For the first time, biologists from the United States studied the genomes of microbes living on the International Space Station and found that they are most similar to bacteria living on the surfaces of walls and furniture in apartments, according to an article published in PeerJ magazine.
“The microbes on board the ISS are very similar to those bacteria that live on the surface of the body of its inhabitants, which, in general, is not surprising, given that the station's crew is the main carrier of these organisms. In general, we can say that the microflora of the ISS has a high species diversity, which is very good, as it says that it works and develops normally,”said Jenna Lang from the University of California at Davis (USA).
Relatively recently, Russian cosmonauts conducting a planned spacewalk have found "live" bacteria on the ISS skin, as well as quite viable spores of fungi and other microorganisms. This discovery has rekindled the debate about whether life could be brought to Earth from space, and whether living organisms can "travel" in a similar way between planets and even stellar systems.
Microflora of the station is of no less interest. Recent observations of the life of "space" microbes show that the work of many cellular systems of bacteria changes greatly under conditions of weightlessness. This, coupled with the weakening of immunity in space, raises concerns that the entry of pathogenic microbes on board the ISS could cause serious health problems for the station's crew.
Lang and her colleagues conducted the first "population census" among microbes living on the ISS, enlisting the support of members of the 39th expedition - astronauts Steve Swanson and Rick Mastrakchio, as well as Russian cosmonauts Mikhail Tyurin, Alexander Skvortsov and Oleg Artemiev, and the station commander, a Japanese Koichi Wakata.
Before being sent into space, scientists gave cosmonauts and astronauts special sets of cotton swabs, flasks and cameras, with which they had to take samples from 15 different objects and surfaces in the American module "Harmony" and in the adjacent NASA laboratory. Some of them, for example, the walls of the stations and ventilation openings, rarely came into contact with the ISS crew, while others, such as pillows, microphones and door handles, constantly interact with humans.
When these samples were frozen and delivered to Earth, scientists extracted microbes from them, multiplied them and deciphered part of their DNA, counting the number of representatives of different types of fungi, bacteria and other inhabitants of the microworld. The scientists compared these data with the results of observations of microbes living in apartments and houses, which were carried out as part of the project to study the human microbiome and the initiative "Wildlife of Our Homes".
As shown by these measurements, the "space" bacteria were generally similar to their terrestrial relatives - they had a similar species composition and the number of microbes in general was quite high. Such results of the "census" surprised scientists, since they did not expect to see that on the ISS, where microbes never get from the "external" environment, there is an equally rich and large set of bacteria as in ordinary apartments, where they can safely penetrate from the street.
Promotional video:
“On Earth, we are surrounded by countless innocuous microbes, and we found about the same community of bacteria on board the ISS. This is not to say that the microbes from the ISS are more harmful than the typical bacteria from your living room,”concludes Jonathan Elsen, Lang's university colleague.