Nav: Home

Bacterium makes complex loops

February 27, 2020

A scientific team from the Biosciences and Biotechnology Institute of Aix-Marseille in Saint-Paul lez Durance, in collaboration with researchers from the Max Planck Institute of Colloids and Interfaces in Potsdam and the University of Göttingen, determined the trajectory and swimming speed of the magnetotactic bacterium Magnetococcus marinus, known to move rapidly. The actual speed is 400-500 μm/s for a 1 μm bacterium, making it a swimming champion. More surprisingly, the trajectory is made up of complex spirals. The exceptional properties of this bacterium make possible to imagine its use as a micro-robot in the fields of biotechnology and the environment.

The magnetotactic bacterium Magnetococcus marinus lives in marine sediments. Its apparent swimming speed, which is very fast, was previously estimated at 100 μm/s. Spherical in shape, it has two packs of flagella on one of its hemispheres. The exact movement, supposedly helical in the presence of a magnetic field, with the head in front and the flagella at the back, however, remained hypothetical.

To answer this question and determine the real swimming speed of this bacterium, scientists from the Max Planck Institute of Colloids and Interfaces in Potsdam, the University of Göttingen and their colleagues from BIAM at CEA-Cadarache had to develop new experimental and numerical tools. The movement of these micro-swimmers was tracked by 3-dimensional microscopy and analysed by very high frequency black field imaging to decompose the movement of the flagella. This experimental work was complemented by original simulations to see which flagellum configurations could reproduce the movement observed experimentally.

The conclusion is astonishing. The flagella are arranged at 180° on either side of the head of the bacterium, with one bundle pulling and another growing, a configuration never observed before for bacteria or even for any known microorganism. The resulting movement describes double or even triple spirals! Magnetococcus marinus makes complex loops of sorts.

What about speed? The real speed is not the apparent speed, as the spirals considerably increase the travelled distance. The real speed is in the range of 400 to 500 μm/s for a bacteria measuring 1 μm. So it moves 500 times its own size, every second. This figure should be compared to the speed of movement of other known bacteria (40 to 50 μm/s), or to the swimming speed of our champions, of the order of 2 m/s, i.e. about one time its size per second for humans...

So Magnetococcus marinus is the queen of the podiums! Researchers are wondering about the origin of these performances and propose the hypothesis that this type of spiral swimming has an advantage in a sedimentary environment full of obstacles, which loops would allow to avoid. This particularity could be exploited in medical micro-robotics, to move in the blood of patients. It could also be used to sanitize areas polluted with oil or heavy metals, for example, which the bacteria could suck up and release in suitable spaces.
-end-
Original Publication

K. Bente, S. Mohammadinejad, et al.

High-speed motility originates from cooperatively pushing and pulling flagella bundles in bilophotrichous bacteria

eLife (2020)

https://elifesciences.org/articles/47551

Max-Planck-Gesellschaft

Related Bacteria Articles:

Bacteria might help other bacteria to tolerate antibiotics better
A new paper by the Dynamical Systems Biology lab at UPF shows that the response by bacteria to antibiotics may depend on other species of bacteria they live with, in such a way that some bacteria may make others more tolerant to antibiotics.
Two-faced bacteria
The gut microbiome, which is a collection of numerous beneficial bacteria species, is key to our overall well-being and good health.
Microcensus in bacteria
Bacillus subtilis can determine proportions of different groups within a mixed population.
Right beneath the skin we all have the same bacteria
In the dermis skin layer, the same bacteria are found across age and gender.
Bacteria must be 'stressed out' to divide
Bacterial cell division is controlled by both enzymatic activity and mechanical forces, which work together to control its timing and location, a new study from EPFL finds.
How bees live with bacteria
More than 90 percent of all bee species are not organized in colonies, but fight their way through life alone.
The bacteria building your baby
Australian researchers have laid to rest a longstanding controversy: is the womb sterile?
Hopping bacteria
Scientists have long known that key models of bacterial movement in real-world conditions are flawed.
Bacteria uses viral weapon against other bacteria
Bacterial cells use both a virus -- traditionally thought to be an enemy -- and a prehistoric viral protein to kill other bacteria that competes with it for food according to an international team of researchers who believe this has potential implications for future infectious disease treatment.
Drug diversity in bacteria
Bacteria produce a cocktail of various bioactive natural products in order to survive in hostile environments with competing (micro)organisms.
More Bacteria News and Bacteria Current Events

Trending Science News

Current Coronavirus (COVID-19) News

Top Science Podcasts

We have hand picked the top science podcasts of 2020.
Now Playing: TED Radio Hour

Climate Mindset
In the past few months, human beings have come together to fight a global threat. This hour, TED speakers explore how our response can be the catalyst to fight another global crisis: climate change. Guests include political strategist Tom Rivett-Carnac, diplomat Christiana Figueres, climate justice activist Xiye Bastida, and writer, illustrator, and artist Oliver Jeffers.
Now Playing: Science for the People

#562 Superbug to Bedside
By now we're all good and scared about antibiotic resistance, one of the many things coming to get us all. But there's good news, sort of. News antibiotics are coming out! How do they get tested? What does that kind of a trial look like and how does it happen? Host Bethany Brookeshire talks with Matt McCarthy, author of "Superbugs: The Race to Stop an Epidemic", about the ins and outs of testing a new antibiotic in the hospital.
Now Playing: Radiolab

Speedy Beet
There are few musical moments more well-worn than the first four notes of Beethoven's Fifth Symphony. But in this short, we find out that Beethoven might have made a last-ditch effort to keep his music from ever feeling familiar, to keep pushing his listeners to a kind of psychological limit. Big thanks to our Brooklyn Philharmonic musicians: Deborah Buck and Suzy Perelman on violin, Arash Amini on cello, and Ah Ling Neu on viola. And check out The First Four Notes, Matthew Guerrieri's book on Beethoven's Fifth. Support Radiolab today at Radiolab.org/donate.