(180b) Gravitational Effects On Biofilm Formation by Pseudomonas Aeruginosa

There is an urgent need to understand the effects of microgravity on the growth, cellular physiology, and cell-cell interactions in microbial biofilms. This information can then be used to curtail harmful activities of microbial consortia thriving as biofilms on the International Space Station and is essential for the long-term success of human space exploration. Bacterial biofilms were abundant on the MIR space station and were responsible for increasing corrosion and blocking a water purification system. Health and safety hazards linked to the development of biofilms are also of great concern because of the decreased in immune function observed in space travelers. We are using microarrays, laser scanning confocal microscopy, image analysis and the measurement of viable cell counts to develop a systems-level model of how gravity alters biofilm formation with the goal of developing new strategies to reduce their impact on the operation of spacecrafts and the health of their crew. We are focusing on Pseudomonas aeruginosa because it forms biofilms both inside and outside of the human body, can switch between benign and pathogenic interactions with humans, and may be relevant to crew health during extended missions. We are studying how gene expression and the three-dimensional structures of biofilms formed by these microbes differ in microgravity compared to normal gravity using both simulated microgravity and spaceflight experiments. We will present our recent results comparing biofilm formation on membranes in normal gravity, simulated microgravity and in spaceflight experiments.