@misc{eprints68069,
           month = {Desember},
           title = {PENGARUH MODIFIKASI KIMIA MENGGUNAKAN SITRAKONAT
ANHIDRIDA TERHADAP STABILITAS ENZIM {\ensuremath{\alpha}}-AMILASE
DARI Aspergillus fumigatus},
          author = {lupiawidya22@gmail.com Lupia Widya Astuti },
         address = {UNIVERSITAS LAMPUNG},
       publisher = {FAKULTAS MATEMATIKA DAN ILMU PENGETAHUAN ALAM},
            year = {2022},
             url = {http://digilib.unila.ac.id/68069/},
        abstract = {ABSTRAK
PENGARUH MODIFIKASI KIMIA MENGGUNAKAN SITRAKONAT
ANHIDRIDA TERHADAP STABILITAS ENZIM {\ensuremath{\alpha}}-AMILASE
DARI Aspergillus fumigatus
Oleh
Lupia Widya Astuti
Kestabilan enzim dalam industri merupakan faktor penting, karena enzim
umumnya tidak stabil pada pH dan suhu ekstrim. Penelitian ini bertujuan untuk
meningkatkan stabilitas enzim {\ensuremath{\alpha}}-amilase dari A. fumigatus dengan modifikasi kimia
menggunakan sitrakonat anhidrida. Proses penelitian dilakukan melalui tahapan
berikut: produksi enzim, isolasi, pemurnian, modifikasi kimia dan karakterisasi.
Aktivitas enzim ditentukan dengan metode Fuwa dan Mandels serta kadar protein
dengan metode Lowry. Hasil penelitian menunjukkan enzim hasil pemurnian
mempunyai pH optimum 5; suhu optimum 50?C; KM = 3,01 mg/mL substrat; Vmaks
= 35,46 {\ensuremath{\mu}}mol/mL.menit, dan uji stabilitas termal pada suhu 60?C selama 100 menit
menunjukkan nilai ki = 0,0179 menit-1; t1/2 = 38,72 menit; dan {\ensuremath{\Delta}}Gi = 104,26 kJ/mol.
Enzim hasil modifikasi menggunakan sitrakonat anhidrida 40 {\ensuremath{\mu}}L memiliki pH
optimum 6 sedangkan 50 {\ensuremath{\mu}}L dan 60 {\ensuremath{\mu}}L memiliki pH optimum 5,5 dengan suhu
optimum ketiga penambahan tersebut adalah 60?C; nilai KM berturut-turut adalah
4,57; 5,03; dan 5,22 mg/mL substrat; nilai Vmaks adalah 27,70; 25,77; dan 25,71
{\ensuremath{\mu}}mol/mL menit. Uji stabilitas termal enzim hasil modifikasi menggunakan
sitrakonat anhidrida 40, 50, dan 60 {\ensuremath{\mu}}L pada suhu 60?C selama 100 menit secara
berturut-turut memiliki nilai ki sebesar 0,0027; 0,0023; dan 0,0021 menit-1; t1/2
sebesar 256,67; 301,30; dan 330,00 menit; dan nilai {\ensuremath{\Delta}}Gi sebesar 109,584; 110,028;
dan 110,279 kJ/mol. Modifikasi kimia enzim {\ensuremath{\alpha}}-amilase dari jamur A. fumigatus
menggunakan sitrakonat anhidrida dapat meningkatkan stabilitas termal sebesar
6,6-8,5 kali. Hal ini dibuktikan dengan penurunan nilai ki dan peningkatan nilai t1/2
dan {\ensuremath{\Delta}}Gi.
Kata kunci: {\ensuremath{\alpha}}-amilase, Aspergillus fumigatus, modifikasi kimia, sitrakonat
anhidrida


The stability of enzymes for industrial usage is important because enzymes are
generally unstable at high pH and temperatures. This work aims to improve the
stability of the {\ensuremath{\alpha}}-amylase enzyme from A. fumigatus by chemical modification
using citraconic anhydride. The following phases were followed in the research
process: enzyme production, isolation, purification, chemical modification, and
characterization. The enzyme activity was then evaluated using the Fuwa and
Mandels methods, and the protein content was assessed using the Lowry method.
The enzyme activity was then evaluated using the Fuwa and Mandels methods, and
the protein content was assessed using the Lowry method. The results showed that
the native enzymes had an optimum pH of 5; optimum temperature 50?C; KM =
3.01 mg/mL substrate; Vmax = 35.46 {\ensuremath{\mu}}mol/mL.min, ki = 0.0179 min-1; t1/2 = 38.72
min; dan {\ensuremath{\Delta}}Gi = 104.26 kJ/mole. The modified enzyme using citraconic anhydride
40 {\ensuremath{\mu}}L has an optimum pH of 6 while 50 {\ensuremath{\mu}}L and 60 {\ensuremath{\mu}}L has an optimum pH of 5.5
and the optimum temperature of three concentrations is 60?C; KM = 4.57, 5.03, and
5.22 mg/mL substrate; Vmax = 27.70, 25.77, and 25.71 {\ensuremath{\mu}}mol/mL.min, respectively.
The modified enzyme thermal stability test with citraconic anhydride 40, 50, and
60 {\ensuremath{\mu}}L at 60?C for 100 minutes yielded ki values of 0.0027, 0.0023, and 0.0021 min-
1, t1/2 values of 256.67, 301.30, and 330.00 min, and {\ensuremath{\Delta}}Gi values of 109.58, 110.03,
and 110.28 kJ/mole. Chemical modification of the {\ensuremath{\alpha}}-amylase enzyme from the
fungus A. fumigatus with citraconic anhydride can increase thermal stability by 6.6-
8.5 times. This is seen by a decrease in the value of ki and increasing the values of
t1/2 and {\ensuremath{\Delta}}Gi.
Keywords: {\ensuremath{\alpha}}-amylase, Aspergillus fumigatus, chemical modification,
citraconic anhydride}
}