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Alanine

L-alanine is an important amino acid. It is used as a starting material for pharmaceuticals and foods and has other uses in the chemical industry. Its demand has abruptly increased in recent years. L-alanine is used in pharmaceutical and veterinary applications. For example, it is included, together with other amino acids, in preparations for parenteral administration as clinical preoperative and postoperative foods, as well as an animal feed supplement. Furthermore, alanine is used as a food additive on account of its sweet taste. It is well-known that certain amino acids play a critical nutritional role in muscle development and performance. For example, skeletal muscle serves as a major site of branched chain amino acid metabolism. Also, alanine is released from working muscle in large amounts. This alanine is synthesized within the muscle by the transamination of pyruvate and glutamate. The pyruvate is derived from exogenous glucose or muscle glycogen. Once released from the muscle, the newly synthesized alanine is transported to the liver where it is deaminated resulting in the reformation of pyruvate. This constitutes the glucose-alanine cycle which is primarily responsible for transporting toxic ammonia from the working muscle in the form of alanine to be disposed of as urea. L-alanine is produced industrially by the decarboxylation of L-aspartate by means of immobilized cells or cell suspensions of Pseudomonas dacunhae. D/L-alanine can also be prepared by chemical synthesis or by the direct fermentation of sugars.

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