AUG 04, 2019 4:29 PM PDT

How a Magnetic Bacterium Creates a Compass Needle

WRITTEN BY: Carmen Leitch

There are organisms that can use the magnetic field of the earth to navigate, including animals like honey bees and migratory birds, and some bacteria. Scientists have now learned more about how a strain type of bacteria, Magnetospirillum gryphiswaldense, use magentotaxis - their sense of the Earth’s magnetic field, for movement. The bacteria carry crystals of magnetite called magnetosomes, which can form a straight chain that functions as a sort of biological compass needle. The findings, which illustrate the role of a protein called MamY in the process, have been reported in Nature Microbiology.

The magnetosomes form a chain inside the bacteria's cell shows the electron cryotomography (ECT). / Credit: Helmholtz-Zentrum Berlin für Materialien und Energie

The spiral-shaped bacterium has around fifty magnetosomes inside it, which are anchored to a thread-like filament. They can thus clump together, or line up like a needle along the filament. The bacterium can then use the structure to swim along with the orientation of the planet’s magnetic field, and quickly reach the habitat they like - water body sediments.

In this work, the reseaarchers determined that a protein helps the bacteria form a straight line even though the bacterium is spiral-shaped. Using cryo-electron tomography and super-resolution microscopy, they found that the MamY protein orchestrates the lineup of magnetosomes, and optimally arranges the chain so it aligns the swimming movement of the microbe with the magnetic field - parallel to the cell’s longitudinal axis.

When these microbes lack MamY proteins, their magnetosomes cannot form a linear chain. The resulting compass needle structure is bent, and creates a wobble as the microbes swim. When these bacteria don’t have a filament that anchors the magnetosomes, no chains form at all and the magnetosomes just sit in a clump.

"All these observations confirm the conclusion:  MamY is the key protein that arranges the magnetosome chain in the cell in such a way that the function of a compass needle is perfectly fulfilled. The protein enables the bacteria to navigate optimally," noted the lead study author Dr. Frank Müller, a scientist in the Department of Microbiology at the University of Bayreuth.

Learn more about magnetic bacteria, and how they may benefit us, from the videos.

A JoVe publication (a peer-reviewed video journal) that describes how to collect and purify these bacteria can be found here.

Sources:  University of Bayreuth, Nature Microbiology

About the Author
  • Experienced research scientist and technical expert with authorships on over 30 peer-reviewed publications, traveler to over 70 countries, published photographer and internationally-exhibited painter, volunteer trained in disaster-response, CPR and DV counseling.
You May Also Like
MAY 13, 2021
Immunology
Salmonella Vaccine Uses "Molecular Telephones" to Talk to the Immune System
MAY 13, 2021
Salmonella Vaccine Uses "Molecular Telephones" to Talk to the Immune System
Salmonella infections are a massive problem—Over 95 million people are affected by this foodborne illness every ye ...
JUN 17, 2021
Immunology
How T Cells Sense Dangerous Invaders
JUN 17, 2021
How T Cells Sense Dangerous Invaders
T cells form a major part of our immune defenses, protecting us against the constant barrage of potentially pathogenic p ...
JUN 21, 2021
Coronavirus
COVID-19 Gives Dangerous Fungal Infections an Opening
JUN 21, 2021
COVID-19 Gives Dangerous Fungal Infections an Opening
In Brazil, clinicians have noted a rise in C. auris infections. Researchers believe that exhausted healthcare workers, o ...
JUN 21, 2021
Microbiology
In a Blow to Enzyme Latch Theory, Soil Microbes Break Down Polyphenols
JUN 21, 2021
In a Blow to Enzyme Latch Theory, Soil Microbes Break Down Polyphenols
Microbes have many connections to humans. Gut microbes have a major influence on our health. For example, when we eat fr ...
JUL 11, 2021
Microbiology
COVID-19 Delta Variant Seems to Grow Faster & Be More Contagious
JUL 11, 2021
COVID-19 Delta Variant Seems to Grow Faster & Be More Contagious
In October 2020, what's now called the Delta variant of SARS-CoV-2 was first detected. It's now the most prevalent strai ...
JUL 19, 2021
Cell & Molecular Biology
ATP & GTP Are Common in Biology - But What About CTP?
JUL 19, 2021
ATP & GTP Are Common in Biology - But What About CTP?
Adenosine triphosphate (ATP) is a molecule that provides crucial energy to activate a wide array of biological processes ...
Loading Comments...