Figure 1.
Schematic illustrations for the preparation of CLGNs, glucoamylase immobilization, and temperature-triggered enzyme release.
The gelatin and glucoamylase were mixed together before the cross-linking step in the entrapment method. In the adsorption method, the enzyme was adsorbed after the formation of the CLGNs.
Table 1.
Temperature-Sensitive Response for Different Anions Modified CLGNs.
Figure 2.
Temperature responses effect of CLGNs.
(A) Pictures of CLGNs at different temperatures. (B) Size distribution of CLGNs at different temperatures measured using DLS. (C) Size changes of CLGNs at 25°C and 45°C within three cycles.
Figure 3.
(A) negative stained by phosphotungstic acid and (B) gluocoseamylase immobilized CLGNs prepared by adsorption method.
Table 2.
Reversible Temperature-Triggered Swelling Degree of the CLGNs, gulocoseamylase immobilized CLGNs prepared by entrapment and adsorption methods respectively.
Figure 4.
(A) Zeta potential measurements values of the CLGNs under different temperature. (B) IR spectra of lyophilized CLGNs. Spectra of pure gelatin were also presented for comparison.
Table 3.
Glucoamylase Immobilization Efficiency by Adsorption Method Using Dialyzed and Non-dialyzed CLGNs at Different Temperature.
Figure 5.
Activities of the glucoamylase at different temperature.
(A) 30 mg of dialyzed and lyophilized powder was added into 3 mL of 1.0 mg/mL glucoamylase solution to perform the adsorption of enzyme at 60°C for four hours and then at 25°C for one hour. After centrifugation and washing process to remove free enzyme, the sedimentation of CLGNs were incubated at different temperature to determine the activities of released enzyme. The activities of free glucoamylase were also calculated at the same condition for comparison. (B) Comparison of enzyme activities for the released glucoamylase at 60°C and free enzyme at temperature range of 30–85°C a: Data are compared with the data of released enzyme at 40°C and significantly different (P<0.05) from that data; b: Data are compared with the data of free enzyme at 85°C and significantly different (P<0.05) from that data.