Both during the preparation for spaceflight experiments and to fully understand the results
after the experiment, scientists used spaceflight analogues, like the rotating wall vessel (RWV)
and the random position machine (RPM) to mimic spaceflight growth conditions in order to
gain insight into the potential behavior P. aeruginosa in microgravity (Nickerson 2004). For
Microbe, microarray analysis samples of P. aeruginosa grown in a RWV were compared to
samples grown in normal gravity controls (Crabbé 2010). The results revealed an alteration in a
regulatory role of the sigma factor AlgU, which consequently led to an increase in production of
the extracellular substance alginate. This change in gene regulation and increased production of
alginate resulted in an increase in heat and oxidative stress resistance. Perhaps most interesting
was the involvement of Hfq in response to culture in the RWV, consistent with Microbe
spaceflight findings in S. Typhimurium and P. aeruginosa.
The Microbe experiment had far reaching implications. It clarified the mechanisms behind the
observations of microbial spaceflight experiments over the past 40 years and initiated studies
to understand how these findings impact risk assessment to crew health. In addition, the
knowledge gained from spaceflight research has been the focus of commercial and academic
entities toward the discovery of novel therapeutic and vaccine approaches leading to the
implementation of new strategies for translation of this research into health benefits for the
general public (Sarker 2010).
PUBLICATION(S)
Crabbe A, Nielson-Preiss S, Woolley CM, et al. Spaceflight enhances cell aggregation and
random budding in Candida albicans. PLOS ONE. December 4, 2013;8:e80677. doi:
10.1371/journal.pone.0080677.
Crabbe A, Schurr MJ, Ott CM, et al. Transcriptional and proteomic responses of Pseudomonas
aeruginosa PAO1 to spaceflight conditions involve Hfq regulation and reveal a role for oxygen.
Applied and Environmental Microbiology. 2011;77(4):1221-1230. doi: 10.1128/AEM.01582-10.
Crabbe A, Pycke B, Van Houdt R, et al. Response of Pseudomonas aeruginosa to low shear
modeled microgravity involves AlgU regulation. Environmental Microbiology. 2010;12(6):1545-
64.
Sarker SF, Ott CM, Barrila J, Nickerson CA. Discovery of spaceflight-related virulence
mechanisms in Salmonella and other microbial pathogens: Novel approaches to commercial
vaccine development. Gravitational and Space Biology. 2010;23(2):75-78.
Nauman EA, Ott CM, Sander E, et al. A novel quantitative biosystem to model physiological
fluidsShear stress on cells. Applied and Environmental Microbiology. February 2007;73(3):699-
705.
Sittka A, Pfeiffer V, Tedin K, Vogel J. The RNA chaperone Hfq is essential for the virulence of
Salmonella typhimurium. Molecular Microbiology. 2007;63(1):193-217. doi: 10.1111/j.1365-
2958.2006.05489.x.