Judul: Identifikasi dan Karakterisasi Bakteri Rumen yang Memiliki Aktivitas Enzim Selulase
Abstrak: Bakteri rumen memiliki banyak potensi untuk dikembangkan sebagai probiotik dan sumber enzim. Tujuan penelitian ini adalah memperoleh isolat bakteri yang memiliki enzim selulase dengan aktivitas selulolitik tinggi. Isolat bakteri diisolasi menggunakan metode hungate pada rumen sapi PO Bioteknologi LIPI Cibinong. Hasil identifikasi berdasarkan sekuen gen 16S rRNA menunjukkan bahwa isolat yang memiliki aktivitas selulolitik tertinggi dengan indeks selulolitik 3.39 adalah Lactobacillus sp. Perlakuan pada pengujian karakter aktivitas enzim ialah suhu 40, 50, 60 0C dan pH 5, 6, 7, 8. Hasil uji aktivitas enzim menunjukan bahwa suhu dan pH optimum aktivitas enzim kasar pada supernatan adalah 50 oC dan pH 8 dengan aktivitas masing-masing sebesar 0.0233 U/ml dan 0.0290 U/ml.
Keyword: Lactobacillus, suhu optimum, pH optimum, 16S rRNA, metode hungate

Judul: Seleksi Isolat Bakteri Rumen (Anaerob) Penghasil Karboksi Metil Selulase
Abstrak: Ternak ruminansia mempunyai kelebihan. yaitu mampu memanfaatkan hijauan sebagai swnber makanannya. Ruminansia mampu memakan bahan yang kaya akan serat kasar menjadi produk yang dapal diabsorpsi oleh darah. Kemampuan ini berkaitan dengan adanya mikroorganisme yang ada dalam rwnell. Upaya untuk mengoptimasikan peranan mikroorganisme rumen sebagai penghasil selulase untuk mencema serat ltijauan, menjadi menarik untuk dipelajari. Dengan bantuan ennrn yang dihasilkan oleh mikroorganisme ini, produktivitas ternak dapat ditingkatkan karena penambahan enzim ini akan memudahkan temak dalam mencema hijauan. Pada penelitian ini, dilakukan seleksi untuk menentukan isolat bakteri rumen yang menghasilkan selulase dengan aktivitas yang tinggi. Isolat bakteri rumen anaerob yang beljumlah 21 buah dipindahkan ke medium cair yang mengandung selobiosa 0,5 % Inokulum laiu dipindahkan ke medium M8 cair yang ditambah substrat (rumput gajah. jerami padi, dan kertas saring). Aktivitas selulase diuji dengan menentukan kadar gula pereduksi dengan menggu.nakan asam dinitrosalisilat. yang diukur absorbansnya pada A. 560 nm dengan substIat karboksi metil selulosa(CMC). Dari basil penelitian dapat disimpulkan bahwa dari 21 isolat bakteri rwnen anaerob, terdapat beberapa isolat yang mempunyai aktivitas CMC-ase pada tiga medium yang berbeda. Isolat nomor I mcnunjukkan aktivitas CMC-ase tertinggi pada. substrat rumput gajah dengan akti\"itas 0,0122 unit/mi. lsolat nomor 11 dengan aktivitas 0,0204 unit/mI menunjukkan aktivitas tertinggi pada substrat jerami padi. Substrat kertas saring
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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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