A rare, recently discovered microbe that survives on very little to eat has been found in two places on Earth: spacecraft clean rooms in Florida and South America.
Microbiologists often do thorough surveys of bacteria and other microbes in spacecraft clean rooms. Fewer microbes live there than in almost any other environment on Earth, but the surveys are important for knowing what might hitch a ride into space. If extraterrestrial life is ever found, it would be readily checked against the census of a few hundred types of microbes detected in spacecraft clean rooms.
The work to keep clean rooms extremely clean knocks total microbe numbers way down. It also can select for microbes that withstand stresses such as drying, chemical cleaning, ultraviolet treatments and lack of nutrients. Perversely, microbes that withstand these stressors often also show elevated resistance to spacecraft sterilization methodologies such as heating and peroxide treatment.
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