Low-shear modeled microgravity: a global environmental regulatory signal affecting bacterial gene expression, physiology, and pathogenesis

• Published in: Journal of Microbiological Methods 2003-07, Vol.54 (1), p.1-11
• Main Authors: Nickerson, Cheryl A, Ott, C.Mark, Wilson, James W, Ramamurthy, Rajee, LeBlanc, Carly L, Höner zu Bentrup, Kerstin, Hammond, Timothy, Pierson, Duane L
• Format: Article
• Language: English
• Subjects: Bacteria; Bacteria - growth & development; Bacteria - pathogenicity; Bacterial Infections - microbiology; Bacterial Infections - physiopathology; Bacterial Proteins - genetics; Bacterial Proteins - metabolism; Biological and medical sciences; Bioreactor; Bioreactors; Cells, Cultured; Fundamental and applied biological sciences. Psychology; Gene expression; Gene Expression Profiling; Gene Expression Regulation, Bacterial; Humans; Life Sciences (General); Low shear; Microbiology; Modeled microgravity; Models, Biological; Optimized suspension culture; Pathogenesis; Physiology; Rotating wall vessel; Space life sciences; Stress, Mechanical; Virulence; Weightlessness Simulation
• ISSN: 0167-7012; 1872-8359
• DOI: 10.1016/S0167-7012(03)00018-6

Bacteria inhabit an impressive variety of ecological niches and must adapt constantly to changing environmental conditions. While numerous environmental signals have been examined for their effect on bacteria, the effects of mechanical forces such as shear stress and gravity have only been investigated to a limited extent. However, several important studies have demonstrated a key role for the environmental signals of low shear and/or microgravity in the regulation of bacterial gene expression, physiology, and pathogenesis [Chem. Rec. 1 (2001) 333; Appl. Microbiol. Biotechnol. 54 (2000) 33; Appl. Environ. Microbiol. 63 (1997) 4090; J. Ind. Microbiol. 18 (1997) 22; Curr. Microbiol. 34(4) (1997) 199; Appl. Microbiol. Biotechnol. 56(3–4) (2001) 384; Infect Immun. 68(6) (2000) 3147; Cell 109(7) (2002) 913; Appl. Environ. Microbiol. 68(11) (2002) 5408; Proc. Natl. Acad. Sci. U. S. A. 99(21) (2002) 13807]. The response of bacteria to these environmental signals, which are similar to those encountered during prokaryotic life cycles, may provide insight into bacterial adaptations to physiologically relevant conditions. This review focuses on the current and potential future research trends aimed at understanding the effect of the mechanical forces of low shear and microgravity analogues on different bacterial parameters. In addition, this review also discusses the use of microgravity technology to generate physiologically relevant human tissue models for research in bacterial pathogenesis.