science · 15 July 1941 · 83 years ago
In 1941, development work began on the mold cultures Howard Florey and Norman Heatley had brought with them from England to the Northern Regional Research Lab of the U.S. Dept of Agriculture in Peoria, Illinois. They wanted to produce sufficient quantities for treatment of the many wartime military casualties. The potency of the sample provided was preserved by a freeze-drying process devised by Ernst Chain. Heatley remained to get the mold culture started, while Florey left on 17 Jul to enlist drug companies. In the original process, mold was grown only on the surface of the medium in shallow pans. Instead, deep culture fermentation (similar to beer brewing) would be developed using tanks of corn steep liquor to provide a large volume for submerged growth. This greatly multiplied the yield.
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