FURTHER STUDIES ON THE LETHAL EFFECT OF LONG-CHAIN FATTY ACIDS ON MYCOBACTERIA

Abstract
Mycobactericidal activity of long-chain fatty acids was confirmed by in vitro exposure of [Mycobacterium bovis] BCG. The killing effect was accompanied by inhibition of the membrane-bound acid phosphatase activity. Such active fatty acids were those having a stronger hemolytic activity (e.g., C12:0, C14:0, C18:1, C18:2). Heat-killed BCG cells or their cell walls adsorbed the toxic fatty acids, the fatty acid-insensitive Escherichia coli cells did not. The mycobactericidal action of long-chain fatty acids is possibly due to their detergent-like action on the cytoplasmic membrane, and the determinant factor for the fatty acid-sensitivity of bacteria could be the property of the cell wall by which fatty acids are adsorbed so that the active site is brought into contact with the inner membrane. [These studies have relevance to the possible association of tissue fatty acids with tuberculosis development.].