|MadSci Network: Microbiology|
Being a microbiologist myself and trying to stay informed in this field, I must say that I find little to no information about this topic. The main reason I would suspect that magnets and magnestism would have little effect on bacterial growth is due to the nature of magnetic energy. Being that it is non-ionizing and or relatively weak strength, (relative to other types of energy) it wouldn't have the capacity to adversely affect DNA or other genetic material within the bacterial cell. Also, because there is very little ferric metal content (i.e. iron) in the walls and cytoplasm of bacterial structures to be found in most isolates from food, they too would remain unaffected. However, this is not to say that this experiment would be worthless.
Decreases in temperature generally slow metabolic functions in microoorganisms (MO) (i.e. bacteria, yeasts, molds, etc.) If treating MO's with cold and then subjecting them to magnetic energy would affect them, I cannot say. Another resource I would direct you to is the Americian Society for Microbiology (www.asm.org) which would have some if any info. on this subject.
Admin note: Magnetic fields have been shown to affect particular species of bacteria such as Magnetospirillum, which are found in certain sediments. However, I too know of no specific effects on anything you'd likely grow out of a regrigerator or "fuzzy food." A search of MEDLINE turned up no hits regarding organisms to be found in food. However, you could try searching it for magnetite magnetospirillum. Hope this helps..
-L. Bry, MadSci Admin
Try the links in the MadSci Library for more information on Microbiology.