ISSN:
0006-3592
Keywords:
nanofiltration
;
selectivity
;
amino acid
;
charged membranes
;
physicochemical parameters
;
Chemistry
;
Biochemistry and Biotechnology
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Biology
,
Process Engineering, Biotechnology, Nutrition Technology
Notes:
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.
Additional Material:
5 Ill.
Type of Medium:
Electronic Resource
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