1999 年 57 巻 4 号 p. 323-333
D-Alanine and n-tartaric acid are widely used for the intermediate of pharmaceuticals, the food additives, chiral building blocks and the resolving agents, etc.
The industrial manufacturing method was not known in about year of the 1985 though D-alanine manufacturing method was researched by various methods. We designed the new, industrial manufacturing method by which selective assimilable ability of the microorganism was used.
That is, the whole quantity L-alanine is assimilated if the microorganism which can assimilate L-alanine as a carbon source is cultured with DL-alanine medium, the organism in the medium becomes only D-alanine substantially, and the purpose is achieved to isolate of D-alanine from this medium. The merit of this method is a thing that D-alanine of a high optical purity can be manufactured from an easy operation. Candida was selected as a microorganism which agreed with the purpose and selective assimilation method was established as an industrial manufacturing method.
As for the research of the industrial manufacturing method of D-alanine, after 1986 when it began to show signs, that demand expands as a medium of the sweeteners, it becomes active and an excellent manufacturing method in the fermentation and the enzymatic method has been developed.
The selective assimilation method does not limit to D-alanine and be advantageous as the general manufacturing method of unnatural type amino acid. In addition, it is possible to apply also to the manufacturing method of unnatural type oxy acids such as n-tartaric acid.