Influence of pH on the growth characteristics of Neisseria gonorrhoeae in continuous culture.

A series of three continuous cultures of Neisseria gonorrhoeae was performed at pH values ranging from 6.4 to 7.2, with an average duration of 3 weeks. The maximal yield obtained was 1.12 mg/ml at a pH of 6.75 and a dilution rate of 0.26 per hr. Some morphological variations were observed at lower dilution rates, but complement-fixation titers remained stable for the duration of the cultures.