Dense cultures of Neisseria gonorrhoeae in liquid medium.

Cultivation of Neisseria gonorrhoeae was effected in a conical glass culture vessel surrounded by a constant-temperature water jacket, and with facilities for stirring, aeration, and pH measurement and control. With the use of an aerated peptone-based medium, containing polypropylene glycol to prevent foam build-up, the yields obtained over the pH range from 5.8 to 7.4 were determined. The greatest yield was obtained at pH 6.4 when the dry weight was 1.5 g/liter. At pH 7.2 to 7.6, lysis was extensive.