Rare microbe found in clean room

A rare microbe that survives on very little to eat has been found in two places on Earth: spacecraft clean rooms in Florida and South America.

Extraterrestrial life, if found, would constitute a major discovery and would fundamentally change humanity’s understanding of the universe. Part of this search involves ruling out the possibility that potential “extraterrestrial” organisms were actually organisms from Earth that were accidentally transported to other worlds, and to prevent this, all spacecraft are subjected to severe cleaning measures. An organism surviving in the void of space after being subjected to the numerous chemical, physical and radiation treatments is highly unlikely; however, a bacterial strain has been found that exhibits these qualities.

In spacecraft cleanrooms in both Florida and French Guiana, scientists discovered and confirmed the presence of a novel bacterium, Tersicoccus phoenicis. While the conditions used to sterilize a cleanroom make it extremely difficult to survive, T. phoenicis nonetheless remained alive. While other bacteria have been found in cleanrooms, this is the first time that one like T. phoenicis has been found and independently characterized over such a wide geographical range.

Scientists working at the Jet Propulsion Laboratory in Pasadena, Calif. proposed that it constitutes a new genus, a higher order division on the tree of life. For example, humans (Homo sapiens) and Neanderthals (Homo neanderthalis) are part of the same genus but represent different species. In other words, T. phoenicisis as different from known bacteria as gorillas are from humans.

The distinction of a new genus came when scientists in French Guiana confirmed the same strain in a bacterial genomic database. Such a discovery, while novel, is also the result of systematic bias. For instance, the same organism could be present in low quantities in microbial communities all over the world, but only in highly circumstantial situations (such as those contrived by humanity) would it be able to constitute a dominant portion of a community.

T. phoenicis is proposed to be an organism that thrives on little-to-no nutrients; a similar organism, Paenibacillus phoenicis, also found in clean rooms, was found deep underground in a molybdenum mine. Current efforts include characterizing and sequencing the organism in hopes of regulating and eliminating the bacteria as part of standard cleaning procedures.

For results of extraterrestrial surveys to be accurate, we need to assure that any organisms we find indeed originate in the cosmos and are not just hitchhikers from earth. T. phoenicis also gives us the opportunity to figure out how to clean the most difficult and tenacious of organisms from our spacecraft, and minimize our galactic footprint.