PENINGKATAN STABILITAS ENZIM α-AMILASE DARI Aspergillus fumigatus DENGAN MODIFIKASI KIMIA MENGGUNAKAN DIMETILADIPIMIDAT
| Main Author: | NURMALA , 1517011136 |
|---|---|
| Format: | Bachelors NonPeerReviewed Book Report |
| Terbitan: |
FAKULTAS MATEMATIKA DAN ILMU PENGETAHUAN ALAM
, 2019
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| Subjects: | |
| Online Access: |
http://digilib.unila.ac.id/59945/1/ABSTRAK.pdf http://digilib.unila.ac.id/59945/3/SKRIPSI%20FULL.pdf http://digilib.unila.ac.id/59945/4/SKRIPSI%20TANPA%20BAB%20PEMBAHASAN.pdf http://digilib.unila.ac.id/59945/ |
Daftar Isi:
- Enzim merupakan biokatalisator yang diaplikasikan secara luas pada bidang industri. Pemanfaatan enzim dalam industri memiliki kriteria yang harus dipenuhi yaitu mempunyai kestabilan termal yang tinggi. Oleh karena itu, perlu dilakukan penelitian mengenai peningkatan stabilitas enzim. Pada penelitian ini untuk meningkatkan kestabilan enzim dilakukan modifikasi kimia menggunakan dimetiladipimidat (DMA). Tahap penelitian ini meliputi proses isolasi enzim, pemurnian enzim, modifikasi enzim, serta karakterisasi enzim hasil pemurnian sebelum dan setelah modifikasi. Hasil menunjukkan enzim α-amilase hasil pemurnian mempunyai aktivitas spesifik sebesar 7.010,42 U/mg yang kemurniannya meningkat 7 kali dibandingkan dengan ekstrak kasar. Enzim α-amilase hasil pemurnian mempunyai pH 5,5; suhu optimum 55 oC; nilai KM = 1,95 mg/mL substrat dan nilai Vmaks = 109,36 μmol/mL.menit. Uji stabilitas termal enzim α-amilase hasil pemurnian pada suhu 55 oC selama 60 menit mempunyai aktivitas sisa sebesar 17,17 % dan memiliki nilai t1/2 = 25,86 menit; ki = 0,0268 menit-1; dan ΔGi = 113,69 KJ/mol. Enzim yang telah dimodifikasi menggunakan DMA dengan variasi konsentrasi 0,5; 1; dan 1,5 % mempunyai pH 5,5 dan suhu optimum 65 oC nilai KM = 1,24; 1,42; dan 1,91 mg/mL substrat dan nilai Vmaks = 22,92; 35,77; dan 51,10 μmol/mL.menit. Uji stabilitas termal enzim hasil modifikasi pada suhu 65 oC selama 60 menit mempunyai aktivitas sisa sebesar 59,16; 46,18; dan 34,43 % serta memilki nilai t1/2 = 85,55; 58,25; dan 37,46 menit; nilai ki = 0,0081; 0,0119; dan 0,0185 menit-1; dan nilai ΔGi = 117,09; 116,02; dan 114,80 KJ/mol. Penurunan nilai ki serta peningkatan t1/2 dan ΔGi menunjukkan bahwa enzim hasil modifikasi menggunakan DMA lebih stabil dibandingkan dengan enzim hasil pemurnian. Kata kunci: α-amilase, Aspergillus fumigatus, Dimetiladipimidat. abstract Enzymes are biocatalysts which are widely applied in the industrial field. The use of enzymes in industry has certain condition, has a high thermal stability. Therefore, research is needed to improve the stability of enzyme. In this study to improve the stability of the enzyme, chemical modification was carried out using dimethyladipimidate (DMA). The stages of this study include the isolation, purification, modification, and characterization of the purified enzyme before and after modification. The result showed that the α-amylase after purification had a spesific activity of 7,010.42 U/mg whose purity increased 7 times compared to crude extract. The purified enzyme had a pH of 5; optimum temperature of 55 oC; KM = 1.95 mg/mL substrate; and Vmax = 109.36 μmol/mL.minute. Thermal stability test of the purified enzyme had residual activity of 17.17 % and value of t1/2 = 25.86 minutes; ki = 0.044 minute -1; and ΔGi = 101.885 KJ/mol. The enzyme that had been modified using DMA with a concentration variation of 0.5; 1; and 1.5 % had pH of 5.5 and optimum temperature of 65 oC; respectively had KM = 1.24, 1.42, and 1.91 mg/mL substrate; Vmax = 22.92, 35.77, and 51.10 μmol/mL.minute. Thermal stability test of the modified enzyme with a concentration variation of 0.5; 1 and 1.5 % had residual activity, respectively 59.16 , 46.18 , dan 34.43 % and had value of t1/2 = 85.55, 58.25, and 37.46 minutes; ki = 0.0081, 0.0119, and 0.0185 minute-1; and also ΔGi = 117.09, 116.02, and 114.80 KJ/mol. A decrease in ki, an increase in half-life (t1/2) and ΔGi indicate that the modified α-amylase enzyme using DMA is more stable than the purified enzyme. Keywords: α-amylase, Aspergillus fumigatus, Dimethyladipimidate.