Nicotinic Acid as an Essential Growth-Substance for Dysentery Bacilli. ∗

Abstract

Recent evidence has shown that nicotinic acid is a compound of considerable biologic importance. Current interest in this compound can be attributed primarily to the work of Warburg, 1 Euler 2 and their associates, which demonstrated that the amide of nicotinic acid is a constituent of the coenzyme from horse blood and the cozymase of yeast.

To those interested in the nutritive requirements of microörganisms this work has been of considerable significance as it supplied a clue to the chemical identity of one of the essential substances, or “growth-factors,” needed for development of certain of the more exacting bacteria. In studies of Staphylococcus aureus Knight 3 demonstrated that a combination of nicotinic acid and vitamin B₁ (thiamin chloride) was effective in replacing a concentrate prepared from yeast. Neither substance would suffice in the absence of the other, but when both were supplied the staphylococcus developed in a culture-medium containing only known compounds. For growth of the diphtheria bacillus Mueller 4 found that nicotinic acid could replace one of several fractions obtained from liver. A combination of nicotinic acid, beta-alanine and, for some strains of the organism, pimelic acid was effective in promoting growth in the absence of tissue extract preparations. 5 Nicotinic acid without beta-alanine was relatively ineffective. 5

The work reported here deals with the growth-promoting effect of nicotinic acid upon dysentery bacilli. It is of interest for two reasons: first, through the use of nicotinic acid it is possible to cultivate dysentery bacilli in a solution of known chemical compounds and second, nicotinic acid alone is strikingly effective without the addition of any other “accessory” factor.