hindered the growth of bacteria. The shy and reticent researcher concluded
that there must be a substance in the nasal discharge that had inhibitory
powers, naming it lysozyme. For the first time in world history, a purely
organic substance had been characterized as having antibacterial
properties.
Lysozyme became a fascination for Fleming, albeit a research dead-end.
In time, researchers were able to show how lysozymes function to weaken
the cell walls of bacteria, but more important, the recognition of a
molecule that inhibited, or killed, microbes prepared Fleming’s mind for
his revolutionary observation in 1928.
As summer turned to fall in 1928, Alexander Fleming returned to
London from a holiday by the sea. When he arrived at his petite laboratory
at St. Mary’s Hospital (preserved today as a memorial to the man and his
momentous discovery that September 3), a jumbled stack of Petri dishes
was on a tabletop, including a dish that had fallen off its perch and lost its
lid. The story goes that he glanced at the Petri dish and quickly did a
double take—dozens of round spots of staphylococci carpeted the dish but
their spread was limited by a large island of white mold on one side of the
dish. Recognizing a pattern similar to what he had seen five years earlier,
the blotch of mold had a surrounding beltway, a demilitarized zone of
sorts, where there were no bacterial colonies and no fungus.
Fleming muttered softly to himself, “That’s odd.”
For thousands of years, humans had unwittingly harnessed mold to
make wine and beer and bacteria to make cheese. Fewer than one hundred
years before Fleming’s discovery, Louis Pasteur had solved the riddle of
fermentation, and less than half a century before, Koch had demonstrated
that bacteria were real. Fleming had already concluded five years earlier
that lysozymes from human fluids retained antibacterial properties, and
now, perched in his little lab above Praed Street, began conceptualizing
that the mold itself was making a substance that was deadly to the
staphylococcus.
The name of the mold? Penicillium. (Read that carefully. It doesn’t say
“Penicillin.”)
The Penicillium mold was likely a contaminate in the building or from
the air from an open window. There has been much conjecture about the
source of the mold—was it from a nearby lab, was its presence a hallmark
of sloppiness of research, did it taint the bacterial culture because
marcin
(Marcin)
#1