Culture device and methods for enumerating mold colonies

A thin-film culture device, comprising:

• a water-resistant first substrate;
• a water-resistant second substrate;
• a growth region disposed between the first and second substrates,
• wherein the growth region comprises:
• (a) an effective amount of calcium-chelating compound,
• (b) a nutrient medium capable of supporting growth of a mold microorganism,
• (c) a dry coating comprising ethylenediamine tetraacetic acid, and
• (d) a dry, cold-water-soluble gelling agent;
• wherein, when the growth region is hydrated with a predetermined volume of aqueous liquid and inoculated with a colony-forming unit of a mold species, the effective amount of calcium-chelating compound is capable of reducing a rate of lateral enlargement of the colony-forming unit growing in the culture device relative to the rate of lateral enlargement of a colony of the same mold species growing in an otherwise identical culture device that does not contain the effective amount disposed in the growth region;
• wherein reducing the rate of lateral enlargement of the colony-forming unit does not substantially delay detection of the colony.