Someone on the Food Network demonstrated a strategy for preventing growth
of mold on cheese, and it seems logical that it would work for bread, too.
Sprinkle a paper towel with a small amount of vinegar and fold the paper to
fit the container you use for storing the cheese (bread). Place a few lumps
of sugar around the object, then cover the container. The vinegar
supposedly will prevent mold from forming. If any spores are present,
they're supposed to be attracted to the sugar and leave the cheese (bread)
alone. I plan to try it for both cheese and bread.