Immobilization impact of GEG-Alg-SPI as a carrier for Aspergillus niger MK981235 inulinase: Kinetics, thermodynamics, and application

Abstract

Box-Behnken design (BBD) was used to develop a substantial carrier for Aspergillus niger MK981235 inulinase using gellan gum (GEG)-alginate (Alg)-soy protein isolate (SPI) as a carrier. With Alg 1.09 %, SPI 1.01 %, polyethyleneimine (PEI) 1.5 %, and PEI pH 7.00, glutaraldehyde (GA) concentration 5 %; GA activation time 45 min as preparation conditions, the maximum inulinase activity recovery percent (60 %) was attained. At 40, 50, and 60 °C, the T1/2 (half-life) and D-values (decimal reduction time) of GEG-Alg-SPI immobilized inulinase were 5.55, 4.78, and 5.11-fold higher than the native form, respectively. The immobilization process enabled the reuse of the enzyme for 20 cycles. The enzyme’s shelf stability also emphasized the success of the immobilization process in preserving the enzyme at 4 °C for 2 months. GEG-Alg-SPI immobilized inulinase succeeded in the hydrolysis of 61.8 % of 2 % inulin into fructose after 7 h.