Cultivation, isolation and identification of extremophiles from monitored cleanroom environments

Kurzfassung

Bioburden controlled cleanrooms of different classes are very harsh environments for microorganisms due to their necessity to have a concentration as low as possible in germs as well as particles. Special air filtering, cleanable and smooth surfaces, strict cleaning with acidic and alkaline detergents, monitored and restricted excess and work by employees, contribute to the specific environment found in cleanrooms. In the scope of planetary protection monitoring campaigns, we conduct regular screenings of cleanroom facilities where spacecrafts and space hardware are built. This is necessary as extraterrestrial bodies of high interest for astrobiological research shall not be contaminated by human space exploration. During these campaigns samples are taken via wipes (1m²) or swaps (25cm²) and subsequently organisms that survive a heat shock treatment are being isolated and identified by an internationally agreed standard cultivation assay. Until now the regulations do not demand the cultivation and detection of species other than spore forming organisms. Here we present the approach to cultivate and identify extremophilic organisms that might also be present in cleanrooms. We focused on anaerobic, halophilic and oligotrophic organisms as well as organisms the show a higher resistance towards desiccation and UV irradiation. With this work we will develop additional isolation and identification methods to expand the current standard sampling and cultivation for planetary protection as well as provide data to the scientific community that will show weather or not current regulations regarding planetary protection need to be revised.