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Poster Presentation 6-37
Hydrophobic Adsorption of Reactants and Products of Enzymatic Synthesis of Ampicillin on Different Resins
Marcelo F. Vieira; Marlei Barbosa, Raquel L C. Giordano
Departamento de Engenharia Química - Universidade Federal de São Carlos Via Washington Luiz, Km 235 - CEP:13565-905 -São Carlos – SP – Brasil
Telephone: (55-16) 260 8264; Fax: (55-16) 260 8266; Email: raquel@deq.ufscar.br
The performance of the resins Amberlite® XAD-4 and XAD-7, and Duolite® XAD-761 for the adsorption of ampicillin (AMPI), D-phenylglycine (PG), D-phenylglycine methyl ester (EMPG) and 6- aminopenicillanic acid (6-APA) was evaluated. These molecules are present in the enzymatic synthesis of ampicillin. Adsorption yields at pH 6.5 were about 10% higher at 4°C than at 25°C. The influence of pH on adsorption was evaluated for the range 4.5-8.5, at 25°C and 4°C. Increasing pH values led to an increase of the yield for EMPG, whereas for AMPI and 6-APA the opposite effect was noticed for the three resins. PG yield was not influenced by pH. The highest selectivity was obtained using XAD-4. Experimental adsorption isotherms were obtained for these three resins, at different pHs. Linear, Freundlich and Langmuir models were fitted to experimental data. The best model to represent adsorption equilibrium in each condition was discriminated.
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