# Magnetic field platform for experiments on well-mixed and spatially structured microbial populations

## TL;DR

This paper introduces a 3D-printed device to study how magnetic fields affect microbial populations, finding that they slow the expansion of yeast mats in two dimensions but not in three.

## Contribution

The paper introduces an open-source, 3D-printed magnetic field exposure device for controlled microbial experiments.

## Key findings

- Static magnetic fields slow the 2D expansion of yeast mats on semi-solid media.
- Magnetic fields do not affect the growth of planktonic yeast cells in liquid media.
- The device is validated using simulations and experiments on Saccharomyces cerevisiae.

## Abstract

Magnetic fields have been shown to affect sensing, migration, and navigation in living organisms. However, the effects of magnetic fields on microorganisms largely remain to be elucidated. We develop an open-source, 3D-printed magnetic field exposure device to perform experiments on well-mixed and spatially structured microbial populations. This device is designed in AutoCAD, modeled in COMSOL, and validated using a Gaussmeter and experiments on the budding yeast Saccharomyces cerevisiae. We find that static magnetic field exposure slows the spatially structured expansion of yeast mats that expand in two dimensions, but not yeast mats that expand in three dimensions, across the surface of semi-solid yeast extract-peptone-dextrose agar media. We also find that magnetic fields do not affect the growth of planktonic yeast cells in well-mixed liquid yeast extract-peptone-dextrose media. This study provides an adaptable device for performing controlled magnetic field experiments on microbes and advances our understanding of the effects of magnetic fields on fungi.