Effect of Tween 80 on the Growth of Tubercle Bacilli in Aerated Cultures.

Lyon, Richard H. (Veterans Administration Hospital, Minneapolis, Minn.), Herman C. Lichstein, and Wendell H. Hall. Effect of Tween 80 on the growth of tubercle bacilli in aerated cultures. J. Bacteriol. 86:280-284. 1963.-The effect of Tween 80 (polyoxyethylene sorbitan monooleate), glucose, and glycerol on aerated and stationary growth of Mycobacterium tuberculosis strain H(37)Ra was examined in Dubos liquid medium. Previous studies established that aeration (rotation) of liquid cultures of M. tuberculosis strains H(37)Ra and H(37)Rv caused an inhibition of growth in a medium containing glucose as a source of carbohydrate. The present studies show that Tween 80 exerts a toxic effect on the growth of tubercle bacilli in aerated cultures when glucose is present in the medium as the sole source of carbohydrate, but not when glycerol is included. The role of hydrolytic products of Tween 80, viz. oleic acid and the polyoxyethylene derivative of sorbitol, is discussed. The hypothesis is submitted that glycerol protects against the growth suppression by aeration because it reduces the concentration of free fatty acids in the medium to subinhibitory levels.