Immobilization of \(STARGEN^{TM}002\) on Amine-Glutaraldehyde Modified Silica and Its Enzymatic Properties Zico Daniel Despen Sihombing (a), Vilda Afrilia Dwi Nanda (a), Handajaya Rusli (a*), Ihsanawati (b), Dessy Natalia (b)
(a) Analytical Chemistry Research Division, Faculty of Mathematics and Natural Sciences, Bandung Institute of Technology. Jl. Ganesha 10, Bandung, Indonesia.
*handajaya[at]itb.ac.id
(b) Biochemistry Research Division, Faculty of Mathematics and Natural Sciences, Bandung Institute of Technology. Jl. Ganesha 10, Bandung, Indonesia.
Abstract
\(STARGEN^{TM}002\) is an industrial enzyme widely used to hydrolyze starch, producing glucose, maltose, and maltodextrin. The usage of \(STARGEN^{TM}002\) in the starch processing industry has limitation due to its stability and non-reusable properties. Therefore, enzyme immobilization has become a powerful tool to overcome these problems. The purpose of this study was to immobilize \(STARGEN^{TM}002\) to amine-glutaraldehyde modified silica and determine the enzymatic characterization. A silica was synthesized using the Stober method and further modified with propylamine and propyldiethylenetriamine. Both modified silica were then used to immobilize \(STARGEN^{TM}002\) using glutaraldehyde as a crosslinker. All activities of free and immobilized enzymes towards soluble starch were carried out using the 3,5-dinitrosalicylic acid (DNS) method, while the amount of proteins was determined using the Bradford method. The optimum pH of free and immobilized enzymes were 6.5 at an optimum reaction temperature of 60\(^{o}C\) with 2%-w/v of soluble starch. The immobilized enzyme still exhibited the activity up to the 7\(^{th}\) use with the remained specific activity of 38 and 41% for silica propylamine and silica propyldiethylenetriamine, respectively. At optimum conditions, the specific activity of the free enzyme was 7.59 U/mg. However, the immobilized enzyme by silica propylamine and by silica propyldiethylenetriamine was 8.57 and 9.31 U/mg, respectively, indication for increasing the enzyme stability and activity. Taken together, the immobilized \(STARGEN^{TM}002\) with the amine-glutaraldehyde modified silica are promising for industrial applications.
