Cleaning-resistant Cupriavidus and Ralstonia bacteria contaminating spacecrafts and the ultra clean rooms they are assembled in.

Background Planetary Protection is preventing microbial contamination of both the target planet and the Earth when sending spacecrafts on interplanetary space mission It is important to preserve the natural conditions of other planets and to not bring with robots earthly microbes forward contamination when looking for spores of extra terrestrial life Spacecrafts and the ultra clean rooms they are assembled in are routinely monitored for microbial contamination It was shown that the floor air and surfaces of such spacecraft assembly rooms often contain Cupriavidu s and Ralstonia bacteria These bacteria not only contaminated the clean rooms but have also been found prior-to-flight on surfaces of space robots such as the Mars Odyssey Orbiter La Duc et al 2003 and even in-flight in ISS cooling water and Shuttle drinking water unpublished Aim In this study several Cupriavidus and Ralstonia strains isolated from space craft assembling rooms and spacecrafts were characterized and analysed in detail Results The analysis showed that all the Cupriavidus and Ralstonia clean-room isolates are able to use a wide variety of substrates as carbon sources including ethanol and acetone In addition they all have accumulated moderate resistances to an extraordinary collection of physical and chemical antimicrobial agents Some of the test strains were able to form biofilms on plastic and metal materials used for space robots a nutritional and