CONTINUOUS-CULTURE STUDIES ON THE SYNTHESIS OF CAPSULAR POLYSACCHARIDE BY KLEBSIELLA-PNEUMONIAE K1

The synthesis of capsular polysaccharide by Klebsiella pneumoniae K1 w as investigated in a minimal salts medium by continuous culture. The o rganism produced larger amounts of polysaccharide under nitrogen-limit ed conditions than under carbon-limited conditions. The synthesis of p olysaccharide was dependent not only on the availability of excess car bon, but also on growth rate. The rate of polysaccharide synthesis was greatest at low dilutions, low temperature (30 degrees C) and at neut ral pH. Prolonged growth in nitrogen-limited culture resulted in the d evelopment of non-mucoid variants, possibly due to a selective growth advantage over mucoid cells. The non-mucoid isolate was more susceptib le to some bacteriophages, possibly due to the reduction or absence of capsular polysaccharide.