NASA Finds Unknown Extremophile Stowaways

NASA builds its spacecraft in specialized, sterilized rooms in an effort to minimize contamination by airborne particles. Dust, along with its microbial passengers, could potentially impair instruments and render experiments invalid. For example, if scientists do find microbes on Mars, they will want to be very certain that they aren’t looking at hitchhikers from Earth that were somehow able to survive the inter-solar ride.

Gene sequencing is proving to be an effective means of detecting bacteria in these super-clean facilities as compared to previous monitoring methods. In fact, using the method, scientists not only found contaminants in the “sterilized” environment, but they even discovered a whole new species.

NASA clean rooms, where scientists and engineers assemble spacecraft, have joined hot springs, ice caves, and deep mines as unlikely places where scientists have discovered ultra-hardy organisms collectively known as ‘extremophiles’. Some species of bacteria uncovered in a recent NASA study have never been detected anywhere else on the planet.

According to Dr. Kasthuri Venkateswaran, who led the study conducted at NASA’s Jet Propulsion Laboratory in Pasadena, California, “These findings will advance the search for life on and other worlds both by sparking improved cleaning and sterilization methods and by preventing false-positive results in future experiments to detect .”

Clean rooms used in the space program already undergo extensive cleaning and air filtering procedures, and the detection technology employed in this study will help NASA to develop and monitor improvements. Still, it is extremely difficult to eliminate all dust particles and microbes without damaging the electronic instruments the process is intended to protect.

Identifying and archiving clean-room microbes could act as a sort of backup to cleaning and sterilization efforts. By comparing a list of microbes that could possibly stow away on its spacecraft, NASA can disregard them if they turn up in future Martian samples.

Venkateswaran’s team used a technology known as ribosomal RNA gene-sequence analysis to detect the bacteria found in clean rooms at Kennedy Space Center, Johnson Space Center, and the Jet Propulsion Laboratory. This was the first time that this technology has been applied to NASA clean rooms.

They found that both the total number of bacteria and the diversity of bacterial species were much higher than previously detected. This has implications not only for NASA and other space agencies, but also for hospital operating rooms and industries such as semiconductor manufacturing, where cleanliness and sterility are critical.

Clean rooms are very extreme environments for microbes because water and nutrients are in extremely short supply. Nevertheless, some bacteria are able to survive on what little moisture the low-humidity air provides and on trace elements in wall paint, residue of cleaning solvents, and in the spacecraft materials, themselves.

While not mentioned in the study, the possibility exists of accidentally contaminating the Martian surface with some of these extremophiles, especially as they are able to survive in incredibly harsh environments. If there are microbes living on Mars, a stowaway could potentially disrupt a delicate balance. On the other hand, if there are no living organisms on Mars—stowaways could theoretically change that.

Posted by Rebecca Sato

*This post was adapted from a news release issued by Blackwell Publishing.

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Links:

http://www.blackwell-synergy.com/doi/abs/10.1111/j.1574-6941.2007.00360.x

http://www.globalsecurity.org/space/library/news/2005/space-050726-2abd2287.htm

http://aerospacescholars.jsc.nasa.gov/HAS/cirr/em/10/10.cfm