TRY GROWING YOUR OWN MOLDS IN A MOIST CHAMBER!!!
The material that supports the growth of a fungus is called its
substrate. A commercially prepared medium like
potato agar is one kind of substrate, but any organic material can be
The simplest method of growing molds is to put
a substrate like bread in a moist chamber. The substrate provides nutrients,
and the chamber maintains the high humidity that favors the growth of
fungi. Placing a slice of bread, fruit or vegetable, or a leaf in a
plastic sandwich bag is a simple way to use this method. The small
plastic bag must have a tie, a fold-over top or another way of sealing
it. Mold growth should be visible after 3 to 5 days. If you want to
try this experiment, follow the directions below.
You will need the following items:
- Substrate material
- Sandwich bags with a tie, fold top or "zip lock".
- A marker to label the bags.
- Damp, NOT WET, paper towels.
Making the moist chambers
- Label the bags with a number so you can tell them apart.
- Place a damp towel in each bag.
- Place a slice of bread or other substrate on top of the damp towel.
- Seal the bags.
- Record the substrate put in each bag.
- Place the bags in a warm area out of direct sunlight where they will not
- Check the bags each day. Fungal growth should be visable in 3 to 5 days.
Fungi are fuzzy or hairy and may be green, white, black, yellow, etc. Bacterial
colonies are shiny or slimy and may also be different colors.
- Record the number, color, and size of the fungal colonies. One very fast
growing fungus, the Galloping Grey Ghost (Rhizopus stolonifer), may
completely cover bread in just a couple of days.
Questions to help design experiments
- Are there differences in the numbers and kinds of fungi growing on
different kinds of bread?
- Does preservative in some bread affect the numbers and kinds of
- Are there differences in the numbers and kinds of fungi growing on bread
compared to carrots?
Last update: 16 Feb 99. © 1999, Robert Fogel, Ivins, UT 84738. Edited by Patricia Rogers.