Chapter 3 - Amino Acids and Nucleic Acid-Related Compounds

Abstract

This chapter reviews trends of researches from 1978 to 1981 according to the following classification: (1) direct fermentation method, (2) precursor addition method, and (3) enzymatic method. It focuses on the production of amino acids. Almost all kinds of amino acids are now available at reasonable prices due to the industrial development of microbial production of amino acids. At present, depending on their industrial supply, amino acids are employed in a diversified field. Utilization of the acids is still expanding based on their physiological properties. The major progress to be made in amino acids fermentation is economical and industrial production of L-tryptophan and L-methionine. Efforts are made aiming at the establishment of these fermentation and also at the improvement of amino acids or nucleosides fermentation, which are now industrially carried out. The improvement of the process control of fermentative production of amino acids and nucleic acid-related compounds has also been pushed forward in relation to agitation-aeration problems. The investigations in the field of amino acids fermentation and the industrial production of L-tryptophan and L-methionine lead to microbial breeding or isolation of microbe, application of inexpensive raw materials, and optimization of fermentation process. Recent trends of this investigation is the application of DNA recombination technique to microbial breeding, the utilization of Cl-compound as a raw material, and the introduction of immobilized enzyme (cell) to fermentation process.