Figure 1.

Phylogenetic tree, showing selected archaeal 16S rRNA genes from US American, European and South American spacecraft-associated clean rooms. The tree was calculated on the basis of the maximum likelihood methodology, implemented in the ARB software package (Ludwig et al., 2004). Sequences obtained from this study are shown in bold and highlighted (gray background). Sequences from previous studies are shown with gray background. Abbreviations: FR, Friedrichshafen; ES, ESTEC; KO, Kourou; SAF, spacecraft assembly facility at the Jet Propulsion Laboratory (Pasadena, CA, USA); JSC, Johnson Space Center (Houston, TX, USA).