Our manuscript, titled “Tersicoccus phoenicis (Actinobacteria), a spacecraft clean room isolate, exhibits dormancy,” published today in Microbiology Spectrum (ASM).
https://journals.asm.org/doi/10.1128/spectrum.01692-25
Spacecraft Cleanroom Bacterium Reveals a Survival Strategy with Implications from Orbit to Earth’s Food Industry.
What was discovered?
A bacterium called Tersicoccus phoenicis, isolated from NASA’s Kennedy Space Center spacecraft cleanroom, can enter a dormant, “Viable But Not Culturable” (VBNC) state under nutrient starvation. In this state, it becomes undetectable by standard culture methods, yet remains alive—and can be revived using a biochemical trigger known as a resuscitation-promoting factor (Rpf).
Why is this important?
Space agencies focus heavily on eliminating spore-forming microbes like Bacillus, which are known to survive harsh sterilization. This study, however, highlights the overlooked resilience of non-spore-forming microbes—like T. phoenicis—that persist by entering dormancy. These microbes may survive despite rigorous decontamination, posing a hidden challenge to planetary protection protocols.
Beyond space: parallels on Earth
Dormancy isn’t just a problem for spacecraft. Pharmaceutical cleanrooms, which manufacture sterile drugs and vaccines, have reported dormant Micrococcus luteus—a close relative of T. phoenicis—lurking on surfaces and protective garments. These dormant cells can evade detection, only to revive under favorable conditions, potentially compromising product sterility.
Similarly, in the food industry, dormant bacteria like Listeria monocytogenes and Vibrio parahaemolyticus can enter VBNC states in response to cold or chemical stress—then reactivate, raising food safety risks. Their ability to “hide” during routine quality checks presents a real challenge for detection and control.
Relevance to the ISS and other human-built habitats:
Microbes related to T. phoenicis have also been detected on spacesuits aboard the International Space Station (ISS), as well as in simulated Mars habitats. These enclosed, nutrient-poor, highly sanitized environments are known to unintentionally select for extremotolerant organisms that survive through dormancy rather than active growth.
Implications for astrobiology and extremophile survival:
Dormancy is likely an ancient survival strategy, shaped by early Earth conditions. If microbes like T. phoenicis can persist unseen in spacecraft environments, could they survive deep space travel etc?
Question: Planetary protection risks from dormant Earth microbes?
Key takeaway - In the cleanest places we build—spacecraft, pharma plants, food facilities—some microbes aren’t dead. They’re dormant.
