Mysterious Space Bacteria Discovered on China’s Tiangong Station By David Freeman - May 21, 2025
In the cold vacuum of space, orbiting hundreds of kilometers above Earth, something unknown has been growing aboard China’s Tiangong Space Station. Scientists have identified a completely new strain of bacteria that has never been seen on our planet.
The microorganism, named Niallia tiangongensis after the space station where it was found, shows unusual characteristics distinct from Earth bacteria. This finding comes from samples collected in 2023 by the Shenzhou-15 mission crew, who methodically swabbed surfaces within the station’s cabin.
These samples, frozen and returned to Earth, underwent analysis by researchers from the Shenzhou Space Biotechnology Group and the Beijing Institute of Spacecraft System Engineering as part of the China Space Station Habitation Area Microbiome Programme. Their research, published March 3, 2025, in the International Journal of Systematic and Evolutionary Microbiology, confirms this space-dwelling organism exists nowhere on Earth.
“Strain JL1B1071T was isolated from the surface of hardware on the China Space Station,” states the research paper. The scientific team determined this wasn’t merely a known bacteria that hitchhiked to space but a novel species with distinct genetic and functional differences from any known terrestrial microbes.
This rod-shaped, spore-forming bacteria relates to Niallia circulans, a soil-dwelling microorganism found in ground soil, sewage, and food products on Earth. However, genetic analysis showed major differences. The genome of Niallia tiangongensis measures 5,166,230 base pairs with a G+C content of 35.6 mol%, creating a genetic fingerprint unlike anything in our microbial databases.
Comparing the space strain to its closest Earth relative, scientists found the average nucleotide identity and digital DNA-DNA hybridization values were 83.3% and 27.5% respectively—both far below the thresholds used to determine whether organisms belong to the same species. This confirms the Tiangong station hosts a genuinely new life form.
Space agencies worldwide worry about microbial contamination in space habitats. Despite cleaning protocols and sterilization procedures, microscopic life survives and adapts. NASA previously identified multiple bacteria strains aboard the International Space Station, including some with antibiotic resistance.
The Tiangong bacteria has adapted to spaceflight stresses. Microgravity, increased radiation, and limited nutrients create selection pressures that drive rapid evolution in microorganisms.
The China Space Station Habitation Area Microbiome Programme tracks microbe growth within the space station since its launch. This monitoring allows researchers to observe changes in the station’s microbial population over time, showing how living organisms adapt to space conditions.
“Understanding the characteristics of microbes during long-term space missions is essential for safeguarding the health of astronauts and maintaining the functionality of spacecraft,” the researchers wrote.
The Tiangong Space Station, launched April 2021, serves as China’s permanent outpost in low Earth orbit. The modular station consists of three modules and remains continuously inhabited by rotating crews of Chinese astronauts. Like all human habitats in space, it creates an artificial ecosystem where Earth microbes establish colonies and evolve.
Niallia tiangongensis comes from a recently reclassified group of bacteria. Its Earth relative, Niallia circulans, was until recently categorized as a form of Bacillus, a common bacteria genus found throughout nature. The reclassification and now this space-adapted variant discovery points to gaps in our understanding of microbial adaptation.
The physical characteristics of the new bacteria include a Gram-positive cell wall structure and an aerobic metabolism, requiring oxygen to survive. Its ability to form spores—tough protective shells around its genetic material—allows survival in harsh conditions that kill other microorganisms, making it well-suited for the challenging environment of space.
Researchers now study this organism to determine when and how it diverged from Earth bacteria. Did it arrive on the station in its current form, or did it evolve these adaptations during its time in orbit?
Scientists have long known that bacteria can adapt rapidly to new environments on Earth. Now we’re watching this process unfold in real-time beyond our planet.
The most notable adaptation of Niallia tiangongensis is its unique ability to break down gelatin. This capability allows the bacteria to extract carbon and nitrogen from its surroundings, forming protective biofilms that shield it from the harsh conditions of space. The microbe has developed specific genetic traits to handle oxidative stress and repair radiation damage—essential survival skills for life outside Earth’s protective atmosphere.
“Genomic analysis of JL1B1071T revealed two conserved signature indels in the GAF domain-containing protein and DNA ligase D protein, which are specific to the genus Niallia,” according to the research paper. “Additionally, structural and functional differences in proteins BshB1 and SplA were identified, which may enhance biofilm formation, oxidative stress response and radiation damage repair, thereby aiding its survival in the space environment.”
