[Action of isoniazid on the growth of saprophytic mycobacteria].
The effect of isoniazide on the ability to assimilate hydrophilic (sugars) and hydrophobic (hydrocarbon) substrates was studied with saprophytic mycobacteria. The minimal concentration of isoniazide inhibiting the growth of saprophytic mycobacteria in a medium containing hexadecane was 150 mcg/ml. If isoniazide was added at a concentration of 900 mcg/ml at the beginning of the logarithmic growth phase, the growth was sharply inhibited and assimilation of the hydrocarbon decelerated 4 times. The same concentration of isoniazide hardly affected the growth of the saprophytic mycobacteria in a medium containing a carbohydrate.