Scientists have isolated a biochemical reaction responsible for the effect of a magnetic field on bacteria.

They demonstrated that a weak magnetic field can affect production of a certain molecule found in a photosynthetic bacterium.

The team used a mutant strain of the bacterium Rhodobacter sphaeroides called R-26 that lacks a protective chemical known as a carotenoid that normally soaks up damaging radicals.

They found that a magnetic field of 20 millitesla, just 400 times the Earth’s magnetic field, was enough to cut singlet oxygen production by up to 50%, protecting the photosynthetic molecules against singlet oxygen damage. This suggests that the R-26 bacteria should grow better in a magnetic field.