Pfizer Ltd

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Penicillin Production What does the penicillin
fungus need to grow?
? Pfizer Ltd
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This is Penicillium the fungus that produces
penicillin, the first of the antibiotic wonder
drugs. Antibiotics kill bacteria without harming
humans. Penicillin has saved many, many millions
of lives since it was discovered and treated
millions of minor infections as well.
? Alan Silverside
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As a fungus, Penicillium cannot photosynthesise.
A solution containing corn liquor (containing
sugar), nitrate fertilisers and yeast extract is
added to the fungus in a giant tank or fermenter.
This provides all of the required nutrients, and
fermentation begins.
? Pfizer Ltd
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Temperature, oxygen concentration and pH are
controlled in the fermenter. Large paddles swirl
the medium around to keep everything well mixed.
Over the next 140 hours the fungus will grow and
start to produce penicillin.
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After about 140 hours roughly 30 of the mixture
will be drained off and fresh nutrient added. The
material that has been drained off is passed to a
separator. Why wait until 140 hours before this
is done?
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The separator acts a bit like a spin-dryer a
vacuum draws mixture onto a rotating drum. The
drum is porous so the dissolved penicillin passes
through into the centre while the fungal
filaments are stuck on the outside. These
filaments are removed by a blade as the drum
rotates.
? Pfizer Ltd
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The filtered liquid with the dissolved penicillin
is treated with potassium salts. This
precipitates the penicillin out of solution. This
precipitate can then be collected by filtering
and the powder produced can be as high as 99.5
pure penicillin.
NOAA
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Penicillin and the other antibiotics which have
been discovered are some of the most useful
medicines we have. Doctors all over the world
prescribe them to save patients from the effects
of bacterial disease.