Amino acids annual production

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... 

Today aspartame is used in more than 6,000 food products. Aspartame is 160 times as sweet as sucrose based on mass equivalents. Approximately 16,000 tons are consumed annually on a global basis, with approximately 8,000 tons used in the United States and 2,500 tons in Europe. In the body aspartame is metabolized into its three components aspartic acid, phenylalanine, and methanol (Figure 11.1). Aspartic acid is a nonessential amino acid and phenylalanine is an essential amino acid. The condition called phenylketonuria (PKU) is a genetic disorder that occurs when a person lacks the enzyme phenylalanine hydroxylase and cannot process phenylalanine. This results in high phenylalanine blood levels that are metabolized into products one of these is phenylpyruvate, which contains a ketone group and... 

Amino acid World annual production, tons Present mode of manufacture Characteristics... 

Very approximate annual worldwide production of amino acids, their current method of preparation (not exclusive), and general characteristics are given in Table 2. 

Hirose, Y., K. Sano, and H. Shibai Amino Acids, in Annual Reports oil Fermentation Processes, Academic Press, New York, NY, Vol. 2, (1978), pp. 155-189. Hochester. R.M. and R.W. Watson J. Am. Chem. Soc., 75, 3284-3285 (1953). Hohmann, N. and C.M. Rendleman Emerging Technologies in Ethanol Production, Agriculture Information Bulletin Number 663. 

Microbial amino acids are mostly produced in Japan 6). The annual production of amino acids in Japan had reached a level of 300 million dollars in 197747). Microbial amino acids can be produced directly from intermediates or by enzymatic methods. A variety of substrates are used for microbial growth. These include molasses (especially beet), hydrolyzate, glucose, xylose, acetic acid, methanol, ethanol, benzoic acid, and n-paraflin. Investigations are being made in the search for inexpensive and easily available carbon sources 48). 

Furuta S, Rousseau RW, Teja AS. Production of fine particles by rapid expansion of amino acid solutions at high temperatures and pressures. American Institute of Chemical Engineers, Annual Meeting, Miami, 1992 706-712. 

In the presence of the immobilized enzyme, the reaction can be carried out at a substrate concentration of up to 2 M, as has been demonstrated by Kyowa Hakko. In addition, an excellent conversion of >99% ee was obtained, accompanied by impressive enantioselectivities of >99.9% ee [32], Immobilized whole cells from Escherichia coli have been used by Tanabe Seiyaku for this reaction [34], It is worth noting that this reaction represents not only the first application of immobilized whole cells in industrial a-amino acid production, but also proved to be economically superior to fermentation methods (Fig. 14). A high yield of >95% has been obtained for L-aspartic acid, l-27, and the annual capacity is several hundred tons. 

A further industrially important lyase for the production of L-amino acids is the tyrosine phenol lyase [39]. This biocatalyst is used by Ajinomoto in the production of the pharmaceutically important L-3,4-dihydroxyphenylalanine (L-dopa), 32, which is applied in the treatment of Parkinson s disease. The reaction concept is based on a one-pot three-component synthesis starting from catechol, 30, pyruvic acid, 31, and ammonia in the presence of suspended whole cells (strain Erwinia herbicola) containing the tyrosine phenol lyase biocatalyst (Fig. 16). A key feature of this process is the high volumetric productivity of 110 g/L of the desired L-dopa product. Notably, this reaction runs with an annual capacity of 250 tons. 

The economic analysis of MBR processes is often a complex task, because it depends on many variables like the extent of reaction, number and configuration of the separation steps, etc. An interesting study was reported by Weuster-Botz et al [6.17] for the synthesis of L-isoleucine. Isoleucine is an amino acid, which is used in the preparation of infusion solutions in parenteral nutrition therapies its annual production is about 200 tons per year. Weuster-Botz et al [6.17] carried out an economic analysis for the production of... 

The theory and experiment of direct crystallization of enantiomers is quite well understood at present [10]. There are a number of variables which affect the resolution by direct crystallization in practice. Several technological schemes based on this principle are realized on the commercial scale. These are, for example, the Merck process used for the production of antihypertensive drug methyldopa [11], a process developed by Harman and Reimer for (-)-menthol, which is separated as an ester [12], the process patented by Industria Chimica Profarmaco for the resolution of naproxen enantiomers as the ethylamine salt [13], the production of L-glutamic acid by the Japanese company Ajinomoto on a scale in excess of 10000 tons annually as early as the 1960s [14], etc. In general, it seems that spontaneous crystallization is a very useful technique for the enantioseparation of the naturally occurring a-amino acids. All of them may be resolved either directly or as derivatives [10]. 

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