1. Magnetotactic Bacteria
Day 3

2. What is Magnetotactic Bacteria?
“Magneto-”: Magnetic
“-Taxis”: Behavioral response to a stimuli
First discovered by Richard Blakemore in 1975
Found worldwide in marine habitats

3. A Quick Review: What is Magnetism?
Some electrons spin one way and some spin another way.
Usually these electrons cancel each other out.
Extra unpaired electrons can go either way and become… MAGNETIZED!

4. A Quick Review: What are Magnetic Fields?
Magnetic Fields – Guides which tell us which direction compasses will point
Field lines start from the north to the south

5. What is the Earth’s Geomagnetic Field?
The Earth is like a giant magnet with a geographic AND magnetic north pole and a south pole.
Geographic North Pole = Magnetic South Pole
Geographic South Pole = Magnetic North Pole

6. What is the Earth’s Geomagnetic Field?

7. What is the Earth’s Geomagnetic Field?
The Earth creates its magnetic field from electric currents in its liquid iron-nickel core
Magnetic Fields are created when electrical charges move.
Magnetic Fields are not always the same. They change over time.

8. MOVIE:

9. Why are Magnetotactic Bacteria Magnetic?
Contains Magnetosomes – Organelles that contain magnetite (Fe3O4) or greigite (Fe3S4)
Imagine magnetic crystals
Generally magnetosomes per bacteria

10. Why are Magnetotactic Bacteria so Interesting?
The magnetosomes act like a compass needle in the bacteria.
The bacteria are slightly anaerobic (doesn’t like oxygen very much)
The magnetosomes (and Earth’s magnetic field) helps these bacterial reach optimal (the best) oxygen conditions.

11. Why are Magnetotactic Bacteria so Interesting?
Magnetotactic Bacteria orient themselves differently depending on which hemisphere they live in.
Northern Hemisphere – The Earth’s magnetic field lines point slightly down (into the center of the Earth)

12. Magnetotactic Bacteria in Action!
MOVIE: /

13. Applications for Magnetotactic Bacteria
Magnetic separation of materials
MRI
Hyperthermia
Microchips
Carrier of antibiotics, drugs, etc.
Robotic technology
Eradication of heavy metals (Pollutant absorbers and/or biosensors)
Cancer