Sj. Ge et Lx. Zhang, CONTROL OF THE DEGREE OF HYDROLYSIS OF A PROTEIN MODIFICATION WITH IMMOBILIZED PROTEASE BY THE PH-DROP METHOD, Acta biotechnologica, 13(2), 1993, pp. 151-160
A mathematical model, DH = 1/k(10(-2DELTApH) - 1), between the pH-drop
(DELTApH) and degree of hydrolysis (DH) of an enzymatic modification
of casein was developed to assess the DH in a packed-bed column reacto
r by directly monitoring the pH value of the modified protein system.
It was demonstrated that the linear DH range and the k value of the eq
uation were dependent on the reactor type and the specificity of the p
roteolytic enzymes immobilized on chitin used in the present study, bu
t no effect of the substrate casein concentration on the linear DH ran
ge was observed. Since DH and DELTApH values of the modified casein co
rrelated with the flow rate in a packed-bed column reactor, it was sug
gested that the DH value, in a considerably wide range of casein modif
ication with a certain immobilized protease in a column reactor, could
be controlled by adjusting the flow rate of the substrate and monitor
ed by a pH-meter. This relationship might be used as a basis for scale
-up and long-term operation of enzymatic modification of proteins by i
mmobilized protease in a column reactor.