The Production of Two Antibacterial Substances, Fumigacin and Clavacin

Publisher Website
Google Scholar
Abstract
Two spp. of Aspergillus were studied in greater detail: A. fumigatus, of which 16 strains were isolated from different soils, and A. clavatus, represented by 3 strains isolated from stable manure. In synthetic media, these 2 organisms produced active substances, that differed greatly in their chemical nature and in biological activity. Fumigacin is isolated from the medium by adsorption on norit, and subsequent elution with chloroform, after preliminary treatment of the norit with ether. Fumigacin is markedly different from the pigment fumigatin, isolated by Raistrick and associates, in its mode of formation, chem. properties and biol. activity. Clavacin can be extracted from the culture medium by direct treatment of the culture filtrate with ether and chloroform, or it can first be adsorbed on norit and then removed from the latter by means of these solvents. Clavacin is particularly active against gram-negative bacteria, the colon-aerogenes group being nearly as sensitive as staphylococci and spore-forming bacteria. Another important characteristic of this substance is its high bactericidal property. It is known that most antibiotic substances act upon bacteria primarily as a result of their bacteriostatic properties; they are rather weakly bactericidal. Clavacin appears to be distinct from these in this respect, possessing both high bacteriostatic and high bactericidal properties, 6 to 18-hour-old-cultures of various gram-negative and gram-positive bacteria being killed within 2-6 hrs. by dilution of 1:50,000 to 1:500,000 of the crude clavacin.