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Fig. 6 | Biotechnology for Biofuels and Bioproducts

Fig. 6

From: Systems metabolic engineering of Escherichia coli for hyper-production of 5‑aminolevulinic acid

Fig. 6

Fed-batch fermentation of strain ALA14 (A) and ALA26 (B) in 5-L bioreactors. Plasmid pZPW76 represents pTrc99A overexpressing hemAC75A/R365K, coaA, ppc, eamA and grxA. Plasmid pZCA136 represents pZCA9P overexpressing synthetic sRNAs targeting hemB, sucC and aceA. The chromosomal coaA copy was deleted in strain ALA26. Cultivation was performed in 5-L bioreactors using fermentation medium. IPTG (0.1 mM), aTc (100 ng/mL) and glycine (4 g/L) were added when OD600nm reached approximately 20 to induce gene expression and 5-ALA biosynthesis. Glucose and glycine were continuously fed into the bioreactor during the fermentation. The pH was controlled at 6.5 initially and switched to 6.0 at 14 h. The dissolved oxygen and cultivation temperature were maintained at 30% and 37 ℃ initially and switched to 10% and 30 ℃ at 18 h, respectively.

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