  A study of the induced effect of different types of weak magnetic field
exposure on bacterial growth is performed, comparing the relative changes after
removal from the magnetic fields. This investigation is relevant to understand
the effect of magnetic field exposure on human beings due to electronic
devices. For this purpose, we use four species of common bacteria in reference
to human health and safety including Escherichia coli, Staphylococcus aureus,
Staphylococcus epidermidis, and Pseudomonas aeruginosa. The choice of these
four bacteria also allows us to check for effects which rely upon the
Gram-staining properties or shapes of bacterial species. These species were
initially exposed to static, non-homogeneous and alternating weak magnetic
fields, and then they were grown in incubators in the same environment at 37
{\deg}C simultaneously. Comparative measurements of optical density are then
used to track the sustained impact on bacterial growth in the experimental
samples. Bacteria was first grown in different weak magnetic fields on a plain
glass surface both in liquid and solid media. Magnetic field treated bacteria
were then transferred into similar test tubes to grow in an incubator
concurrently. Bacterial cultures in liquid nutrient broth on plain glass
proliferated faster in most species. Different magnetic fields affect the
growth pattern of bacteria differently, depending on the bacterial strain. The
weak magnetic field seems to decelerate the growth rate, even after the
magnetic field is removed. With application of this study, we can potentially
investigate the effect of weak field exposures on Eukaryotic cells and gene
dynamics.
