
Orientation Controlled Immobilization Strategy 267
FIGURE 6 Effect of substrate's temperature (ºC) on beads catalytic activity.
EFFECT OF SUBSTRATE'S PH
The similar behavior of the immobilized enzyme to the free one has been observed
in respond to the changes in the substrate's pH (Figure 7). The optimum pH has not
shifted, but the immobilized enzyme shows higher activity within acidic region, pH
2.5–3.0. This resistance to pH could be explained due to the presence of negatively
charged free carboxylic groups unbinding by calcium ions. This result is in accordance
with those obtained by other authors [29].
FIGURE 7 Effect of substrate's pH on ...