Figure 1.

Influence of various factors on growth and P4HB accumulation. E. coli JM109 (pKSSE5.3) was grown in 1 L bioreactors in modified E2 medium. The modified E2 medium containing 10 g L⁻¹ xylose, 4 g L⁻¹ Na-4HB, 1 g L⁻¹ NZ-amines, and 1 mL L⁻¹ trace elements was used as standard medium. Culture A: standard medium; Culture B: two times more xylose was added to the standard medium, leading to 20 g L⁻¹ xylose; Culture C: five times more nitrogen source NaNH₄HPO₄ · 4H₂O was added to the standard medium, leading to a final NaNH₄HPO₄ · 4H₂O concentration of 17.5 g L⁻¹; Culture D: NZ-amine amount was increased by 5 fold, leading to 5 g L⁻¹; Culture E: three times more trace elements were added, leading to 3 mL L⁻¹; Culture F: three times more magnesium was added, leading to 3 mM of MgSO₄ · 7H₂O. The data are the average numbers of duplicates.