Space Microbes: New Bacteria Discovered on China’s Tiangong Space Station

In May 2023, the Chinese astronauts discovered a new type of bacteria, named Niallia tiangongensis, inside a cabin of the Tiangong space station. The finding of this bacterium raises important questions about its potential to evolve, survive and grow in extreme conditions of space. The discovery of Niallia tiangongensis plays a vital role as it highlights not only the presence of previously unknown bacteria but also the importance of studying the characteristics to keep the space travelers safe.

Discovery

To investigate its origin, a research team conducted further sampling. As part of China Space Station Habitation Area Microbiome Program(CHAMP), the team of Shenzhou-15 collected the swab samples from the space station. These samples were then frozen. The preserved frozen samples were returned back to Earth for detailed genetic analysis.

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A study in the Journal of Systematic and Evolutionary Microbiology reported the identification of a bacterial species from space station samples, classified under the genus Niallia. Genomic sequencing indicated its closest known terrestrial relative was Niallia circulans, with notable genetic differences observed in the Tiangong strain.

Characteristics

Niallia tiangongensis is a rod-shaped, spore-forming and aerobic bacteria that grows in soil. It is closely related to Niallia circulans, a bacteria which naturally occurs in soil. Niallia tiangongensis typically causes sepsis primarily in immunocompromised individuals. However, it was found inside the space station, and its characteristics are not yet fully understood.

The adaptation of bacteria is influenced by the external environment. Their functioning may vary under different conditions for example bacterial activity on earth significantly differs from that in space. This variation is due to the influence of several factors including microgravity, exposure to radiation, nutrient availability and reproductive conditions. Studies have shown that some bacteria grow faster and have relatively thick cell walls in space. However, it is not clear whether Niallia tiangongensis undergoes similar changes.

Genetic Features

Niallia tiangongensis possesses recombinant genes associated with oxidative stress response. It also has a DNA repair mechanism and is coated by a protective covering of biofilm which protects it. The enzyme in Niallia tiangongensis breaks down gelatin, a nutrient source, and provides nutrients for itself when the food is insufficient.

Astronauts Health Concerns

It is a significant discovery because it demonstrates that bacteria can survive in the extreme environment of space. This raises concerns about astronauts’ health, especially for those on prolonged space missions. It also emphasizes the importance of maintaining cleanliness and sanitation at space stations. Overall, this discovery supports the idea that life can survive beyond earth, and it paves the way for more promising research and mission in the future.

The detection of Niallia tiangongensis also raises another concern regarding the protection of celestial bodies and space stations. As space exploration expands beyond a few planets, humans continue to investigate various extraterrestrial environments. This increases the risks of transferring Earth originating microbes to other planets or bringing unknown organisms back to Earth. Therefore, it is essential to implement strict planetary protection measures to prevent backward and forward contamination.

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For further space exploration and missions, protection against microbial threats is crucial. Bacteria and other microorganisms can interact, adapt and mutate rapidly in space due to microgravity and radiation exposure. Studying these changes is essential to ensure the health and safety of astronauts and the integrity of space missions.