November 7, 2013
NASA, ESA Spacecraft Clean Rooms Infested With Rare Bacterium
Lee Rannals for redOrbit.com - Your Universe Online
Fewer microbes live in a spacecraft clean room than in almost any other environment on Earth. Surveys of what might be living in these clean rooms are important for understanding what could be hitching a ride into space.
If scientists were ever to discover extraterrestrial life then it would be readily checked against the census of a few hundred types of microbes detected in spacecraft clean rooms in order to determine whether it is actually a discovery or just contamination.
NASA said microbes that are found inside these clean rooms are able to withstand stressors like drying, chemical cleaning, ultraviolet treatment and lack of nutrients. They are also able to withstand spacecraft sterilization methodologies like heating and peroxide treatment.
"We want to have a better understanding of these bugs, because the capabilities that adapt them for surviving in clean rooms might also let them survive on a spacecraft," stated microbiologist Parag Vaishampayan, of NASA's Jet Propulsion Laboratory, Pasadena, California. "This particular bug survives with almost no nutrients."
The space agency said that this new microbe, known as Tersicoccus phoenicis, is different from any other known bacteria. The berry-shaped bacterium has been classified as both a new species and a new genus.
Other microbes have also been discovered in a spacecraft clean room and found nowhere else on Earth. However, none of these other microbes have been discovered in two different clean rooms and nowhere else. The Tersicoccus phoenicis microbes were found 2,500 miles apart in a NASA facility at Kennedy Space Center and a European Space Agency facility in Kourou, French Guiana.
A global database shows that the microbe has not been detected in any other location, which did not surprise Vaishampayan.
"We find a lot of bugs in clean rooms because we are looking so hard to find them there,” said Vaishampayan, lead author of the paper on the microbe, published in International Journal of Systematic and Evolutionary Microbiology. “The same bug might be in the soil outside the clean room but we wouldn't necessarily identify it there because it would be hidden by the overwhelming numbers of other bugs."
A teaspoon of soil might contain thousands of types of microbes and billions more total microbes than an entire clean room. Over 99 percent of bacterial strains have never been cultivated in laboratories, which is a necessary step for characterizing a strain of a new species.
Microbes that are tolerant of harsh conditions could become more evident in clean room environments that remove the rest of the bacteria. Vaishampayan says that Tersicoccus phoenicis could be found in some natural environments with extremely low nutrient levels.
Scientists will continue to study the microbe in order to help them understand possible ways to control it in spacecraft clean rooms and fully sequence its DNA.