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.
Highlights
Manned space missions conducted over the past 50 years have expanded our knowledge of the universe, and have led to the identification of a range of challenges that must be addressed as we move towards the phase of human space exploration
The biomass and mean thickness of the biofilms were determined from images obtained from confocal laser scanning microscopy (CLSM) with the aid of COMSTAT software [21]
The number of viable cells in P. aeruginosa biofilms formed in Modified artificial urine media (mAUM) during spaceflight increased three-fold compared to those formed in normal gravity (p,0.01) (Figure 1A)
Summary
Manned space missions conducted over the past 50 years have expanded our knowledge of the universe, and have led to the identification of a range of challenges that must be addressed as we move towards the phase of human space exploration. A key concern is how microgravity and other aspects of the spaceflight environment affect bacterial growth, physiology and virulence. Several in-flight studies have reported that the microgravity environment encountered during spaceflight can alter bacterial growth and physiology, including increased final cell density, antibiotic resistance, and virulence (reviewed by Horneck et al [1]). Spaceflight has been shown to have harmful effects on astronauts including decreased immune system function [2]. Recent in-flight studies using Drosophila and mouse models have shown that spaceflight can suppress the innate immune system [3,4]. The combined microgravitational effects of decreased immune function in space travelers and increased resistance and virulence in bacteria may be detrimental to the health of the crew during long-term space exploration
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
