Judul: Development of Pectinase Enzyme production from Actinomycetes for Pectiologosaccharide production
Abstrak: Indonesia mempunyai megabiodiversitas mikroba yang luar biasa baik dari mikroba darat maupun mikroba laut yang potensial untuk digunakan sebagai sumber enzim baru termasuk pektinase. Aktinomisetes diketahui mempunyai potensi sebagai penghasil berbagai senyawa bioaktif dan penghasil enzim untuk aplikasi di berbagai industri termasuk industri pangan. Oleh karena itu perlu dilakukan penapisan terhadap koleksi isolat Aktinomisetes laut koleksi InaCC untuk mendapatkan kandidat isolat unggul penghasil pektinase yang mempunyai kemampuan menghidrolisis pektin untuk produksi pektioligosakarida (POS). Penapisan aktinomisetes darat dan identifikasi secara molekuler 16S rRNA yang dilakukan pada penelitian sebelumnya menunjukkan bahwa aktinomisetes darat penghasil pektinase teridentifikasi sebagai Kitasatospora sp. Penelitian ini difokuskan untuk melakukan penapisan aktinomisetes laut penghasil enzim pektinase serta melakukan penelitian lanjutan yaitu proses produksi, purifikasi, karakterisasi, dan analisis potensinya untuk produksi POS dari substrat pektin. Penapisan dilakukan dengan menggunakan metode Double Layer Agar (DLA), kemudian dilakukan tahapan purifikasi enzim pektinase menggunakan kolom kromatografi penukar anion, dilanjutkan dengan uji karakterisasi serta hidrolisis substrat pektin untuk produksi pektioligosakarida serta analisis produk hidrolisis dengan TLC. Hasil penapisan diperoleh satu isolat unggul penghasil pektinase dengan diameter zona bening sekitar 3,7 cm pada larutan pH 7,0 yaitu isolat BLH 1-20. Hasil identifikasi secara molekular dengan sekuen 16S rRNA menggunakan BLAST menunjukkan bahwa isolat BLH 1-20 tersebut adalah Streptomyces sampsonii. Hasil karakteriasai uji pH diperoleh nilai aktivitas 5,141 U/mL pada pH .6.0, sedangkan pada uji suhu diperoleh suhu optimum pektinase pada suhu 30 °C dengan aktivitas sebesar 5,395 U/mL. Hasil pemurnian enzim pektinase dari Kitasatospora sp. dengan metode anion exchange menggunakan kolom kromatografi 5 mL QFF secara parsial menunjukkan kromatogram dengan satu puncak utama pada aktivitas enzim pektinase maupun protein enzim dengan nilai aktivitas berturut-turut sebesar 0,089 U/mL dan 1,096 mg/mL. Karakterisasi enzim dengan uji pH dan suhu menunjukkan pH optimum pektinase terdapat pada larutan fosfat pH 8,0 dengan nilai aktivitas sebesar 0,271806 U/mL, suhu optimum diperoleh pada suhu 40 °C dengan aktivitas sebesar 0,294 U/mL, dan stabilitas pektinase dicapai pada suhu 40 °C dengan waktu inkubasi 30 menit sebesar 0,275 U/mL. Hasil analisis TLC menunjukkan pektioligosakarida yang terbentuk dari hasil hidrolisis pektinase Kitasatospora sp. terjadi pada jam ke 24 – 96
Keyword: aktinomisetes, hidrolisis, karakterisasi, pektinase, purifikasi

Judul: Production and Immobilization of Pectinase from Bacillus sp. 2P11 Using Alginate Beads
Abstrak: Enzymes are biocatalysts with high catalytic power that have the potential to be used in the industrial field. Pectinase is an enzyme that degrades plant cell walls and is commonly used in the food industry to accelerate the extraction of fruit juices. Microbes are a source of enzymes that are often used because they grow on various media and can easily be increased by adjusting the growth conditions. Immobilization is the stage of developing a sustainable bioprocess by reusing enzymes bound to a matrix. Therefore, this study aimed to immobilize the pectinase enzyme and the efficiency of repeated use of the immobilized pectinase. This research begins with the rejuvenation of Bacillus sp. 2P11, which has been isolated from previous studies. The cocoa husk contains pectin, which can be used as a substrate to produce pectinase. Pectinase production was carried out by growing Bacillus sp. 2P11 on liquid production media with a cocoa liquid substrate with variations (1-15%) was tested for enzyme activity. Crude extract enzyme activity was obtained by optimizing microbial growth on the media by making an enzyme production curve. The enzyme production curve makes with an incubation time of 96 hours and observations every 12 hours. Enzyme activity was measured using Dinitrosalicylic Acid (DNS) reagent with a standard solution of galacturonic acid. Precipitation was carried out with ammonium sulfate salt and then dialyzed. The enzyme was precipitated gradually from 0% to the ammonium sulfate saturation level of 80%. Dialysis was carried out by inserting a cellophane tube containing the enzyme into a 0,05 M pH 5 acetate buffer. The purified pectinase was then immobilized by trapping using sodium alginate and CaCl2. Immobilized pectinase stored for 14 days was measured for its enzyme activity repeatedly. The activity of the crude extract of the