Fig. 2
From: Metabolic pathway engineering using the central signal processor PII
NAGK specific activity in extracts of Synechocystis sp. PCC 6803 (wild-type) and the engineered strain BW86 incubated with nitrate (NO3 −), ammonium (NH4 +), or no nitrogen source (–N) until the late exponential phase (OD750 of about 0.8). For nitrogen starvation (–N), cells were incubated in nitrate-supplemented BG–11 medium to an OD750 of 0.5 and were then transferred to BG-11 medium without a nitrogen source and incubated for 2 days to an OD750 of 0.8