose of the Study:

• To characterize the viable mycobiome of spacecraft assembly facilities at JPL and KSC for the first time.
• To assess fungal populations as potential biocontaminants in interplanetary exploration.
• To inform future planetary protection strategies regarding fungal contamination.

Main Methods:

• Cultivation and amplicon sequencing techniques were employed to assess fungal populations.
• Samples were treated with chloramphenicol and propidium monoazide (PMA) to enumerate viable fungi.
• Network analysis was used to visualize fungal biogeography and abundance.

Main Results:

• 28 distinct cultivable fungal species were identified, with 13 potentially novel; only four species were common to both JPL and KSC.
• Mycobiomes differed significantly between the two facilities, with variations in fungal abundance observed after antibiotic treatment.
• Ascomycota (91%) and Basidiomycota (7.15%) dominated metagenomic fungal reads.

Conclusions:

• Spacecraft assembly facility mycobiomes are geographically distinct and influenced by factors like location and cleaning procedures.
• This study provides a foundational characterization of viable fungi in cleanrooms, essential for refining planetary protection protocols.
• Findings have broader implications for microbial control in other sensitive environments, such as healthcare and industrial cleanrooms.