Estudio Cinético de la reacción de hidrólisis de lecitina de soja pura en polvo con fosfolipasa A2 inmovilizada

MAROTO B., CAMUSSO C., ZARITZKY N.

GRASAS Y ACEITES

INST GRASA SUS DERIVADOS

Lugar: Sevilla; Año: 2001 vol. 52 p. 33 - 37

0017-3495

Immobilized A2 phospholipase enzyme promotes the hydrolytic reaction of pure powder soybean lecithin releasing a mole of fatty acid from C-2 position. The main purpose of this paper was to determine the kinetic parameters of this reaction when the enzyme was adsorbed on alumina or DEAE-sephadex. The best conditions for the reaction were: temperature: 45-48ºC, Ca ions concentration: 6mM, pH: 8,65. Tested conditions for substrate concentration were: 6,3; 12,7;19 and 25 mM working in a batch type reactor and with the immobilized enzyme. The incubating time did not change the enzymatic activity.The hydrolytic activity of alumina or DEAE-sephadexadsorbed A2 phospholipase enzyme was lower than of the soluble enzyme because the intrinsic properties are modified by immobilization. For substrate concentrations ranging between 6 and 19 mM first order kinetic velocity constants were k = 9, 88. 10-2 min-1 and k = 1,766. 10-1 min-1 for alumina and DEAE sephadex respectively. For the same supports but at higher substrate concentration (25mM) the zero order kinetic velocity constants were k= 1,62. 10-3 mol.l-1. min-1 (alumina) and k = 3,58.10-3 mol.l –1.min-1 (DEAE-sephadex).