Amino acids L-lysine

Caprolactam is an amide and, therefore, undergoes the reactions of this class of compounds. It can be hydrolyzed, Ai-alkylated, O-alkylated, nitrosated, halogenated, and subjected to many other reactions (3). Caprolactam is readily converted to high molecular weight, linear nylon-6 polymers. Through a complex series of reactions, caprolactam can be converted to the biologically and nutritionally essential amino acid L-lysine (10) (see Amino acids). 

In salt substitutes, the metallic or bitter taste of potassium chloride is often masked by other ingredients, such as the amino acid L-lysine, tricalcium phosphate, citric acid, and glutamic acid. 

A convenient molecule from which to build trifunctionals is the amino acid, L-lysine. Its three functional groups, a-carboxy, a-amino, and e-amino, can be derivatized independently to contain three arms. Each arm can be designed to terminate in a complexing group able to participate in a particular type of conjugation reaction or affinity interaction. 

Amino acids L-lysine, L-tryptophan, L-phenylalanine, glutamic acid Food and feed additives... 

This is a lysyl tRNA synthetase enzyme in the first instance that should have the expected capacity to couple the naturally available amino acid L-lysine to appropriate cognate tRNAs bearing anti-codon sequences complementary to lysine codons (see Section 1.6.1). However in the presence of zinc ions, Zn +, the function of this enzyme becomes altered to catalyse the biosynthesis of diadenosine-5, (Ap4A) followed by... 

EOF- or chemically-induced mobilization of the focused zones past the detector, Guillo et al. illustrated the use of on-chip pumping, generated by elastomeric diaphragm pumps in a three-layer device (one PDMS layer sandwiched by two glass layers), to mobilize the zones. The authors explored the effect of mobilization flow rates on the separation of two amino acids, L-lysine and L-histidine the electropherograms can be seen in Figure 10.12. 

Biosynthesis physiology The Q.a. are built up of two to four cadaverine units formed from the amino acid L-lysine by decarboxylation. The biosynthesis of Q. a of types I and III has been well investigated In lupines the biosynthesis of Q. a. occurs in the chloro-plasts of the leaves. The Q.a. are transported in the phloem to their storage sites flowers, seeds, and epi-... 

Also known as beta-alanine because of its similarity to the canonical amino acid L-lysine, it has been overproduced in E. coli. A strain was prepared, which included an aspartate decarboxylase gene panD) from C. glutamicum, overexpression of aspartase (aspA) and phosphoenolpyruvate carboxylase (ppc), and acetyl-CoA synthase (acs) and it resulted in total titers of 32 g 1 after 39 h from rich media supplemented by glucose and ammonium sulfate [61]. 

L-glutamic acid. Today 1.5 Mio mto a of this amino acid are produced worldwide and predominantly used in food as a flavour-enhancing additive. The essential amino acids L-lysine, L-threonine and L-tryptophan are produced by fermentation for the feed additive market. In 2004 worldwide 770,000 mtoa L-lysin and 65,000 mto a L-threonine were produced by bacterial fermentation. According to Ajinomoto sales of feed additive amino acids grow up to 9% per year. Today Evonik Industries produces feed grade L-lysine, L-threonine and L-tryptophan by large-scale fermentation and produces pharma-grade L-alanine, L-aspartic acid, L-isoleucine, L-proline, L-valine and L-tryptophan for applications in the pharma markets. More products from fermentation are shown in Table 12.2. 

COLCOM (http //www.colcom.eu/uk/index.php and subpages thereof, accessed 8 July 2010) offers polydisperse Dendri-Graft Poly-Lysine, based on the amino acid L-lysine, of generations 1-5 with different surface functionalities. The company also offers diagnostic kits for detection and quantification of the total bacterial flora in water, DENDRIDIAG . 

Amino acids (L-lysine, etc.) specific amino oxidase fermentation substrates... 

Biosynthesis of the amino acid L-lysine is costly for the cell in terms of energy and reduction equivalents. If present in the medium, L-lysine is imported into C. glutamicum by the uptake system Lysl [37]. Surprisingly, L-lysine is also exported out of the C. glutamicum cell by an active transport system [38-40]. The L-lysine export system LysE excretes L-lysine with a Michaelis-Menten constant (Kj j) value of about 20 mM [41]. Since L-lysine biosynthesis is tightly regulated and C. glutamicum cannot catabolize L-lysine, L-lysine accumulates only under conditions of an unbalanced catabolism. 

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