Lysine - continued utilization

Biotin is a water-soluble vitamin. It is a cofactor for four ATP-dependent carboxylases acetyl-CoA carboxylase, pyruvate carboxylase, propionyl-CoA carboxylase, and p-methylcrotonyl-CoA carboxylase. Biotin occurs covalently bound to the enzymes via the terminal amino group of a lysine residue. With the normal and continual turnover of these enzymes in the body, the biotin is released, but then utilized again as a cofactor when the enzymes are re-synthesized. The structure of biotin is shown in Figure 9.32,... 

Media employed in traditional plate checks typically include inhibitors and/or stimulators (Table 13.4). Such chemicals might include lysine, a nitrogen source that brewing yeast cannot utilize but wild yeast can copper sulfate, which is also inhibitory to strains of Saccharomyces or plates containing Actidione, which selectively promotes bacterial growth. Such techniques typically require a two-day 25° incubation period (EBC Analytica Microbiological Part 11 Continued, 1984). 

The economic importance of amino acids is noteworthy consequently, demand is continually growing for their utilization as food additives, feed supplements, therapeutic agents and precursors for the synthesis of peptides or agrochemicals. L-Glutamic acid is the highest produced amino acid (approximately 900000 tonnes per year) followed by L-lysine (420000 tonnes per year). Lysine is an essential amino acid and belongs to the aspartate biosynthetic pathway. Lysine can be produced by fermentation of bacteria or their mutants [2, 3]. For nearly 50 years, constant efforts to increase production performance have been carried out, both directed towards the microorganisms themselves and towards technical improvements of the respective processes [4]. Corynebacterium... 

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