Studies in the biochemistry of micro-organisms

Abstract

IN a recent paper, Fleming [1929] showed that a mould which appeared as an air contaminant in laboratory bacterial cultures, and which resembled Penicillium rubrum Grasberger-Stoll, produced when grown on nutrient broth a very powerful antibacterial substance. Filtrates of the broth cultures were named "penicillin" and it was found that the active substance affected different bacteria in different degrees. The action was very marked on the pyogenic cocci and the diphtheria group of bacilli, whilst the coli-typhoid and the influenza bacillus groups were quite insensitive to it. Staphylococci, Streptococcus pyogenes and the pneumococcus were completely inhibited in a 1 in 800 dilution of the filtrate, which did not affect the growth of H. influenzae (Pfeiffer's bacillus), and a method was described for the isolation of H. influenzae by incorporating penicillin in a suitable solid medium.