Microscopic pirates attack with mobile cannons and grappling hooks

Microscopic battles are constantly raging around us, on us and within us, and the microbial warriors use far more exciting weapons than we perhaps realize. Scientists have now observed a bacteria that attacks like a pirate ship, catching its prey with grappling hooks and firing “cannons” that blow it open.

The species in question is known as Aureispiraa common marine bacterium that can thrive in water or on surfaces. If there are enough nutrients in its environment, Aureispira will lead a peaceful life. But once the food runs out, the bug turns to the pirate life and hunts down other unsuspecting bacteria, using techniques that would make Jack Sparrow proud.

First it snakes its way toward its prey, then it fires tiny grappling hooks that wrap around the target’s flagella – these whip-like appendages are used by many bacteria for locomotion, so hooking onto these hooks prevents escape.

Next, Aureispira fires its cell cannons – structures called contractile injection systems that function like bolt guns, firing high-velocity projectiles. These penetrate the outer membrane of the prey cell and burst its innards Aureispira can then devour.

“The whole scene resembles a pirate attack on another ship,” said Martin Pilhofer, lead author of the study.

Aureispira It was already known to carry out such an attack, but for the new study, researchers took a closer look, using light microscopy and cryo-electron microscopy. These technologies helped study the function and structure of the weapons. The team also observed that the bacterium exhibits this behavior in the wild, but only does so when natural nutrients become scarce.

As for what we might do with this information, the team says at this point it’s mostly just basic research driven by their own curiosity. But a better understanding of these cellular weapons could eventually be used to eradicate infections or algal blooms or to deliver drugs to cells in the body.

For now, we just need to use the study to stimulate our imagination about the microscale sea battles taking place everywhere.

The research was published in the journal Science. Some of the fights can be seen in the video below.

Source: ETH Zurich