RESUMO
A census of clean room surface-associated bacterial populations was derived from the results of both the cloning and sequencing of 16S rRNA genes and DNA microarray (PhyloChip) analyses. Samples from the Lockheed Martin Aeronautics Multiple Testing Facility (LMA-MTF), the Kennedy Space Center Payload Hazard and Servicing Facility (KSC-PHSF), and the Jet Propulsion Laboratory Spacecraft Assembly Facility (JPL-SAF) clean rooms were collected during the various assembly phases of the Phoenix and Mars Science Laboratory (MSL) spacecraft. Clone library-derived analyses detected a larger bacterial diversity prior to the arrival of spacecraft hardware in these clean room facilities. PhyloChip results were in agreement with this trend but also unveiled the presence of anywhere from 9- to 70-fold more bacterial taxa than cloning approaches. Among the facilities sampled, the JPL-SAF (MSL mission) housed a significantly less diverse bacterial population than either the LMA-MTF or KSC-PHSF (Phoenix mission). Bacterial taxa known to thrive in arid conditions were frequently detected in MSL-associated JPL-SAF samples, whereas proteobacterial lineages dominated Phoenix-associated KSC-PHSF samples. Comprehensive bacterial censuses, such as that reported here, will help space-faring nations preemptively identify contaminant biomatter that may compromise extraterrestrial life detection experiments. The robust nature and high sensitivity of DNA microarray technologies should prove beneficial to a wide range of scientific, electronic, homeland security, medical, and pharmaceutical applications and to any other ventures with a vested interest in monitoring and controlling contamination in exceptionally clean environments.
Assuntos
Bactérias/genética , Bactérias/isolamento & purificação , Clonagem Molecular/métodos , Ambiente Controlado , Análise de Sequência com Séries de Oligonucleotídeos/métodos , Bactérias/classificação , Sequência de Bases , Biodiversidade , Primers do DNA/genética , DNA Bacteriano/genética , Microbiologia Ambiental , Meio Ambiente Extraterreno , Genes Bacterianos , Dados de Sequência Molecular , Filogenia , RNA Bacteriano/genética , RNA Ribossômico 16S/genética , Voo Espacial , Estados Unidos , United States National Aeronautics and Space AdministrationRESUMO
We consider the aseptic assembly of the Beagle 2 Mars probe and how the requirements of COSPAR planetary protection category IVa were achieved. Several areas for future investigation became apparent. An ESA mission is outlined in which a microbial bioburden is recovered after Earth orbit to assess viability following re-entry through the atmosphere.