These genetic adaptations point to the remarkable ability of life to modify itself when faced with extreme conditions. While Earth bacteria often compete with countless other microorganisms for resources, the relatively sterile environment of a space station allows certain hardy species to thrive without competition.
The discovery raises important questions about protecting astronauts during long-duration space missions. If Niallia tiangongensis evolved from a strain similar to Niallia circulans, which can cause sepsis in people with weakened immune systems, could this space-adapted variant pose health risks? The researchers haven’t yet determined whether the new species threatens human health, but the question demands investigation.
This isn’t the first time unexpected microbial life has been found in supposedly sterile space environments. In 2018, NASA scientists discovered four previously unknown strains of antibiotic-resistant bacteria hiding inside the International Space Station’s toilets. Each strain showed special adaptations for surviving in space.
Even more surprising, NASA found 53 strains of bacteria inside the “clean rooms” used to prepare the Phoenix Mars Lander, including 26 previously unknown species. These findings suggest that no matter how strict the sterilization protocols, microscopic hitchhikers find ways to survive and adapt.
Some scientists have even proposed investigating whether bacteria might survive on the exterior of space stations, exposed directly to the vacuum of space. Such extreme survivors would push the boundaries of what we consider possible for life.
The challenge of controlling microbial growth becomes more pressing as both China and NASA work toward establishing permanent bases on the Moon. In the confined quarters of a space station or lunar habitat, infections can spread rapidly among crew members. If novel, antibiotic-resistant bacteria develop within these closed systems, they could pose serious health risks to astronauts far from Earth’s medical facilities.
NASA research suggests that the sterile environment of space stations might actually increase certain health risks. A recent study found that the absence of competing bacteria allowed skin germs from astronauts to thrive unchecked on station surfaces, potentially leading to more skin rashes and cold sores among crew members.
As we venture farther from Earth for longer periods, managing these microbial risks becomes crucial. The tiny, invisible passengers we unknowingly carry with us into space may ultimately become one of the greatest challenges to long-term human habitation beyond our home planet.
The study of Niallia tiangongensis represents more than just a scientific curiosity—it provides a window into the future of human space exploration and the unexpected ways life adapts to environments never experienced in its evolutionary history. As we continue to push the boundaries of human presence in space, we must accept that we never truly travel alone. Microscopic life forms accompany us, changing and adapting in ways we are only beginning to understand.
The major fatty acids found in Niallia tiangongensis were anteiso-C15:0 and iso-C15:0, while its main quinone was menaquinone-7 (MK-7)—biochemical details that help scientists place it precisely in the microbial family tree. These chemical markers, combined with its genetic sequence and physical characteristics, allowed the research team to classify it as a new species within the Niallia genus.
The bacteria has been preserved in two culture collections: the Guangdong Microbial Culture Collection Center (GDMCC 1.4642) and the Korean Collection for Type Cultures (KCTC 43715). These preserved samples will allow scientists worldwide to study this unique organism and learn from its adaptations to the space environment.
As we consider the implications of this discovery, one fact becomes increasingly clear: wherever humans go, life finds a way to follow and adapt. Our journey into space isn’t just a human endeavor—it’s a biological one, with consequences and possibilities we’re still learning to predict. The microbes that accompany us on this journey may develop in ways we never anticipated, creating new forms of life unique to the environments we create beyond Earth.
The study of space-adapted microorganisms like Niallia tiangongensis will be essential as humanity extends its reach into the solar system. Understanding how life changes in response to space conditions may help us protect astronaut health, maintain spacecraft functionality, and perhaps even harness these organisms’ unique abilities for our benefit in the harsh frontier of space.
Source:
Yuan, J., Zhang, W., Dang, L., Song, Y., Yin, Z., He, Z., Xu, K., Guo, P., & Yin, H. (2025). Niallia tiangongensis sp. nov., isolated from the China Space Station. International Journal of Systematic and Evolutionary Microbiology. Published March 3, 2025. https://doi.org/10.1099/ijsem.0.006693 ChristopherBlackwell
Oh wonderful. Something else for China to mess with and accidentally release into the wild to kill
us all, or at least millions of unsuspecting people.
I get it that we need to understand these things to expand from being earthbound, but set up labs in space, NOT here on earth where accidental release COULD kill everyone.
on May 21, 2025, 8:38 pm
