Selective separation of amino acids with a charged inorganic nanofiltration membrane: Effect of physicochemical parameters on selectivity

• Published in: Biotechnology and bioengineering Vol. 54; no. 4; pp. 291 - 302
• Main Authors: Garem, A., Daufin, G., Maubois, J. L., Léonil, J.
• Format: Journal Article
• Language: English
• Published: Hoboken Wiley Subscription Services, Inc., A Wiley Company 20.05.1997; Wiley
• Subjects: amino acid; Biological and medical sciences; Biotechnology; charged membranes; Fundamental and applied biological sciences. Psychology; Life Sciences; Methods. Procedures. Technologies; nanofiltration; Others; physicochemical parameters; selectivity; Various methods and equipments; Charge density; Separation method; Nanofiltration; Ionic strength; Aminoacid; Concentration effect; Membrane filtration; pH; Environmental factor; Membrane; Selectivity; Sodium Chlorides; METHODE DE SEPARATION
• ISSN: 0006-3592; 1097-0290
• DOI: 10.1002/(SICI)1097-0290(19970520)54:4<291::AID-BIT1>3.0.CO;2-F

A charged organic‐inorganic nanofiltration (NF) membrane prototype was used to separate a mixture of nine amino acids (AA) on the basis of differential electrostatic interactions with the membrane because, for a given pH, some of them were positively charged, some were negative, and some were zwitterions. Effect of pH, amino acid concentration (Cr), and added ionic strength ([NaCI]) on the process selectivity was studied. A global statistical study revealed that pH was the dominant parameter regarding fractionation. Cr and [NaCI] had a weaker effect, but the ratio Cr/[NaCI] demonstrated a pronounced effect on system selectivity. Two split‐ups of the mixture were obtained at pH 2 and at pH 12, for a 1‐g/L total AA concentration and a Cr/[NaCI] ratio of 0.16. Under these conditions, the differences in transmissions between basic and acid AA were higher than 70%. Interpretation of the results according to the Donnan theory allows us to foresee the potentialities of charged nanofiltration membranes for the fractionation of a complex mixture, such as peptidic hydrolysate to streams containing peptides and amino acids having different isoelectric points. © 1997 John Wiley & Sons, Inc. Biotechnol Bioeng 54: 291–302, 1997.