A Dominican Monk, Albert The Great, born in 1193, called Natural Baltic Amber Succinium and stated that it was the most effective of the leading medicines of the time. In order of effectiveness he listed them as Succinium, ocastoreum, mors, camphor, tartarus, and aurum. Amber tinctures were made from beer, wine and water. People found them effective against everything from stomach aches to rheumatism.

These results show that in S. cerevisiae as described increased succinic acid production about 3 times. Additional overexpression of mitochondrial fumarate reductase (FRDm1) from T. brucei further increased succinic acid production levels; overexpression of PCKa, MDH3, FUMR, FRDm1 resulted in production of 2.6 g/L succinic acid(cas:110-15-6), and overexpression of PCKm, MDH3, FUMR and FRDm1 resulted in production of 2.7 g/L succinic acid(cas:110-15-6). Overexpression of delta12NMDH2 in combination with PCKm, FUMR and FRDm1 resulted in production of 2.7 g/L succinic acid(cas:110-15-6), indicating that similar levels of succinic acid were produced using either truncated MDH2 or MDH3. Additional overexpression of glycosomal fumarate reductase (FRDg) from T. brucei resulted in an even higher increase in succinic acid(cas:110-15-6) production levels; overexpression of PCKa, MDH3, FUMR and FRDg resulted in production of 3.9 g/L succinic acid, whereas overexexpression of PCKm, MDH3, FUMR and FRDg resulted in slightly lower production of 3.6 g/L succinic acid.

An improved process for preparing ammonium salts from fumaric or succinic acid(cas:110-15-6), is described. The method consists of neutralizing the corresponding acid carbonate or ammonium bicarbonate at a molar stoichiometric or greater than the stoichiometric ratio of 4-5% in a saturated aqueous solution of the synthesized salt at a temperature not exceeding 40° C., followed by separation of the product and drying at a temperature not exceeding 70° C. After separation of the ammonium salts, the filtrate can be re-used. Isolation of the product is usually carried out by cooling the reaction mixture to a temperature of 15-18C°.