Abstract
The amino acids are produced usually by the fermentation as mixtures, which may be regarded as cations or anions according to the pH of the solution. The electrodialysis with ion-exchange membranes seems to be a very useful method to separate a desired amino acid from mixed amino acids. However, there has been no such study on a quantitative basis. In this work, using a glycine (Gly) as a typical amino acid, we studied the variation of the flux (J) of Gly as a function of pH during the electrodialysis and found that the flux of Gly was maximum at pH ≒ 3. It was also found that the relationship between the electric current density (I) and the flux of the total cations (JGly+H) was represented by a straight line through the origin when the concentration of Gly and pH were kept constant. It was evident that JGly+H was constant as long as I and pH were kept constant, independently of the concentrations of Gly.
