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Bread Mold

SteveZiegenfuss reserc19 at ecity.net
Sun Mar 10 00:21:01 EST 1996

Mendocino Middle School Lab wrote:
> Hi,
>  My name is Lucy Haughwout, I¹m in 8th grade at the Mendocino Middle
> School. Our school is only 6th, 7th and 8th grade. Mendocino is a small
> town about 150 miles north of San Francisco.
>  I¹m writing you to try to get some information on my project. The topic I
> choose was mold, the type of mold I choose was bread molds. My
> Investigative  Question is:  How does bread mold spread? The reason why I
> choose this topic is because I was interested in how bread molds, in 6th
> grade we did an experiment on how bread molds, but we didn¹t really get
> into it and it wasn¹t very detailed and I didn¹t really learn much, so I
> wanted to an project on mold but this time more detailed.
>  We really don¹t have any good resources, we only have our library at the
> school which is very small and we are lacking books. In our area there is
> no big university, we only have a little collage which is even smaller
> then our library. I don¹t really know that much about mold, I do know that
> where we live on the coast there is a lot of mold because it is so damp. I
> also know that mold grows on food, like bread when it gets old. I know
> that bread mold usually looks green and and white little dots. I¹m pretty
> sure that there are different kinds of mold.
> These are a couple specific questions that I have,
> * What ingredients keep bread from molding of might cause faster mold?
> * What is the mold¹s life cycle?
> Even though we don¹t have good resources in books, we do have a full
> access to the inter net. So if you know of any web sites or other
> locations, we would be greatly appreciated.
>    Please write back to: search at mcn.org
> Here at the MMS we are putting together a list of previously written
> letters by subject matter, and I would by happy to add their
> correspondence to the list, if you give us the approval. They should tell
> on whether or not they wish to include their name and/or return e-mail
> address with the letters address with the letters so that other students
> who are interested on the topic in the future might get in touch with them
> or at least know who wrote the letter.
>    If they would like to see previously written letters, they are at the
> Electronic Dialogue Archive (EDA) being compiled at
> http://www.mcn.org/ed/earch
> Thank you,
> Lucy Haughowout
> --
> This message sent from the Mendocino Middle School Lab
> Please write postmaster at mail.mms.mendocino.k12.ca.us if
> it appears there has been misuse of this service

Hi Lucy,
	Ny name is Steve and I'm a research microbiologist.  I happen to 
work with molds that inhabit and grow in feeds and grains.  One of the 
subjects I study in my work is molds that spoil bread made from wheat and 
tortillas made from corn.
	You are correct in your guess that there are many molds which 
spoil bread.  The color of the mold can be one indication of the mold 
you've got growing, but is only one characteristic of the mold.  For 
scientific purposes you would need to use a 10X microscope or dissecting 
scope to see the fine detail of the mold in order to determine which 
specific mold you are looking at.
	One mold which commonly grows on my bread and tortillas in the 
lab is called Penicillium.  This is the genus from which penicillin, the 
antibiotic, was first isolated.  Some of the Penicillium molds are green, 
others grey, and even white.  The reason you can't eat moldy bread when 
you are sick and get an antibiotic is that only very specific Penicillium 
molds make penicillin when they grow.  Others make poisonous by-products 
when they grow.  Under a microscope this mold looks like fine hairs 
(hyphae) with paint brushes attached.  The paint brushes are the colorful 
part and are the spore production parts.  Spores are like the mold 
version of seeds.
	Another common mold on my samples is called Aspergillus.  
Aspergillus can look very much like Penicillium, but when you get it 
under a microscope they look very different.  Again the color can be 
green, yellow, black, even different shades of any of these colors.  
Under a microscope this mold looks line fine hairs (hyphae) with large 
baloons filled with spores attached.
	Other common bread molds could be Rhizopus, Monascus, Fusarium, 
and a whole host of others.
	The life cycle of a bread mold is really very simple.  It starts 
out as a wind blown spore landing on the bread.  Given sufficient 
moisture it will sprout and grow hyphae.  The hyphae are the hair-like 
things seeming to spread out over the bread.  The function as roots 
kinda.  After enough hyphae are produced to collect food and water, the 
mold starts to produce fruiting structures, sometimes called "conidia", 
where the paint brush like structures occur and spores are produced.
	Does this sound a little like a plant's life cycle?  It should.  
Molds are really very simple plants.
	There are many things you can do to prevent mold growth.  The 
baking at 400 degrees kills molds so the bread starts out mold free and 
sterile.  But there are mold spores virtually everywhere except maybe in 
hospital surgery rooms where many special and expensive steps are taken 
to maintain sterility.  You can also add chemicals to the food as long as 
they are safe to eat.  A common chemical used to preserve bread is called 
"propionic acid."  Another acid used to kill molds is called "acetic 
acid."  Acetic acid is the acid in vinegar.  Vinegar is really just 95 
parts water mixed with 5 parts acetic acid.  Both chemicals are safe to 
eat in very small amounts and prevent molds from destroying our bread 
before we can get it eaten.  Convenient, huh?!
	I hope this isn't too technical for you.  If it was not technical 
enough (I don't know how smart you are, maybe you're a whiz at science!) 
just let me know and I'll get technical as all get out for you.
	My son is 15 and he tells me I tend to talk down to him, but then 
I'm his Dad and you know how that can be.
	Good luck on your science project on molds.
	My email address is reserc19 at ecity.net and I check my email every 
day or two, sometimes three.  

See ya in the mold zone!


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