Figure 1.
Spaceflight increases biofilm formation by P. aeruginosa.
Wild-type P. aeruginosa was cultured under normal gravity (black bars) and spaceflight (grey bars) conditions in mAUM or mAUMg containing 5 or 50 mM phosphate. (A) The number of surface-associated viable cells per cellulose ester membrane. (B) Biofilm biomass and (C) mean biofilm thickness were quantified by analysis of CLSM images. Error bars, SD; N = 3. *p≤0.05, **p≤0.01.
Table 1.
Spaceflight and motility affect biofilm formation and architecture.
Figure 2.
P.aeruginosa biofilms cultured during spaceflight display column-and-canopy structures.
Confocal laser scanning micrographs of 3-day-old biofilms formed by wild type, ΔmotABCD, and ΔpilB comparing normal gravity and spaceflight culture conditions. All strains were grown in mAUMg with 5 mM phosphate. No significant differences in structure or thickness were observed with mAUMg containing 5 or 50 mM phosphate. (A) Representative side-view images. (B) Representative 5.8 µm thick slices generated from partial z stacks. Maximum thickness is indicated in the upper right corner of the top slice for each condition.
Figure 3.
Increased oxygen availability minimizes gravitational effects on biofilm formation by P.aeruginosa.
Representative side view confocal laser scanning micrographs of 3-day-old biofilms formed by wild-type P. aeruginosa and ΔmotABCD grown in mAUMg with gas exchange (GE) inserts comparing normal gravity and spaceflight culture conditions.
Figure 4.
Illustration summarizing the influence of gravity, flow, and motility on P.aeruginosa biofilm architecture.