Fig. 4

Effect of β-alanine addition on P(3HB) production in E. coli transformants. The transformants of E. coli JM109/pSTV28 + pQE-Ma-phaABEC (open circles) and JM109/pSTV-Pp-coaA + pQE-Ma-phaABEC (open triangles) were cultivated in 30 mL of minimal medium containing various concentrations of β-alanine for 48 h at 37 °C. The methyl ester prepared from P(3HB) was analyzed using GC-FID. The panels A, B, C, and D are the same as Fig. 3. The significant difference between coaA – and + at each concentration of β-alanine was compared with an unpaired Student's t-test: *, p < 0.05; **, p < 0.01; ***, p < 0.001. The data are shown as the mean ± SD (n = 3)