Spaceflight Promotes Biofilm Formation by Pseudomonas aeruginosa
Wooseong Kim, Farah K. Tengra, Zachary Young, Jasmine Shong, Nicholas Marchand, Hon Kit Chan, Ravindra C. Pangule, Macarena Parra, Jonathan S. Dordick, Joel L. Plawsky, Cynthia H. Collins
Abstract
Understanding the effects of spaceflight on microbial communities is crucial for the success of long-term, manned space missions. Surface-associated bacterial communities, known as biofilms, were abundant on the Mir space station and continue to be a challenge on the International Space Station. The health and safety hazards linked to the development of biofilms are of particular concern due to the suppression of immune function observed during spaceflight. While planktonic cultures of microbes have indicated that spaceflight can lead to increases in growth and virulence, the effects of spaceflight on biofilm development and physiology remain unclear. To address this issue, Pseudomonas aeruginosa was cultured during two Space Shuttle Atlantis missions: STS-132 and STS-135, and the biofilms formed during spaceflight were characterized. Spaceflight was observed to increase the number of viable cells, biofilm biomass, and thickness relative to normal gravity controls. Moreover, the biofilms formed during spaceflight exhibited a column-and-canopy structure that has not been observed on Earth. The increase in the amount of biofilms and the formation of the novel architecture during spaceflight were observed to be independent of carbon source and phosphate concentrations in the media. However, flagella-driven motility was shown to be essential for the formation of this biofilm architecture during spaceflight. These findings represent the first evidence that spaceflight affects community-level behaviors of bacteria and highlight the importance of understanding how both harmful and beneficial human-microbe interactions may be altered during spaceflight.
Citation: Kim W, Tengra FK, Young Z, Shong J, Marchand N, et al. (2013) Spaceflight Promotes Biofilm Formation by Pseudomonas aeruginosa. PLoS ONE 8(4): e62437. doi:10.1371/journal.pone.0062437
Editor: Christophe Beloin, Institut Pasteur, URA CNRS 2172, France
Received: December 11, 2012; Accepted: March 20, 2013; Published: April 29, 2013
Copyright: ? 2013 Kim et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Funding: This work was supported by NASA Grant NNX09AI70G to CHC. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.
Competing interests: The authors have declared that no competing interests exist.
