Methionine manufacture

Recent estimates of the atmospheric loading rate of acrolein from sources in the United States were not located. Anderson (1983) estimated the total loading rate of acrolein in 1978 to be 91,450 pounds from facilities involved in its production and use as a chemical intermediate. Loading rates from various industrial sources were as follows acrylic acid manufacturers, 15,175 pounds refined acrolein and glycerin manufacturers, 55,660 pounds methionine manufacturers, 18,150 pounds and miscellaneous intermediate uses, 2420 pounds. These loading rates were based on a total production volume of 350 million pounds for acrolein in 1978, with 87% of this volume consumed in the production of acrylic acid and its derivatives. 

Because of the simplicity of swiae and poultry feeds, most feed manufacturers add vitamins (qv) and trace minerals to ensure an adequate supply of essential nutrients. Amino acids (qv) such as methionine [7005-18-7] lysiae [56-87-17, threonine [36676-50-3] and tryptophan [6912-86-3], produced by chemical synthesis or by fermentation (qv), are used to fortify swiae and poultry diets. The use of these supplements to provide the essential amino acids permits diets with lower total cmde proteia coateat. 

Enzymatic hydrolysis is also used for the preparation of L-amino acids. Racemic D- and L-amino acids and their acyl-derivatives obtained chemically can be resolved enzymatically to yield their natural L-forms. Aminoacylases such as that from Pispergillus OTj e specifically hydrolyze L-enantiomers of acyl-DL-amino acids. The resulting L-amino acid can be separated readily from the unchanged acyl-D form which is racemized and subjected to further hydrolysis. Several L-amino acids, eg, methionine [63-68-3], phenylalanine [63-91-2], tryptophan [73-22-3], and valine [72-18-4] have been manufactured by this process in Japan and production costs have been reduced by 40% through the appHcation of immobilized cell technology (75). Cyclohexane chloride, which is a by-product in nylon manufacture, is chemically converted to DL-amino-S-caprolactam [105-60-2] (23) which is resolved and/or racemized to (24)... 

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. 

Hydroxy-4-methylthiobutyric acid [583-91 -5] the hydroxy analogue of the amino acid methionine, is manufactured by acid hydrolysis of 3-methylthiopropionaldehyde cyanohydrin [17773-41-0] which is produced by the reaction of methyl mercaptan with acrolein (qv). 

Used as a gas odorant used to manufacture methionine, plastics, jet fuel additives, pesticides, fungicides used as a catalyst and as a synthetic flavoring. 

Uses Synthesis of methionine intermediate in the manufacture of pesticides, fungicides. Jet fuels, plastics catalyst added to natural gas to give odor. 

The Daily Industiy. The first step in cheese manufacture is the coagulation of milk. Coagulation can be divided into two distinct phases, enzymatic and the non-enzymatic. In the primary enzymatic phase a proteol ic enzyme such as chymosin (rennet), or less effectively, pepsin, carries out an extremely specific and limited proteolysis, cleaving a phenylalanine-methionine bond of /c-casein, making the casein micelle metastabie. In the second, non-enzymatic phase, the... 

Uses. Intermediate in manufacturing of jet fuels, pesticides, fungicides, plastics synthesis of methionine emission from paper pulp mills, odoriferous additive to natural gas... 

Hazards Associated with Organic Chemical Manufacturing Condensation Process for DL-Methionine Production, Mitre Corp., McLean, VA, Report No. MTR-79W00378-02, April 1980. 

There are 22 different AAs in the body of the bird, 10 of which are essential AA (EAA arginine, methionine, histidine, phenylalanine, isoleucine, leucine, lysine, threonine, tryptophan and valine), i.e. cannot be manufactured by the body and must be derived from the diet. Cystine and tyrosine are semi-essential in that they can be synthesized from methionine and phenyla-... 

The chloride is used to manufacture silicones, tetramethyl lead and triptane (2,2,3 trimethylbutane). Lesser uses include the manufacture of butyl rubber, higher halogenated methanes, methyl cellulose, quaternary ammonium compounds, methyl mercaptan, methionine, fungicides and pesticides (primarily the Me-arsenate herbicides). Recently the chlorinated fluorocarbons have replaced CH3CI as high volume refrigerants and propellants (ref. 32) Tables 12 and 13 list the chemical and physical properties and potential numbers of workers exposed to the monohalomethanes. 

E. coli does not synthesize vitamin Bi2 and grows well without this nutrient. However, in certain circumstances there is a marginal benefit to the cell to be able to manufacture methionine by a pathway involving the vitamin. For this purpose the required apoprotein is synthesized, and the receptor protein is inserted in the membrane in anticipation of finding Bi2 in the environment (70). Phages BF23 and the E colicins have somehow managed to adapt to the Bi2 receptor (71). Besides the surface receptor, a second protein component in the periplasmic space may be necessary for further transport of the vitamin. 

Of the natural amino acids, only methionine is manufactured chemically as the racemic mixture. All other natural types are pro-... 

Amino Acids. Amino acids are produced by both fermentation and biocatalysis for use in animal feed, fertilizer, as flavor enhancers, dietary supplements, and in pharmaceutical manufacture. By volume, the most important products are L-lysine, L-methionine, L-threonine, and L-tryptophan, most of which are produced by fermentation. Biocatalysis still plays an important role in amino acid supply and has been used to synthesize both L- and D-amino acids, including a variety of nonnatural analogues. The major producers are Degussa, Tanabe Seiyaku, and Kyowa Hakko. 

Another type of reactor that may have considerable future potential for use in homogeneous catalytic reactions is called the membrane reactor. These reactors have been successfully used for the commercialization of manufacturing processes based on enzyme catalysis. In fact, 75% of the global production of l-methionine is performed in an enzyme reactor. A membrane is basically an insoluble organic polymeric film that can have variable thickness. The catalyst... 

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