Author/Authors :
hassan, mohamed e. national research center - center of excellence - chemistry of natural and microbial products department, encapsulation nano-biotechnology group, Cairo, Egypt , ibrahim, ahmed galal al azhar university - faculty of science - chemistry department, Cairo, Egypt , abd el-wahab, h. al azhar university - faculty of science - chemistry department, Cairo, Egypt , abdel hai, farag al azhar university - faculty of science - chemistry department, Cairo, Egypt , mahmoud, hamza al azhar university - faculty of science - chemistry department, Cairo, Egypt , awad, ghada e. a. national research center - center of excellence - chemistry of natural and microbial products department, encapsulation nano-biotechnology group, Cairo, Egypt
Abstract :
Alginate / H0 (acrylamide-co-acrylic acid) gel beads was generated and modified by sequential soaking with polyethyleneimine (PEI) and glutaraldehyde (GA) as a functional carrier suitable for enzymes immobilization. The modification was carried out by using response surface methodology. Maximum immobilization yield (78.2%) of β- galactosidase was obtained by soaking the gel beads with 3.5% of (PEI) for 5hrs. followed by soaking the treated gel beads with 4 % of (GA) for 6hrs. Analysis of variance (ANOVA) showed a high coefficient of determination value (R^2) of 0.90, ensuring a satisfactory adjustment of the quadratic model with the experimental data. Thermo gravimetric analysis (TGA) of gel beads during different improvement steps showed a remarkable increase in their thermal stability from 190, 200 and 210 °C for Alginate-H0, Alginate-H0 / PEI and Alginate-H0 / PEI / GA respectively. The reusability test proved the durability of the modified Alginate / H0 (acrylamide-co-acrylic acid) gel beads for 7 cycles with retention of 100% of the immobilized enzyme activity losing only 10% of its activity after 17 cycles. To be more convenient for industrial uses, considerable stability and reusability of bound enzyme maybe advantageous for its industrial application.
Keywords :
Alginate , Acrylamide , Immobilization , Modification , Response surface methodology
