Figure 3

Influence of the physiological stage of 4HB addition on P4HB synthesis. E. coli JM109 (pKSSE5.3) were grown in a 1 L bioreactor at 32°C on modified E2 medium supplemented with 10 g L^-1 xylose, 4 g L ^-1 Na-4HB, 1 g L^-1 NZ-amines, 100 μg mL^-1 ampicillin and 0.015 g L^-1 thiamine. The black arrows represent the addition of the Na-4HB precursor. Panel A: addition of Na-4HB at different growth stages. I: Addition of Na-4HB at the beginning of the culture; II: Addition of Na-4HB at the end of the exponential growth phase; III: Combination of addition of Na-4HB at the beginning and at the end of exponential growth phase. Panel B: Time courses of P4HB content and concentration presented in log-scale. Panel C: P4HB productivity. The P4HB accumulation rate for the described conditions is obtained from three independent cultivations.