Chapter 1
Magnetite Biomineralization in Bacteria
Jens Baumgartner and Damien Faivre
Contents
1.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
1.2 Magnetotactic Bacteria . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
1.2.1 Ecology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
1.2.2 Diversity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
1.2.3 Genetics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
1.2.4 Cell Biology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
1.3 Magnetosomes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
1.3.1 Magnetite Biomineralization Pathway . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . . .. . . . . 9
1.3.2 Why Are Magnetosomes an Extraordinary Material? . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
1.4 Applications of Magnetosomes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
1.5 Conclusion and Outlook . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
Abstract Magnetotactic bacteria are able to biomineralize magnetic crystals in
intracellular organelles, so-called “magnetosomes.” These particles exhibit speciesand strain-specific size and morphology. They are of great interest for biomimetic
nanotechnological and biotechnological research due to their fine-tuned magnetic
properties and because they challenge our understanding of the classical principles
of crystallization. Magnetotactic bacteria use these highly optimized particles,
which form chains within the bacterial cells, as a magnetic field actuator, enabling
them to navigate. In this chapter, we discuss the current biological and chemical
knowledge of magnetite biomineralization in these bacteria. We highlight the
extraordinary properties of magnetosomes and some resulting potential
applications.
D. Faivre (*)
Department of Biomaterials, Max Planck Institute of Colloids and Interfaces, Wissenschaftspark
Golm, Potsdam 14424, Germany
e-mail: damien.faivre@mpikg.mpg.de
W.E.G. M€ uller (ed.), Molecular Biomineralization, Progress in Molecular
and Subcellular Biology 52, DOI 10.1007/978-3-642-21230-7_1,
# Springer-Verlag Berlin Heidelberg 2011
3
Magnetite Biomineralization in Bacteria
Jens Baumgartner and Damien Faivre
Contents
1.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
1.2 Magnetotactic Bacteria . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
1.2.1 Ecology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
1.2.2 Diversity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
1.2.3 Genetics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
1.2.4 Cell Biology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
1.3 Magnetosomes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
1.3.1 Magnetite Biomineralization Pathway . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . . .. . . . . 9
1.3.2 Why Are Magnetosomes an Extraordinary Material? . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
1.4 Applications of Magnetosomes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
1.5 Conclusion and Outlook . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
Abstract Magnetotactic bacteria are able to biomineralize magnetic crystals in
intracellular organelles, so-called “magnetosomes.” These particles exhibit speciesand strain-specific size and morphology. They are of great interest for biomimetic
nanotechnological and biotechnological research due to their fine-tuned magnetic
properties and because they challenge our understanding of the classical principles
of crystallization. Magnetotactic bacteria use these highly optimized particles,
which form chains within the bacterial cells, as a magnetic field actuator, enabling
them to navigate. In this chapter, we discuss the current biological and chemical
knowledge of magnetite biomineralization in these bacteria. We highlight the
extraordinary properties of magnetosomes and some resulting potential
applications.
D. Faivre (*)
Department of Biomaterials, Max Planck Institute of Colloids and Interfaces, Wissenschaftspark
Golm, Potsdam 14424, Germany
e-mail: damien.faivre@mpikg.mpg.de
W.E.G. M€ uller (ed.), Molecular Biomineralization, Progress in Molecular
and Subcellular Biology 52, DOI 10.1007/978-3-642-21230-7_1,
# Springer-Verlag Berlin Heidelberg 2011
3