S FLAVICIN: AN ANTIBACTERIAL SUBSTANCE PRODUCED BY AN ASPERGILLUS FLAVUS’

Since the discovery of penicillin by Fleming (1) in 1929 a number of investiga-tions have been carried out on antibacterial substances produced by micro-organisms. As a result of these investigations it has been shown during the past few years (2-7) that besides Fleming’s Penicillium notatum other fungi and bacteria are able to produce powerful bacteriostatic and bactericidal agents. Some of these substances such as gramicidin and tyrocidin (8) are quite toxic. On the other hand, penicillin (9) seems to have almost no toxic action. The search for relatively non-toxic substances among this group of extremely active bacterial inhibitors is of great interest for the development of new chemothera-peutic agents. While studying the production of penicillin we isolated a mold belonging to the Aspergillus flavws group which produced a powerful antibacterial substance. This mold appeared as a contaminant on one of our cultures of Penicillium notatum and our interest was aroused in it due to our finding that it was able to dissolve Staphylococcus aureus and Staphylococcus albus. On further study w