Study On The Separation Process Of L-tryptophan

L-tryptophan is a kind of necessary amino acid. It is useful for growth of people and animal. There are several production methods of L-tryptophan, ultimately only L-tryptophan production by fermentation proved commercially feasible. Therefore, increasing the production and extraction of L-tryptophan is the problem that is in need of settled at present. L-tryptophan extraction technology is studied mainly in this paper. The fermentation broth were added with APAM, and then filtered or centrifuged to remove bacterial cells or protein. One cation exchanger was selected out for L-tryptophan from aqueous solution by comparing thrmodynamic and kinetic properties among fourteen ion- exchanger and adsorption resins. It had stronger adsorption capacity for L-trvptophan when pH was between 6 and 8. The clean filtrate was treated with 003 X 7 resins to be separation, Dynamic test of cation exchanger showed that the saturated adsorption capacity kept almost constants When the flow rate stayed lmL/min.The adsorption efficiency achieved 97.54%.then 0.025mo1/l and 2mol/l amino acid were passed through the ion-exchange column. The effluent fractions of L-tryptopban were dried in vacuo. The rough production was solved by heated 60% ethanol. The solved liquid was treated with D3012 resins to be decolored. The clean liquid was dried in vacuo. Then ethanol was added to the syrup, for crystallization of L- tryptophan at 4 0C. Finally, dried up in a desiccator. The total yield of L-tryptophan was about 68% and purity was 98.2% in the process.