Magnetotactic Bacteria Day 3 What is Magnetotactic Bacteria

Magnetotactic Bacteria Day 3

What is Magnetotactic Bacteria? “Magneto-”: Magnetic “-Taxis”: Behavioral response to a stimuli First discovered by Richard Blakemore in 1975 Found worldwide in marine http: //senr. osu. edu/Organisms_Living_on_Earth. html habitats

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! http: //www. rug. nl/zernike/research/groups/phynd/research/spinp olarizedtransport

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 http: //www. askamathematician. com/? p=4129

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 http: //adventure. howstuffworks. com/outdooractivities/hiking/compass 1. htm

What is the Earth’s Geomagnetic Field? http: //hyperphysics. phy-astr. gsu. edu/hbase/magnetic/magearth. html

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. http: //news. nationalgeographic. com/news/bigphotos/76158139. html

MOVIE: http: //geomag. org/info/Declination/magnetic_lines. avi

Why are Magnetotactic Bacteria Magnetic? Contains Magnetosomes – Organelles that contain magnetite (Fe 3 O 4) or greigite (Fe 3 S 4) Imagine magnetic crystals Generally 15 -20 magnetosomes per bacteria http: //www. ornl. gov/info/news/pulse/magbac_htm. jpg

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.

Why are Magnetotactic Bacteria so Interesting? Magnetotactic Bacteria orient themselves differently depending on which hemisphere they live in. http: //en. wikipedia. org/wiki/File: Hemisferio_Norte. png Northern Hemisphere – The Earth’s magnetic field lines point slightly down (into the center of the Earth) http: //visual. merriamwebster. com/earth/geography/cartography/hemispheres. php

Magnetotactic Bacteria in Action! MOVIE: /www. youtube. com/watch? v=WR 7 j 67 TABz. E

Applications for Magnetotactic Bacteria Magnetic separation of materials MRI Hyperthermia Eradication of heavy metals (Pollutant absorbers and/or biosensors) Cancer Microchips Carrier of antibiotics, drugs, etc. Robotic technology http: //sciencespot. net/Pages/kdzgen. html