Molecular mechanism of magneto-aerotaxis in bacteria

• Applicant: Professor Dr. Dirk Schüler
• Subject Area: Metabolism, Biochemistry and Genetics of Microorganisms
• Term: from 2012 to 2018
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 228478880

• Final Report Year: 2017

Final Report Abstract

Magnetotactic bacteria are characterized by chains of intracellular ferromagnetic nanoparticles and their ability to sense the geomagnetic field, which is believed to facilitate directed motion, but is not well understood at the behavioural and molecular level. We found that cells of Magnetospirillum gryphiswaldense unexpectedly display swimming polarity that depends on aerotactic signal transduction through one of its four chemotaxis operons (cheOp1). Growth of cells in magnetic fields superimposed on oxygen gradients results in a gradual inherited bias of swimming runs with one of the cell poles leading, such that the resulting overall swimming direction of entire populations can be reversed by changes in oxygen concentration. Our findings clearly show for the first time that there is a direct molecular link between aerotactic sensing and the determination of magnetotactic polarity, through the sensory pathway CheOp1.

Publications

• (2016) Magnetic guidance of the magnetotactic bacterium Magnetospirillum gryphiswaldense. Soft matter 12 (15) 3631–3635
  Loehr, J., D. Pfeiffer, D. Schüler, and Th. M. Fischer
  
• 2014. Polarity of bacterial magnetotaxis is controlled by aerotaxis through a common sensory pathway. Nat. Comm. 5:5398
  Popp, F., J. Armitage, and D. Schüler
  
• 2015. An intracellular nanotrap re-directs proteins and organelles in live bacteria. mBio, 6(1):e02117-14
  Borg, S., F. Popp, J. Hofmann, H. Leonhardt, U. Rothbauer, and D. Schüler