E. coli spin symmetrical metal pucks via fluid dynamics
Get the Health newsletter
Daily health & science — research, biotech, public health, the studies worth knowing. Free.
- Palacci's team at ISTA, collaborating with UC San Diego's Tanumoy Dhar and David Saintillan, published in Nature Physics showing E. coli rotate symmetrical micro-disks placed in bacteria-filled active baths.
- Daniel Grober used a 3D nanoprinter to 3D-print the hockey-puck-shaped disks; they spun clockwise in the baths, disproving the team's earlier hypothesis that asymmetrical shapes were required for rotation.
- The driving mechanism is hydrodynamic, not mechanical contact: the counter-rotation of E. coli bodies and flagella twists surrounding fluid, generating torque on the disk without the bacteria ever touching its walls.
- Pucks with multiple compartments spun faster than simpler designs, and a single-compartment puck rotated as soon as one E. coli swam through, suggesting confinement amplifies the rotational force.
- The effect is cumulative and shape-agnostic, meaning it should occur whenever bacteria are confined in tight spaces — including biofilms linked to antibiotic resistance and soils where bacteria sustain ecosystems.
- Palacci said the effect has been overlooked until now and expressed hope the finding could inform medical therapeutics and sustainability efforts.
Why it matters: The finding reframes how confined bacteria interact with their surroundings: E. coli generate torque through fluid dynamics alone, meaning rotation is happening constantly in tight natural spaces like biofilms and soils. That has direct stakes for understanding antibiotic resistance (biofilms are a key defense) and bacterial roles in soil ecosystems.
Ask SkimNews