pectinase enzyme obtained was 0,41 U/mL. Precipitation with ammonium sulfate and dialysis increased pectinase activity by 0,45 U/mL and 0,58 U/mL, respectively. Enzymes can be used repeatedly with enzyme immobilization. In this study, the immobilization of the enzyme entrapment method with sodium alginate and CaCl2 was designed with the response surface method. The optimum concentration of sodium alginate was 0,5%, and CaCl2 0,3 M, with the percentage of an immobilized enzyme was 40,7%, and pectinase activity was 0,23 U/mL. Stability and repeated use of immobilized pectinase can be done up to 5 times., Enzim adalah biokatalis dengan daya katalik tinggi yang memiliki potensi untuk digunakan pada bidang industri. Pektinase merupakan enzim pendegradasi dinding sel tanaman yang umum digunakan untuk industri pangan seperti mempercepat ekstraksi sari buah. Mikroba merupakan sumber penghasil enzim yang sering digunakan karena tumbuh pada berbagai media dan mudah ditingkatkan hasilnya dengan mengatur kondisi pertumbuhan. Imobilisasi merupakan tahapan pengembangan bioproses berkelanjutan dengan menggunakan kembali enzim yang terikat pada suatu matriks. Oleh karena itu, tujuan penelitian ini yaitu melakukan imobilisasi enzim pektinase dan mengukur efisiensi penggunaan berulang pektinase imobil tersebut. Penelitian ini diawali dengan peremajaan isolat Bacillus sp. 2P11 yang telah diisolasi dari penelitian terdahulu. Kulit kakao mengandung pektin sehingga dapat digunakan sebagai substrat untuk menghasilkan pektinase. Produksi pektinase dilakukan dengan menumbuhkan Bacillus sp. 2P11 pada media
Keyword: Alginate beads, Bacillus sp. 2P11, cacao, pectinase, immobilization

Judul: The Effects of Variance of Interest rate to Variance of Annuity Future Values
Abstrak: Time value of money is a concept that refers to the difference of the value of money due to time difference. The value of money for present time would not be the same as the value of money in the future. The value of money for present time is called as Present Value (PV) of the money and the value of money for future time is called Future Value (FV) of the money. Determination the value of money, for present and future time, depends on the time and rate of return. The value of money is determined by several factors such as inflation, fluctuation of interest rates, and government policy in securities and taxation. Due to fluctuation of the value of money we need a FV formulation, it is useful for knowing whether an investment can be profitable or not, and this information is useful also in budget analysis. Annuity is defined as a series of payments made for a specific period. The payment, fixed or varied, can be made at the beginning or at the end of the period. Annuity paid at the beginning of the period is called annuity-due and annuity paid at the end of the period is called immediate annuity-certain. The accumulated value of the annuity after few years later is called as a final value or a future value. Burnecki et al. (2003) have discussed about the FV of a fixed-rate annuity in which payments are made according to the arithmetic or geometric series. They have also examined FV for annuities in which payments are made according to arithmetic or geometric series with random rates of interest. This paper examines FV for annuity-due in which payments are made according to arithmetic or geometric series with interest rates as a random variable, which is normal distribution ,  . Future value formula is expressed in recursive form. FV for annuity-due which payments are made according to the arithmetic or geometric series with random rates of interest is calculated by theoretical way and simulation way. The random rates of interest is denoted as k k i  i  , where k i an independent random variable; i is a constant and k  is a random variable which has normal distribution ,  . By using the determined parameters, a sequence of random rates of interest are generated for theoretical calculation. Meanwhile for the simulation, the random rates of interest is generated 1000 times for the simulation. The generated data give mean value, variance, and standard deviation. Moreover, error of mean value, variance, and standard deviation from the theoretical and simulation results are calculated. Error calculation uses Symmetric Mean Absolute Percentage Error (SMAPE). The smaller the value of SMAPE is the more accurate the simulation. The interest rate variances are varied from 0.000036 to 0.0001 to study the relationship between variance of rates of interest and variance of future value. The theoretical and simulation results show that when the variance of random rates of interest increases, then the variance of FV increases linearly. FV of the annuity-due in
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