The first successful production of glutamic acid by fermentation

Soon after the war in 1946, Benzaburo Kato, President of KYOWA HAKKO KOGYO Co., Ltd., directed his employees to develop a technique to mass produce protein. Eight years later in 1956, they succeeded in producing monosodium glutamate by fermentation.

In 1946 Kato thought that lack of protein made the Japanese physique poorer when compared with those of Americans and Europeans. So he challenged his employees to develop the manufacturing of protein. Shukuro Kinoshita, who had just joined the company, went to work on creating a method of producing amino acids, which consist of protein, as it was more costly to produce just protein. To begin, Kinoshita paid attention to glutamic acid, which was already on the market.

Kikunae Ikeda succeeded in extracting glutamic acid from kombu (sea tangle) for the first time in the world. Ajinomoto Co., Inc., had already produced glutamic acid by hydrolyzing and extracting the protein of wheat and soy beans, but the amount of acid contained in protein was very little and costly to produce, driving up the price. Although Ajinomoto reviewed the method of chemical synthesis, it wasn’t put to practical uses.   

Kinoshita and others began to examine a fermentation method. This fermentation technique involved fermenting glucidic materials such as dextrin and molasses to produce amino acids. Some advantages of this method are that the materials didn’t cost alot and didn’t generate unnecessary by-products, unlike chemical synthesis. 

First of all, Kinoshita and team began looking for a glutamic acid strain. Shigezo Udaka found the strain (No.534 strain, Corynebacterium glutamicum) in soil that was mixed with animal dung at Ueno Zoo in Taito Ward, Tokyo. 
 
Next, they began to study the actual method of manufacturing. They could multiply the bacteria but could not generate glutamic acid just by culturing. However, in the course of their examinations, they discovered that the cell membranes of this strain received damage, and glutamic acid was secreted outside the cell when the level of biotin vitamin got insufficient. At that time, it was thought that microbes would not secrete amino acids, which were necessary for life preservation. This discovery overturned the theory.

Due to this find, it became possible to consistently generate glutamic acid. By fermenting microbes, KYOWA HAKKO KOGYO Co., Ltd. succeeded in 1956 to generate monosodium glutamates for the first time in the world. With this manufacturing method, glutamic acid, which had been expensive to make, came to be mass- produced inexpensively.   

Today, the production of glutamic acid via fermentation is done in all parts of the world. Annual production is reaching one million tons. Moreover, other amino acids are being produced by fermentation, and mainly in Japan.