Effect of high concentrations of nicotinic acid and nicotinamide on growth of some streptococci and pneumococci

In a previous publication1 it was reported that in a simple chemically defined medium, growth of a number of the gram-negative enteric bacteria, together with a few other miscellaneous types, was markedly retarded or completely inhibited by 5000 or 10,000 /xg per ml of nicotinic acid or nicotinamide. The medium was composed of ammonium phosphate, glucose, salts, and in some cases small amounts of one or two additional vitamins or amino acids