Editorial: The impact of the space environment on microbial growth and behavior

Microorganisms play an important role in life and can adapt to and survive in harsh and changing environments. Their ability to thrive in hostile conditions is reflected not only by their survival and activity in Earth's most extreme environments but also in low Earth orbit (LEO) and outer space (Olsson-Francis et al., 2018; Thombre et al., 2022). Spaceflight and the space environment present unique stressors compared to Earth (microgravity, galactic cosmic radiation, solar UV radiation, space vacuum, thermal extremes) to which microbes are exposed, but how they adapt and respond, especially in the context of deep-space exploratory missions, is still poorly understood (Tesei et al., 2022). Studies to date, though, have shown that these responses can range from being beneficial for human exploration—such as potential applications in biological life support systems (BLSS), in situ resource utilization (ISRU) and astronaut therapeutics (Koehle et al., 2023)—to negatively impact long duration missions (e.g., biofilm formation, increased virulence, and reduced susceptibility to antimicrobial agents), which pose risks to astronaut's health and spacecraft integrity (Wilson et al., 2007; Kim et al., 2013; Urbaniak et al., 2018). Hence, investigating the reaction of microorganisms to space conditions and the alterations in their physiology, not only helps to shed light on the molecular basis of tolerance, but also holds implications for both space exploration and astrobiology missions. This Research Topic features published articles pertaining to microbial adaption under spaceflight or simulated Mars conditions (Puig et al., Averesch et al., Blachowicz et al., Fagliarone et al., Gesztesi et al., Muñoz-Hisado et al.), life in extreme environments on Earth (Moors et al.) and planetary protection (Stott et al., Dean et al., Seto et al., Mogul et al., Kimura et al.).