[The intensification of the Voges-Proskauer-reaction by fumarate].

The influence of different substances and growth temperatures on the Voges-Proskauer-reaction of Vibrio spec. (HIM 627-1) was investigated by gas chromatographic analysis of acetoin produced and the Voges-Proskauer-reaction itself. The most efficacious conditions for a maximum production of acetoin and the result of the Voges-Proskauer-reaction, respectively, were cultivation of the bacteria in complex Voges-Proskauer-medium in the presence of 0.03 M glucose and 0.05 M fumarate at 37 degrees C. The examination of various so-called Voges-Proskauer positive bacterial strains showed that the production of acetoin and the Voges-Proskauer-reaction, respectively, was increased by cultivation of the bacteria in the presence of fumarate. Fumarate did not influence the reaction of the so-called Voges-Proskauer negative strains, so that false-positive reactions did not occur.