TY  - GEN
CY  - FAKULTAS MATEMATIKA DAN ILMU PENGETAHUAN ALAM
ID  - eprints29886
UR  - http://digilib.unila.ac.id/29886/
A1  - DIANI ISKA MIRANTI, 1217011015
Y1  - 2017/12/27/
N2  - This research aims to study the effect of addition sorbitol toward stability cellulose
enzyme from Rhizopus oryzae. To approach this aims, the enzyme has been done
to produce, to isolate and to purify. The purification of cellulose enzyme was
done by fractination using the ammonium sulfat and dialysis. The purified enzyme
was mixed by sorbitol. Determination of the cellulose enzyme activity performed
by the method of Mandels, while the measurement of protein concentration
performed by the method of Lowry.
The results  showed  that  the  purified enzyme  has  specific  activity 9.18 U/mg,
increased 4.03  times  than the native enzyme. The test of thermal stability of the
enzyme at temperature 50°C for 60 minutes has k
i
= 0.02 min
-1
; t
= 34.65 min
and ?G
i
= 99.7 kJ mol
-1
. The test of thermal stability of the enzyme mixed by
sorbitol 0.5; 1.0; and 1.5 M at temperature 50°C for 60 minutes each has t
= 49.5
min, k
i
= 0.014 min
-1
and ?G
i
= 100. kJ mol
;
t
1/2
= 24.75 min, k
i
= 0.028 min
-1
and ?G
i
-1
= 101.8 kJ mol
-1
; t
= 22.35 min,
ki = 0.031 min
-1
and ?Gi = 100.8 kJ mol
The results showed that the purified enzyme has K
-1
.
m
and V
values
74.02 mg/mL substrate and 6.57
1/2
max
1/2
?mol/mL.min
, and the enzyme mixed by sorbitol
0.5; 1.0; and 1.5 M each has
24.89 mg/mL substrate and 0.92 ?mol/mL.min;
18.39 mg/mL substrate and 0.82 ?mol/mL.min; 14.83 mg/mL substrate and 0.42
?mol/mL.min.
Although the optimum of pH and temperature of the mixed enzyme by sorbitol did
not changed, at pH 7 and at temperature 60
o
C but the thermal stability of
modified enzyme was increased and showed by the decrease in the value of k
i
in accordance with the increase half life and ?G
Key word: Cellulase enzyme, sorbitol, Rhizopus oryzae
i
.
1/2


ABSTRAK


Penelitian ini bertujuan untuk mempelajari pengaruh penambahan sorbitol terhadap
stabilitas enzim selulase dari Rhizopus oryzae. Untuk mencapai tujuan tersebut
dilakukan produksi, isolasi, dan pemurnian enzim. Pemurnian enzim selulase dilakukan
dengan menggunakan fraksinasi dengan ammonium sulfat dan dialisis. Enzim hasil
pemurnian kemudian ditambahkan sorbitol dengan konsentrasi 0,5 M; 1,0 M; dan 1,5 M.
Penentuan aktivitas enzim selulase dilakukan dengan metode Mandels sedangkan
pengukuran kadar protein dilakukan dengan metode Lowry.
Hasil penelitian menunjukkan bahwa enzim hasil pemurnian memiliki aktivitas spesifik
sebesar 9,18 U/mg, meningkat 4,03 kali dibandingkan ekstrak kasar enzim. Uji stabilitas
termal enzim hasil pemurnian pada suhu 50
;t
1/2
= 34,65 menit; dan ?G
i
o
C selama 60 menit memiliki k
= 99,7 kJmol
-1
. Uji stabilitas termal enzim setelah
penambahan sorbitol 0,5; 1,0; dan 1,5 M pada suhu 50
o
C selama 60 menit memiliki
berturut-turut t
1/2
= 49,5 menit, k
i
= 0,014 menit
-1
dan
?G
= 24,75
menit, k
dan
?G
i
i
= 0,028 menit
= 100,8 kJmol
-1
-1
dan
?
G
i
= 101,8 kJmol
-1
;
t
1/2
i
= 100 kJmol
= 22,35 menit, k
.
Enzim hasil pemurnian memiliki nilai Km dan Vmaks berturut-turut sebesar 74,02
mg/mL substrat dan 6,57 ?mol/mL.menit, sedangkan enzim setelah peambahan sorbitol
0,5; 1,0; dan 1,5 M
memiliki nilai Km dan Vmaks berturut-turut sebesar 24,89 mg/mL
substrat dan 0,92 ?mol/mL.menit; 18,39 mg/mL substrat dan 0,82 ?mol/mL.menit;
14,83 mg/mL substrat dan 0,42 ?mol/mL.menit.
Walaupun suhu optimum dan pH optimum enzim setelah penambahan sorbitol tidak
mengalami perubahan, yakni tetap pada pH 7 dan suhu 60
o
C tetapi terjadi peningkatan
stabilitas termal karena adanya penurunan nilai k
?G
i
.
Kata Kunci: Enzim selulase, sorbitol, Rhizopus oryzae.
i
i
= 0,02 menit
-1
; t
1/2
= 0,031 menit
i
serta peningkatan waktu paruh dan
-1
-1
PB  - UNIVERSITAS LAMPUNG
TI  - STUDY THE EFFECT OF ADDITION SORBITOL TOWARD STABILITY
OF CELLULASE ENZYME FROM Rhizopus oryzae
AV  - restricted
ER  -