Penicillium colony Area of 。1928-Fleming inhibition of bacterial growth discovered penicillin, produced by Penicillium. 1940 Howard Florey and Ernst Chain performed first clinical trials of Normal penicillin. bacterial colony Figure 20.1 • 1928 – Fleming discovered penicillin, produced by Penicillium . • 1940 – Howard Florey and Ernst Chain performed first clinical trials of penicillin. Figure 20.1