Synthesis of esters using a nylon-immobilized lipase in batch and continuous reactors.
Direct esterifications using a nylon-immobilized lipase from Candida cylindracea were carried out in batch and continuous-flow reactors. The immobilized enzyme was effective in catalyzing the synthesis of ethylpropionate, isoamylpropionate, and isoamylbutyrate. With ethanol dissolved in hexane as a substrate, the maximum initial esterification rate was 0.02 mole/(h x g of immobilized protein), but the enzyme was stable only when the substrate concentrations were lower than 0.2 M. With isoamyl alcohol in hexane as a substrate, esterification rates as high as 0.085 mole/(h x g of immobilized protein) were observed and the immobilized enzyme was stable over a much broader concentration range. However, in this case, the use of a solvent, such as hexane, was not necessary for esterification, and the enzyme could be employed in equimolar acid/alcohol mixtures. A packed-bed reactor was operated successfully for the continuous synthesis of esters. The reactor was stable for long periods of time, and the steady-state performance could be accurately predicted on the basis of batch reaction experiments.
Department of Chemical Engineering, University of Virginia, Charlottesville 22903-2442.
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Carta
J L
JL
Gainer
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ME
Gibson
D002175:Candida / Q000201:enzymology; D004800:Enzymes, Immobilized / Q000378:metabolism*; D004952:Esters / Q000138:chemical synthesis*; D007700:Kinetics; D008049:Lipase / Q000378:metabolism*; D009757:Nylons; D013816:Thermodynamics
D004800:Enzymes, Immobilized; D004952:Esters; D009757:Nylons; D008049:Lipase