Fig. 7

The six genes co-expression system and the influence on cell morphology, PHA production. a The co-expression of six genes in E. coli JM109 ∆minCD. The pathway presented in a was the order of functional proteins in the division process. FtsA and ZipA bind directly to FtsZ polymers at the division site, followed by the sequential addition of FtsK, FtsQ, FtsL, FtsW, FtsI and FtsN. b The cell growth CDW by E. coli JM109 ∆minCD containing plasmid pBBR-Pbad-ftsQLWN and ptk-mreB-ftsZ, the arabinose was added to the culture after 2 h of inoculation. The control was cultivated under the same condition. Error bars are s.d. (n = 3). c The cell dry weight and PHA contents by the recombinant strain. The strains were grown in the LB medium at 30 °C to an OD600 = 0.4–0.6, followed by induction with 0.2 % arabinose for 6 h, then addition of 20 g/L glucose. Error bars are s.d. (n = 3). The SEM results of strains E. coli JM109 (pBBR1-MCS1, ptk-blank,pBHR68) (d) and E. coli JM109 ∆minCD(pBBR-Pbad-ftsQLWN,ptk-mreB,pBHR68) (e), Scale bars,10 μm. The TEM of PHB accumulation in E. coli JM109 (pBBR1-MCS1, ptk-blank,pBHR68) (f) and E. coli JM109 ∆minCD (pBBR-Pbad-ftsQLWN,ptk-mreB,pBHR68) (g), Scale bars, 2 μm. (d–g) All the strains were grown in the LB medium at 30 °C to an OD600 = 0.4–0.6, followed by induction with 0.2 % arabinose for 6 h, then addition of 20 g/L glucose for another 40 h of cultivation