Glutamic acid manufacture

Crystallization Method. Such methods as mechanical separation, preferential crystallisation, and substitution crystallisation procedures are included in this category. The preferential crystallisation method is the most popular. The general procedure is to inoculate a saturated solution of the racemic mixture with a seed of the desired enantiomer. Resolutions by this method have been reported for histidine (43), glutamic acid (44), DOPA (45), threonine (46), A/-acetyl phenylalanine (47), and others. In the case of glutamic acid, the method had been used for industrial manufacture (48). 

An estimation of the amount of amino acid production and the production methods are shown ia Table 11. About 340,000 t/yr of L-glutamic acid, principally as its monosodium salt, are manufactured ia the world, about 85% ia the Asian area. The demand for DL-methionine and L-lysiae as feed supplements varies considerably depending on such factors as the soybean harvest ia the United States and the anchovy catch ia Pern. Because of the actions of D-amiao acid oxidase and i.-amino acid transamiaase ia the animal body (156), the D-form of methionine is as equally nutritive as the L-form, so that DL-methionine which is iaexpensively produced by chemical synthesis is primarily used as a feed supplement. In the United States the methionine hydroxy analogue is partially used ia place of methionine. The consumption of L-lysiae has iacreased ia recent years. The world consumption tripled from 35,000 t ia 1982 to 100,000 t ia 1987 (214). Current world consumption of L-tryptophan and i.-threonine are several tens to hundreds of tons. The demand for L-phenylalanine as the raw material for the synthesis of aspartame has been increasing markedly. 

Japanese have also shown interest in poly-(L-glutamic acid) for the manufacture of silk-like fibres. 

Mention should also be made of glutamic acid and invert sugar which are used in foodstuffs and demand the use of hydrochloric acid-resistant material in manufacture, and of the essential flavouring oils which should preferably be stored and prepared in stainless steel and aluminium equipment. 

Classical examples of industrial biotechnology include the manufacture of ethanol, lactic acid, citric acid, and glutamic acid. The share of renewables in the feedstock of the chemical industry is expected to increase substantially in the years to come [2-4], A newcomer here is propane-1,3-diol (DuPont/Tate Lyle), with the start-up of industrial fermentation foreseen within one year. 

By market volume the most important flavour molecule is L-glutamic acid. In 2004, the worldwide annual MSG production was estimated to be amount 1,500,0001 [21]. The amino acid is extensively used as taste enhancer, frequently in conjunction with nucleotides, a flavour impression which is also referred to as umamf, a term derived from the Japanese meaning deliciousness or a savoury or palatable taste. MSG is manufactured by aerobic cultivation of Coryne-bacterium glutamicum on starch hydrolysates or molasses media in large-scale bioreactors (up to 500 m ). Production strains with modified metabolic flux profiles and highly permeable cell walls for an improved product secretion are... 

MSG sells for about 2/kg, and glutamic acid (99.5% pure) for about 4/kg. The major manufacturers of these are Ajinomoto, Asahi Foods, Kyowa Hakko, Takeda (Japan), Orsan (France), Biacor (Italy), Cheil Sugar, Mi-Won... 

Procedure Using 2-mL aliquots of both the Standard Solution and the Sample Solution, proceed according to the apparatus manufacturer s instmctions. From the chromatograms thus obtained, match the retention times produced by the Standard Solution with those produced by the Sample Solution, and identify the peak produced by glutamic acid. Record the area of the glutamic acid peak from the Sample Solution as A j, and that from the Standard Solution as As. 

De novo fermentation has long been the method of choice for the manufacture of many natural L-amino acids, such as glutamic acid and lysine, and hydroxy acids such as lactic and citric acids. More recently, de novo fermentation is displacing existing multistep chemical syntheses, for example in the manufacture of vitamin B2 (riboflavin) and vitamin C. Other recent successes of white... 

The fermentation uses glucose-containing organic feedstock it is aerobic and the L-glutamic acid is excreted by the cell into the surrounding liquid medium. The glutamic acid is separated from the fermentation broth by filtration the filtrate is concentrated and the acid is allowed to crystallize. MSG is manufactured on a large scale in many countries and is an additive in many food items. The worldwide production is estimated to be 800,0001. 

Monosodium glutamate (MSG) is a flavor enhancer. U.S. 2,877,160 (to Pfizer) and U.S. 2,978,384 (to Koichi Yamada) describe fermentation processes for glutamic acid. U.S. 5,907,059 (to Amylum Belgium A. E. Staley Manufacturing) describes recovery of the fermentation product and conversion to MSG. Estimate the cost of production via this route. 

Monosodium glutamate is the monosodium salt of the naturally occurring L-form of glutamic acid. It is commonly manufactured by fermentation of carbohydrate sources such as sugar beet molasses. In general, sugar beet products are used in Europe and the USA. Other carbohydrate sources such as sugar cane and tapioca are used in Asia. 

Efforts to develop organisms that overproduce L-phenylalanine have been vigorously pursued by the Nutrasweet Company, Ajinomoto, Kyowa Hakko Kogyo, and others. The focus has centered on bacterial strains that have previously demonstrated the ability to overproduce other amino acids. Such organisms include principally the coryneform bacteria, Brevibacterium flavum [1,2] and Corynebac-terium glutamicum [3,4] used in L-glutamic acid production. In addition, Escherichia coli has been extensively studied for L-phenylalanine manufacture due to... 

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