IMMOBILIZATION OF ?-AMILASE FROM BACILLUS AMYLOLIQUIFACIENS ON MODIFIED SILICA USING 3-AMINOPROPYLTRIETHOXYSILANE (APTES) AND GLUTARALDEHYDE

• Main Author: Pravida Irlitashanty, Agnes
• Format: Final Project
• Language: Indonesia
• Subjects: Kimia
• Online Access: https://digilib.itb.ac.id/gdl/view/49135
• Institution: Institut Teknologi Bandung

?-amylase is widely used in industries due to its function in hydrolyzing starch to glucose and glucose-based oligomers. Glucose is an important precursors in many types of chemical reactions and glucose-based oligomers play insight roles in food and health industries. Enzyme in liquid form is impossible to use repeatedly, thus will increase the production cost. To solve this problem, the enzyme is immobilized on a matrix. Immobilization is a technique to restrict the movement of an enzyme in a matrix for repeatable use. The objective of this research is to immobilize ?-amylase from Bacillus amyloliquefaciens on a matrix by covalent bonding. The matrix is silica modified using 3-aminopropyl triethoxysilane (APTES) and glutaraldehyde. Synthesis silica matrix is carried out simultaneously with modification using APTES. The optimum composition for silica-APTES was 10,30% (v/v) H2O; 5,29% (v/v) NH3; 64,38% (v/v) isopropanol; 18,03% (v/v) TEOS; and 2,00% (v/v) APTES. Modification of silica-APTES with glutaraldehyde is carried out using 15 mL of glutaraldehyde for each 3.5 grams of silica-APTES. Based on the FTIR spectrum, peaks at wavenumber 900-1100 cm-1 for the presence of a Si-O-Si bonds, peaks at wavenumber 1600 cm-1 for the presence of NH bonds and peaks at wavenumber 3000-3300 cm-1 for the OH bond are observed. The color of the matrix also changes from white to red, so it can be concluded that modification with glutaraldehyde has been successfully carried out. The bioinformatics study showed that ?-amylase have many positive charged amino acids that can interacted with glutaraldehyde. Optimization of ?-amylase contact time with silica modified with APTES and glutaraldehyde matrix is carried out in acetate bufer 0.1 M, pH 5 and room temperature with time range between 30-720 minutes. The optimization results of ?-amylase contact time with silica modified with APTES and showed the highest results at 30 minutes, but still have the possibility below 30 minutes. Reusability test for immobilized ?-amylase showed the activity is 96.3493% compared to initial activity. Based on these research results, it can be concluded that the immobilization process was successfully done and have potential reusable.