S3: Fermentation of Glycerol for the Production of Succinic Acid by a Genetically Engineered E. coli.

            Succinic acid is currently derived from the petrochemical industry. It is useful as a monomer for plastic polymers and for the production of other chemicals.  Myriant Corporation has developed a fermentation process for producing succinate from glucose, using a genetically engineered strain of E. coli.  Glycerol is a major volume byproduct from the triglyceride transesterification process of the biodiesel industry.  With the growth of the biodiesel industry, it is estimated that 40 million gallons of glycerol were produced in 2010, an increase that has caused the price of crude glycerol to fall to as little as $0.05/lb.  As such, glycerol has become attractive as an inexpensive fermentation feedstock.

Starting with Myriant’s glucose utilizing strain of E. coli, genetic engineering techniques and metabolic evolution have developed a new strain that is capable of producing succinate from glycerol.  Since glycerol is a more reduced compound than glucose, a higher theoretical yield is possible and modifications to the fermentation process were necessary to reach titers, specific rates of production and yields comparable to those from glucose-fed fermentations.  The advantages of a glycerol based production of succinic acid will be presented.