OTU heatmap.

<p>based on taxa, which are part of the respective core microbiome from CCR (controlled cleanroom) and UAF (uncontrolled adjoining facility). Color code from blue via white to red (0–50–100%) gives relative amount [%] of respective taxonomic group. Table was rarefied to 3406 OTUs (CCR samples), and 6665 OTUs (UAF samples). Table was sorted according to resulting P-values (p) of an ANOVA test (significant (p) at an alpha of 0.05 are highlighted in bold). (p) were corrected with false discovery rate (fdr (p)) and bonferroni (bonf. (p)). Samples treated with PMA prior to DNA extraction are indicated by a plus symbol.</p

Core OTU network

<p>(spring embedded eweighted) of CCR (red), CCR+ (orange), UAF (blue) and UAF+ (green) samples. Node size represents OTU abundance and edge width and opacity is weighted. OTUs resolved to genus level are highlighted and font size correlates with OTU abundance. Bacterial genera in red represent potential spore formers. Samples treated with PMA prior to DNA extraction are indicated by a plus symbol. CCR: controlled cleanroom. UAF: uncontrolled adjoining facility.</p

Summary of the microbial abundance and diversity detected in the spacecraft assembly cleanroom (controlled cleanroom–CCR) at NASA Jet Propulsion Laboratory, Pasadena, CA, USA and its surrounding uncontrolled adjoining facility—UAF.

<p>(Numbers for quantitative measures are given per m²).</p

Beta-diversity (unweighted).

<p>(A) NMDS plot based on unweighted (left) unifrac distance matrix of rarefied OTUs to 10,011 sequences. Samples treated with PMA prior to DNA extraction are indicated by a plus symbol. CCR: controlled cleanroom. UAF: uncontrolled adjoining facility. Variances are explained per each axis (NMDS1 and NMDS2, Stress = 0.06). (B) Distance based comparison heatmap combined with a hierarchical cluster analysis based on average neighbor (HCAN) of unweighted unifrac distances. Dissimilarity of samples is indicated by a color gradient from blue (similar) via white to red (dissimilar). Samples treated with PMA prior to DNA extraction are indicated by a plus symbol. CCR: controlled cleanroom. UAF: uncontrolled adjoining facility.</p

Quantitative evaluations.

<p>of controlled cleanroom (CCR) and uncontrolled adjoining facility (UAF) per square meter floor surface. Upper panel shows ATP counts for total (grey bars) and intracellular ATP (black bars) in CCR and UAF (total and intracellular ATP was determined in duplicate). Lower panel shows 16S rRNA gene copies in CCR and UAF with (black bars)–and without (grey bars) PMA (propidium monoazide) treatment in triplicate (error bars represent positive and negative standard deviations).</p

Influence of embedding in polymerized Scotch-Weld 2216 B/A on <i>B. safensis</i> spore integrity.

<p>Only partially-embedded spores were counted (directly on the surface of Scotch-Weld 2216 B/A, treated by ultrasonication; surface location was confirmed by using Cy5 surface marker).</p

Surface embedded spores of <i>G. stearothermophilus</i> in cured Scotch-Weld 2216 B/A.

<p>(A) Scanning electron micrograph. Spores on the right side of the image appear sharply outlined and are apparently either surface-attached or partially embedded and protruding from the surface of Scotch-Weld 2216 B/A. Spores on the left side of the image appear more deeply embedded below the surface. (B) Overview of embedded spores at starting position of dual beam FIB/SEM measurement. The rectangle shows the area where the FIB ablation was performed to image the sample cross section. Spores partially embedded in the surface of cured Scotch-Weld 2216 B/A are visible. During sectioning of the samples with FIB, which removes layer after layer of 1 µm thickness each, vertical sections can be visualized by SEM to obtain a side view of the embedded spores in the adhesive (Fig. 1, C). (C) The outline of spores embedded in or near the surface of Scotch-Weld 2216 B/A can be seen along the cross section. Spores are partially or fully embedded (circles). Kaolin (filler material in Scotch-Weld 2216 B/A) inclusions are also visible (marked by arrows).</p

Mean molecular biocontamination of Solithane 113 determined by qPCR.

<p>Mean molecular biocontamination of Solithane 113 determined by qPCR.</p

Survival of <i>B. safensis</i> spores in uncured polymer precursors (gray bars) relative to the initial inoculum (10⁷ spores/mL, dilution in aqueous diluent), and growth of 10² cfu of <i>B. safensis</i> in the presence of uncured polymer precursors on nutrient agar (white bars) relative to the population of <i>B. safensis</i> grown without precursors.

<p>Survival of <i>B. safensis</i> spores in uncured polymer precursors (gray bars) relative to the initial inoculum (10⁷ spores/mL, dilution in aqueous diluent), and growth of 10² cfu of <i>B. safensis</i> in the presence of uncured polymer precursors on nutrient agar (white bars) relative to the population of <i>B. safensis</i> grown without precursors.</p

List of materials analyzed, their preparation, and the solvent most suitable for dilution of the uncured precursors.

1<p>mixed thoroughly for 5 min.</p>2<p>mixed thoroughly for 1–2 min.</p