Agarose Hydrogel Beads: An Effective Approach to Improve the Catalytic Activity, Stability and Reusability of Fungal Amyloglucosidase of GH15 Family

• Published in: Catalysis Letters 2018, Vol.148 (9), p.2643
• Main Authors: Pervez, Sidra, Nawaz, Muhammad Asif, Aman, Afsheen, Qayyum, Sadia, Nawaz, Faiza, Qader, Shah Ali Ul
• Format: Report
• Language: English
• Subjects: Amylases; Glucose
• ISSN: 1011-372X
• DOI: 10.1007/s10562-018-2460-y

This study deals with the immobilization of amyloglucosidase within agarose using method of entrapment. Enzyme was produced from Aspergillus fumigatus KIBGE-IB33 and then partially purified using 40% ammonium sulphate saturation. Using 40 gl.sup.-1 concentration of agarose and adjusting 3.0 mm size of hydrogels, maximum entrapment yield (78%) was obtained. The kinetic behavior was slightly changed after immobilization as reaction time and reaction temperature increases from 5.0 min (soluble) to 10.0 min (immobilized) and 60 °C (soluble) to 65 °C (immobilized), respectively while, pH optima remained same (pH 5.0). Substrate saturation kinetics revealed that K.sub.m was increased from 1.47 to 4.215 mg ml.sup.-1 while, the value of V.sub.max decreased from 947 to 611 kU mg.sup.-1 for soluble and entrapped amyloglucosidase, respectively. The stability profile of amyloglucosidase also significantly improved after entrapment in agarose hydrogels at 50, 60 and 70 °C for 120 min with retention of 77, 59 and 25% residual activity, respectively. Furthermore, the t.sub.1/2 of soluble and immobilized amyloglucosidase at 60 °C was 167 and 375 min respectively. Due to increase in reusability for various subsequent cycles of entrapped amyloglucosidase, about 8.73 mg ml.sup.-1 increase in glucose production was observed as compared to soluble enzyme.