Judul: Produksi dan Karakterisasi Enzim Tanin Asil Hidrolase dari Aspergillus niger.
Abstrak: Tannin acyl hydrolase (tannase) is a hydrolytic enzyme that acts on tannins. The application of tannase is mostly in food and medical industries. This research is aimed to produce and characterize tannase from Aspergillus niger isolated from pod cacao. The first step of this research includes determination of optimal pH, temperature and incubation period to produce tannase. Optimal tannase production was obtained at pH 5.5, 28 oC and incubation period of 3 days. Afterthat, production media optimization was conducted. The tested media were solid and liquid media with inducer concentration varied at 0, 3, 5 and 7%. The best media obtained was the solid media with tannic acid concentration as inducer of 5%. The next step was tannase fractionation by ammonium sulphate which was followed by dialysis process. The saturation le vel of ammonium sulphate used was 30-80% where the best activity obtained was at the saturation level of 60%. Compared to that of crude enzyme, specific activity of tannase after dialysis was four folds. Characterization results showed that optimum activity was at 35-50 oC and pH 6. Tannase was activated by K+ and Na+ with concentration of 10 and 50 mM, while Mg2+ ion could activate only at 10 mM. The addition metal ions like Zn2+, Cu2+, Ca2+, Mn2+ and Fe2+ inhibited the enzyme activity. From test of variation of substrate, it was found that the Km value of tannic acid and gallotannin was 0.401 and 6.611 mM respectively. While the Vmax value of tannic acid was 10.804 U/ml and gallotannin was 12.406 U/ml. Based on the Michaelis- Menten constant (Km), tannase of obtained in this research was more active in hydrolysing depsid bonds rather than ester bonds.
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Judul: Pemanfaatan Limbah Padat Kacang Hijau Untuk Produksi Enzim- Emilase, Amiloglukosidase Dan Selulase Dari Aspergillus niger Dan Aspergillus oryzae
Abstrak: Penelitian ini bertujuan untuk mempelajari pemanfaatan limbah padat kacang hijau sebagai media fermentasi untuk menghasilkan enzim damilase, amiloglukosidase dan selulase dari Aspergillus niger dan Aspergillus oryzae. A. niger L-51 dan A. oryzae L-54 masing-masing ditum- buhkan pada media limbah padat kacang hijau yang ditambah dengan air suling, atau larutan mineral yang mengandung NaH2PO4, CaCl2, KCl, dan MgCl2 dengan konsentrasi masing- masing sebesar 4.7, 0.1, 0.02, dan 0.02 persen. Jenis fer- mentasi yang digunakan adalah fermentasi media padat dan media cair. Setelah waktu inkubasi yang ditetapkan selama dua, lima, dan sembilan hari dicapai, enzim yang dihasilkan dipanen dan diuji aktifitasnya. Juga dilakukan pengukuran pH dan kadar protein terlarut di dalam filtrat enzim. Secara umum fermentasi media cair menghasilkan aktifitas enzim d-amilase, amiloglukosidase dan selulase yang lebih baik, kecuali untuk amiloglukosidase dari A. oryzae L-54 fermentasi media padat menghasilkan aktifitas enzim yang lebih baik. Semakin lama waktu inkubasi, aktifitas enzim d-amilase yang dihasilkan semakin rendah, sedangkan aktifitas enzim amiloglukosidase menunjukkan peningkatan sampai hari kelima kemudian menurun kembali, sebaliknya aktifitas enzim selu- lase menurun sampai hari kelima kemudian meningkat kembali. A. niger L-51 menghasilkan aktifitas enzim d-amilase tertinggi sebesar 5.203 unit/ml filtrat enzim atau 7.310 unit/mg protein pada fermentasi media cair dengan penambah- an air suling dan waktu inkubasi dua hari. Dengan waktu inkubasi yang sama diperoleh aktifitas enzim d-amilase ter- tinggi dari A. oryzae L-54 sebesar 4.877 unit/ml filtrat enzim 5.022 unit/mg protein pada fermentasi media cair de- ngan penambahan larutan mineral…dst
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Judul: Implementation of Spatio-Temporal Change Query in Relational Database.
Abstrak: Geographic object changes in various views. Object changes are recorded using a model of static storage. No historical connection between old version data and new version data has been built. For that, a storage model of spatio-temporal queries that can analyze spatio-temporal changes has been developed. The object changes the geometry are grouped according to the taxonomy of Spatio-Temporal Pattern Change. This research has been able to apply the query patterns change including born, expand, merge, contract, split, normal and die. This query based on geometric (area) changes. The implementation of spatio-temporal change queries represents an object changes continuously with easy, change detection is done by comparing two versions of data. Keyword: spatio-temporal change query, spatio-temporal change pattern.
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