Absorption of Bacteriostatic Quantities of Fatty Acid from Media by Large Inocula of Tubercle Bacilli

Abstract

In cultivating tubercle bacilli it has been observed that addition of Tween 80 to the medium increased rapidity of growth and dispersion when a large inoculum was used, but little growth was obtained with small inocula unless serum albumin was added to the medium. Filtrates of a medium inoculated with large amts. of the tubercle bacilli supported growth from small inocula. Oleic acid was found to be the important inhibiting factor. Improvement in growth properties of a medium filtrate was found to be due to absorption of oleic acid by tubercle bacilli. Added serum albumin acted as a protective agent against the bacteriostatic action of oleic acid. There was no evidence that growth promoting factors were produced by growing tubercle bacilli. Tween-albumin media are not recommended for isolation of tubercle bacilli in diagnostic laboratory procedures.