The Production of Histamine in Bacterial Cultures.

In a previous paper (Eggerth, Littwin, and Deutsch, 1939) a simple and convenient method for the quantitative determination of histamine in bacterial cultures has been described. By this method, the cultures are made alkaline with sodium carbonate, then extracted in a special apparatus with a mixture of chloroform and amyl alcohol, the histamine passing into a layer of dilute sulfuric acid. Ammonia, volatile mines, and amyl alcohol are removed from this extract by boiling at pH 9.2. The histamine is determined calorimetrically by the method of Koessler and Hanke (1919a). The presence of histamine is then confirmed qualitatively by forming the di-picrate. In the present investigation, a series of organisms has been studied to determine which of them are capable of producing histamine, and what factors influence histamine production. A number of culture media were employed, as the composition of the medium profoundly affects the amount of histamine produced. A detailed report will be made of the following seven only. Histidine is an essential ingredient for all of them, for, with the exception of Clostridium welchii, none of the organisms studied were able to form histamine unless free histidine was present.' The first five media were adjusted to pH 7.6 and autoclaved; then enough sterile concentrated glucose solution was added to