A novel strategy for succinate and polyhydroxybutyrate co-production in Escherichia coli

Based on the metabolic analysis, a succinate and polyhydroxybutyrate (PHB) co-production pathway was designed and engineered in Escherichia coli MG1655. Batch cultivation of the engineered E. coli revealed that it was able to accumulate both extracellular succinate and intracellular PHB simultaneously. PHB accumulation not only improved succinate production, but also reduced pyruvate and acetate secretion. With a consumption of 45 g l(-1) glucose, E. coli QZ1112 was shown to accumulate 24.6 g l(-1) succinate and 4.95 g l(-1) PHB in batch fermentation. The PHB content reached 41.3 wt.% of its cell dry weight, which suggested that the cell debris can be used as value added by-product.