Swabs taken from Chinese Space Station Tiangong In 2023 they revealed the presence of a bacterium not yet known which could have unique characteristics to survive in environmental conditions far from the surface of the earth. The name has been attributed to the microorganism Nialia tianggensis For two reasons: its classification in the kind of gram-positive bacteria Nialia And the call to the Tiangong space station. There are still few news about this “new species”, has a relative who lives on earth (Nialia Circulans), but it is not yet clear whether it has evolved in the space of the Solar System or has arrived there as a spora, nor if it represents a risk to human health. The study on the bacterium, published in the magazine International Journal of Systematic and Evolutionary Microbiology by the researchers of the Shenzhou Space Biotechnology Group and the Beijing Institute of Spacecraft System Engineering, could reveal the molecular causes of adaptation to space, such as the ability to form biofilmrespond to oxidative stress and efficiently repair radiation damage.
The characteristics of the bacterium Nialia tianggensis discovered in the space station
The authors of the study, the result of an investigation conducted by China Space Station Habitation area microbiome program programsay that understanding the characteristics of the microorganisms that populate the space stations is essential for the health of astronauts and for preserve the function of the stations. In the case of the new strain found by the Shenzhou-15 crew in May 2023, the research revealed that it is a bacterium:
- Gram-positive: its thick cell wall retains the purple coloring of Gram, used in the microbiological test to classify the bacteria in the two large grams and gram negative grams categories (do not hold back the dye)
- Aerobic: requires oxygen to grow
- Sporiferous: it is able to form spore resistant to adverse environmental conditions such as extreme heat, radiation and lack of nutrients. These structures can remain vital for long periods and “come to life” when the conditions improve
- Sticker: bacteria with this elongated form are commonly called bacilli.
This species seems to have a close relative on earth, Nialia Circulansa bacterial strain that lives in landonly recently classified in the genre Nialia and first recognized in the genre Bacillus because of the form. In the case of Circulasalso a sportigenum, cases of infections and sepsis in humans have been documented, ability not yet known for Nialia tianggensis.
What makes the bacterium unknown suitable for survival in space
The analysis of the function of its gene revealed the unique ability of the “spatial” strain of using the jellyvery complex protein derived from collagen, as a source of nitrogen And carbonuseful for taking refuge under a protective layer of biofilm in complicated conditions. When it comes to biofilm we mean a Aggregate of microbes included in one biopolymeric matrix made up of sugars, proteins and other molecules they produce. This “shield” protects bacteria and other microorganisms in hostile environments and also has a role inantibiotic-resistancea big problem globally that makes pathogenic bacteria “immune” to drugs.
In addition to the use of Biofilm, the study showed molecular characteristics which could improve the response to oxidative stress and the repair of radiation damagethus favoring its survival of this microorganism in space.
