Study: Bacteria and electrons share behaviour
An unexpected shared pattern in the collective movement of bacteria and electrons has been discovered by scientists at Massachusetts Institute of Technology (MIT), USA, and the University of Cambridge, UK.
As bacteria stream through a microfluidic lattice, they synchronise and swim in patterns much like those of electrons orbiting around atomic nuclei in a magnetic material, the researchers say.
This discovery was made by tuning certain dimensions of the microfluidic lattice, which allowed the researchers to direct millions of microbes to align and swim in the same direction. This is similar to the way that electrons circulate in the same direction when they create a magnetic field.
With slight changes to the lattice, groups of bacteria flowed in opposite directions, resembling electrons in a nonmagnetic material.
The researchers also identified a mathematical model which applies to the motions of both bacteria and electrons. The model derives from a general lattice field theory, which is typically used to describe the quantum behaviour of electrons in magnetic and electronic materials. The researchers reduced this complex model to a much simpler one which predicts that a phase transition, or a change in flow direction, should occur with certain changes to a lattice’s dimensions – a transition that the team observed in its experiments with bacteria.
According to Jörn Dunkel, assistant professor of applied mathematics at MIT: “It’s very surprising that we see this universality. The really nice thing is you have a living system here that shows all these behaviours that people think are also going on in quantum systems.”
Moving forward, Dunkel says his next goal is to explore how collective motion of bacteria is controlled by the randomness of the medium.
The research was funded, in part, by an Advanced Investigator Grant from the European Research Council, the Engineering and Physical Sciences Research Council, an MIT Solomon Buchsbaum Fund Award, and an Alfred P Sloan Research Fellowship.
Hugo Wioland, Francis Woodhouse, and Raymond Goldstein, of Cambridge University, carried out the research alongside Dunkel. It has been published in the journal Nature Physics.
