W hat does Christopher Columbus have in common with tiny
microorganisms?
Slide 4
Light Temperature Food And alarm substances or other chemical
compounds Scientists have known for a long time that bacteria can
orient themselves using:
Slide 5
Richard P. Blakemore in 1975, discovered the existence of
magnetotactic bacteria in a mud sample. These bacteria have
organelles called magnetosomes that contain magnetic
crystals.organelles magnetosomes
Slide 6
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. LIFE FORMS SHAPED LIKE TINY
FOOTBALLS
Slide 7
What is the structure of these extremely unusual nano crystals?
Figure 1: Diagram of a magnetotactic bacterium
Slide 8
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. The magnetosomes present in various types of bacteria
often have different shapes:
Slide 9
Figure 3: Diagram showing how magnetotactic bacteria use
magnetotaxis to swim to the OATZ in the Northern versus the
Southern Hemisphere on Earth
Slide 10
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. 30
s120 s
Slide 11
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.
Slide 12
Slide 13
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.
Slide 14
"Now, my own suspicion is"Now, my own suspicion is that 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
earth than are dreamed of, or can be dreamed of, in any philosophy.
J.B.S. Haldanethat 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
Slide 15
Slide 16
References: 1. Faivre, D. & Schler D. Magnetotactic
bacteria and magnetosomes. Chemistry Reviews 108, 48754898 (2008).
2. Gorby, Y. A., Beveridge T. J., & Blakemore R. P.
Characterization of the bacterial magnetosome membrane. Journal of
Bacteriology 170, 834841 (1988). 3. Thomas-Keprta K. L. et al.
Magnetofossils from ancient mars: a robust biosignature in the
martian meteorite ALH84001. Applied and Environmental Microbiology
68, 36633672 (2002).