IMMOBILIZATION OF ?-AMYLASE FROM BACILLUS AMYLOLIQUEFACIENS ON THE MODIFIED SILICA WITH N-[3-(TRIMETHOXYSILYL)PROPYL]ETHYLENDIAMINE

• Main Author: Oktaviana, Messy
• Format: Final Project
• Language: Indonesia
• Subjects: Kimia
• Online Access: https://digilib.itb.ac.id/gdl/view/49134
• Institution: Institut Teknologi Bandung

Generally, enzymes exhibit water-soluble characteristics and are used for single process only if they are not immobilized. One of the most widely used enzymes in industry is ?-amylases. This enzyme hydrolyzes ?-1,4-glycosidic linkages in starch to produce simple sugars, such as glucose, maltose, and dextrose. Covalent bonding between enzyme and matrix is one of the common techniques in immobilization. The Immobilization could improve the endurance or stability of enzymes, easy to control the reaction condition and make it possible to use repetitively. The aims of this research are to immobilize ?-amylase from Bacillus amyloliquefaciens to modified silica with N-[3-(Trimethoxysilyl)propyl]ethylendiamine (N-TMSPen) and glutaraldehyde, to optimize the contact time between enzyme and the silica matrix, and to determine the enzyme activity for repetitive used. Silica was synthesized for 6 hours without heating using tetraethyl orthosilicate (TEOS) as precursors, then was modified using N-TMSPen, followed by glutaraldehyde. FTIR spectrum shows peaks of O-H bonds at the wavenumber between 3200?3550 cm?1, Si-O-Si bonds at wavenumber between 1000– 1130 cm?1 and Si-OH bonds at wavenumber between 810?950 cm?1. FTIR spectrum do not show the changes between the silica matrix, before and after glutaraldehyde addition. However, a physical change was detected that the silica color changes from white to yellow. ?-amylase in 0.1 M acetate buffer pH 5 is then immobilized into the modified silica. Several contact time, 0.5, 1, 3, 6, 9 and 12 hours, respectively between enzyme and the matrix was evaluated and 0.5 hours is the best contact time. Activity was done using starch 0.2% in 0,1 M acetate buffer pH 5 as a substrate for 15 minutes reaction time. Analysis of the model structure of the enzyme indicates that decreasing of activity can be caused by the reactions of amino acid surrounding the catalytic pocket with the matrix. The amine groups surrounding the catalytic pocket could be easily reacted with glutaraldehyde from the matrix. The success of ?-amylase immobilization is potential to be used in starch processing industries.