The Effect of Zeolite/Chitosan Hybrid Matrix for Thermal-stabilization Enhancement on the Immobilization of Aspergillus fumigatus α-Amylase

Yandri Yandri (Department of Chemistry, Lampung University, Lampung,)
Hendri Ropingi (Department of Chemistry, Lampung University, Lampung,)
Tati Suhartati (Department of Chemistry, Lampung University, Lampung,)
John Hendri (Department of Chemistry, Lampung University, Lampung,)
Bambang Irawan (Department of Biology, Lampung University, Lampung,)
Sutopo Hadi (Department of Chemistry, Lampung University, Lampung,)

Emerging Science Journal
Vol 6, No 3 (2022): June

In this paper, the A. fumigatus α-amylase had been immobilized onto zeolite/chitosan hybrid to improve its thermal-stabilization for industrial needs. The methods applied enzyme production, isolation, partial purification, immobilization, and characterization. The optimum temperatures of the native and immobilized enzymes were 50 and 55˚C, respectively. The native enzyme has KM of 3.478 ± 0.271 mg mL-1 substrate and Vmax of 2.211± 0.096 µmole mL-1 min-1, while the immobilized enzyme has KM value of 12.051 ± 4.949 mg mL-1 substrate and Vmax of 1.602 ± 0.576 µmole mL-1 min-1. The residual activity of the immobilized enzyme retained up 10.97% after fifth reuse cycles. The native enzyme has ΔGi of 104.35 ± 1.09 kJ mole-1 and t½ of 38.75 ± 1.53 min, while the immobilized enzyme has ΔGi of 108.03 ± 0.05 kJ mole-1 and t½ of 180.03 ± 3.31 min. According to the increase in half-life (t½), stability improvement of the A. fumigatusα-amylase was 4.65 times greater than the native enzyme. Thus, the zeolite/chitosan hybrid is used as a new supporting matrix for further enzyme immobilization to stabilize the enzymes. Doi: 10.28991/ESJ-2022-06-03-06 Full Text: PDF