THE USE OF GLUCOSE INORGANIC SALTS MEDIA IN THE CLASSIFICATION OF THE COLI-AEROGENES BACTERIA. I. THE METHYL RED AND VOGES-PROSKAUER REACTIONS

SUMMARY: A chemically defined glucose ammonium phosphate medium gave methy red and Voges-Proskauer reactions which were superior to those in glucose peptone phosphate. Optimum condition for both tests require a starting pH of 6·8 and incubation for 3 days at 30°. The medium gave a negative correlation between the two reactions with 34 out of 35 strains that were positive to both tests in the peptone medium. The addition of glutamic acid helped to eliminate doubtful positive M. R. reactions but seemed to suppress acetylmethylcarbinol production by weakly V.-P. positive strains.