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Bacteria use a compass to navigate

Bacteria use a compass to navigate . Presented by: Marwa Mahmoud. W hat does Christopher Columbus have in common with tiny microorganisms?. Scientists have known for a long time that bacteria can orient themselves using:. Light Temperature Food

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Bacteria use a compass to navigate

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  1. Bacteria use a compass to navigate

  2. Presented by: MarwaMahmoud

  3. W hat does Christopher Columbus have in common with tiny microorganisms?

  4. Scientists have known for a long time that bacteria can orient themselves using: • Light • Temperature • Food • And alarm substances or other chemical compounds

  5. Richard P. Blakemore in 1975, discovered the existence of magnetotacticbacteria in a mud sample. • These bacteria have organelles called magnetosomes that contain magnetic crystals.

  6. LIFE FORMS SHAPED LIKE TINY FOOTBALLS • Freshwater and marine habitats. • Anaerobes -too much oxygen can kill them. • Mud-water interface. • One micrometer (a thousandth of a millimeter) in size. • Spiral, rod or comma shaped • life forms; some even resemble • tiny footballs.

  7. What is the structure of these extremely unusual nano crystals? Figure 1: Diagram of a magnetotactic bacterium

  8. The magnetosomes present in various types of bacteria often have different shapes: Figure 2 : The electron microscopial images show structures in the shape of droplets (a), projectiles (b) and cubes (c, d). The magnetic particles are arranged in either one (a, b) or several (c, d) chains.

  9. Figure 3: Diagram showing how magnetotactic bacteria use magnetotaxis to swim to the OATZ in the Northern versus the Southern Hemisphere on Earth

  10. 30 s 120 s Figure 4: The microorganisms that are initially distributed uniformly and randomly, swim in a controlled manner to the northerly edge of the sample when a magnetic field is applied.

  11. Applications • Biotechnological application for medical diagnostics Magnetosome particles could be used in the detection of tumours (magnetic resonance tomography). • Help us to understand the origin of life • on Earth and elsewhere in the universe.

  12. Challenges • We still have not managed to grow bacteria in the laboratory in the required quantities. • The production of magnetite is particularly sensitive to subtle changes in the cultivation process. • And the greater the quantity, • the more complex the procedure.

  13. "Now, my own suspicion isthat the universe is not only queerer than we suppose,but queerer than we can suppose.I suspect that there are more things in heaven and earththan are dreamed of, or can be dreamed of, in any philosophy.” J.B.S. Haldane

  14. References: 1. Faivre, D. & Schüler D. Magnetotactic bacteria and magnetosomes. Chemistry Reviews108, 4875–4898 (2008). 2. Gorby, Y. A., Beveridge T. J., & Blakemore R. P. Characterization of the bacterial magnetosome membrane. Journal of Bacteriology170, 834–841 (1988). 3. Thomas-Keprta K. L. et al. Magnetofossils from ancient mars: a robust biosignature in the martian meteorite ALH84001. Applied and Environmental Microbiology68, 3663–3672 (2002).

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