Citric acid synthesis was first indicated as a fungal product by Wehmer in 1893 by a strain of Penicillium glaucum on sugar- based medium. After a few years, he isolated and cultivated two types of fungal strains with the capability to accumulate citric acid, which was selected Citromyces (Penicillium). However, microbial production of citric acid did not become industrially important until World War I disrupted Italian citrus exports. The world production of this citric acid by fermentation is rapidly increasing.
In 1917 Pfizer hired James Currie, a food chemist, who had the daring idea of producing citric acid without using citrus. The production of citric acid is the oldest and most thoroughly studied filamentous fungal fermentation, dating back to 1917, when Currie optimized the conditions using a surface cultivation method.
The first citric acid fermentation was performed in surface cultures. In 1930, some units imbedded in England, in Soviet Union, and for the profitable production of citric acid in Germany.
The crystalline structure of anhydrous citric acid, obtain by cooling hot concentrated solution of the monohydrate form, was first discovered by Yuill and Bennet in 1934 by X-ray diffraction. In 1960 Nordman and co-workers further two molecules of acid are linked through hydrogen bond between two -COOH group of each monomer.
The central role of citric acid in the metabolism of all aerobic organisms was undisclosed by Krebs in the late 1930s.
Citric acid plays a central role in the biochemical cycle found by Kerbs in 1937. The production of citric acid lemon juice peaked in year 1915-1916 at 17,500 tonnes.
In 2011, Bichara and co-workers published the outcomes of the structural and vibrational theoretical study for the citric acid dimer.
Albert Szent-Györgyi at the University of Szeged (Hungary) and Hans Adolf Krebs at the University of Sheffield (UK); were the two key researchers awarded the Nobel Prize in Physiology or Medicine in 1937 and 1953, respectively for contribution to the discovery and establishment of the citric acid cycle.
History of citric acid
