[Bistability in the activity of glutamine synthetase in ammonium-limiting chemostat cultures of Escherichia coli ML 30].

The approximative estimation of the function micron([NH+4]) in cultures of E. coli ML 30 had shown that bistability of the ammonium concentration in ammonium limited continuous cultures could be possible (BERGTER et al. 1977). This phenomenon suggested a bistability in the regulation of ammonia assimilation. Therefore, the activity of one key enzyme of the two ammonia assimilation systems was measured. The distribution of the activity of glutamine synthetase in ammonia limited continuous cultures after different transition states confirmed this suggestion.