Rotting Fruit and Antibiotics
Name: Cynthia W.
Date: November 2003
When fruit rots what kind of antibiotic can it produce? When fruit rots does it
produce a mold? Would a mold and an antibiotic be the same thing?
The fruit gives a variety of molds a home on which to grow and extract nutrients. Some of
these molds produce chemicals we call antibiotics that inhibit bacterial growth. Penicillium
is a mold that can grow on fruit and will produce chemicals that inhibit bacterial growth.
There are a number of molds that produce other chemicals ( streptomycin, tetracycline,
erythromycin) that we have isolated analyzed and produce artificially for "antibiotics"
most inhibit bacterial growth less inhibit mold growth. So far, we have the least success
with antibiotics against viruses.
Fruit rots because of a few things. First, the seeds are inside the fruit and there are
hormones that fruit produces that cause the fruit to break down so the seeds can be released
and a new generation can start. Also, fruit generally has a lower pH, ie. it is more acidic
than other foods. Most bacteria are inhibited by the low pH of some fruits. But mold can
grow in lower pH, therefore fruit is more often spoiled by mold than bacteria. Many molds
can try to breakdown one kind of fruit, so this causes competition between the molds. They
produce substances to repel each other and antibiotics are those substances. We take
advantage of the fact that these are produced by molds and bacteria and have figured out
ways to extract these antibiotics from them.
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Update: June 2012