Mold needs three things to survive or grow: Water, Food and Warmth. Short of converting your basement into a walk in Freezer I would tackle the first item...moisture.
having lived in the Mid west as a child and young adult I remember the evils of high humidity. Get a dehumdifier or two and bring the moisture levels down. Mold and mildew are common in bathrooms because of the increases in humidity...the bath fan is great tool for keeping things under control ( run for 20 to 30 min after a shower) A second line of defense is the use of mold and mildew resistant paints.
You need to make sure there is not a constant source of moisture first . Then clean with a mold inhibiter , then paint and prime with kilz primer sealer and paint as normal. It worked for us. And we have an old farm with a walk out basement.