Engineering a glycerol utilization pathway in Corynebacterium glutamicum for succinate production under O2 deprivation

Objective

To explore the glycerol utilization pathway in Corynebacterium glutamicum for succinate production under O₂ deprivation.

Result

Overexpression of a glycerol facilitator, glycerol dehydrogenase and dihydroxyacetone kinase from Escherichia coli K-12 in C. glutamicum led to recombinant strains NC-3G diverting glycerol utilization towards succinate production under O₂ deprivation. Under these conditions, strain NC-3G efficiently consumed glycerol and produced succinate without growth. The recombinant C. glutamicum utilizing glycerol as the sole carbon source showed higher intracellular NADH/NAD⁺ ratio compare with utilizing glucose. The mass conversion of succinate increased from 0.64 to 0.95. Using an anaerobic fed-batch fermentation process, the final strain produced 38.4 g succinate/l with an average yield of 1.02 g/g.

Conclusions

The metabolically-engineered strains showed an efficient succinate production using glycerol as sole carbon source under O₂ deprivation.