Present addresses: Center for Infectious Diseases and Vaccinology, The Biodesign Institute, Arizona State University, 1001 S. McAllister Avenue, Tempe, AZ 85287, USA;
Response of Pseudomonas aeruginosa PAO1 to low shear modelled microgravity involves AlgU regulation
Article first published online: 5 MAR 2010
© 2010 Society for Applied Microbiology and Blackwell Publishing Ltd
Special Issue: Pseudomonas. Editors: Professors Burkhard Tummler, Victor de Lorenzo, Alain Filloux and Joyce Loper
Volume 12, Issue 6, pages 1545–1564, June 2010
How to Cite
Crabbé, A., Pycke, B., Van Houdt, R., Monsieurs, P., Nickerson, C., Leys, N. and Cornelis, P. (2010), Response of Pseudomonas aeruginosa PAO1 to low shear modelled microgravity involves AlgU regulation. Environmental Microbiology, 12: 1545–1564. doi: 10.1111/j.1462-2920.2010.02184.x
- Issue published online: 3 JUN 2010
- Article first published online: 5 MAR 2010
- Received 14 July, 2009; accepted 7 January, 2010.
As a ubiquitous environmental organism that is occasionally part of the human flora, Pseudomonas aeruginosa could pose a health hazard for the immunocompromised astronauts during long-term missions. Therefore, insights into the behaviour of P. aeruginosa under spaceflight conditions were gained using two spaceflight-analogue culture systems: the rotating wall vessel (RWV) and the random position machine (RPM). Microarray analysis of P. aeruginosa PAO1 grown in the low shear modelled microgravity (LSMMG) environment of the RWV, compared with the normal gravity control (NG), revealed an apparent regulatory role for the alternative sigma factor AlgU (RpoE-like). Accordingly, P. aeruginosa cultured in LSMMG exhibited increased alginate production and upregulation of AlgU-controlled transcripts, including those encoding stress-related proteins. The LSMMG increased heat and oxidative stress resistance and caused a decrease in the oxygen transfer rate of the culture. This study also showed the involvement of the RNA-binding protein Hfq in the LSMMG response, consistent with its previously identified role in the Salmonella LSMMG and spaceflight response. The global transcriptional response of P. aeruginosa grown in the RPM was highly similar to that in NG. Fluid mixing was assessed in both systems and is believed to be a pivotal factor contributing to transcriptional differences between RWV- and RPM-grown P. aeruginosa. This study represents the first step towards the identification of virulence mechanisms of P. aeruginosa activated in response to spaceflight-analogue conditions, and could direct future research regarding the risk assessment and prevention of Pseudomonas infections during spaceflight and in immunocompromised patients.