Judul: Isolasi dan karakterisasi protease bacillus pimilus isolat Y3
Abstrak: Penelitian ini bertujuan untuk mempelajari aspek pemurnian dan karakterisasi enzim protease ekstraseluler dari Bacillas paniks. Bakteri yang dipergunakan dalam penelitian ini adalah Bacilks pantilor isolat Y, yang disolasi dari linahir tahu dan telah diidentifikasi oleh Likumahwa (1993) di Pusat Antar Universitas Bioteknologi, Institut Pertanian Bogor. Media dan cara yang dipergunakan untuk memproduksi enzim didasarkan pada hasil penelitian Dwiastuti (1993). Media yang dipergunakan berupa limbah cair tahu ditambah dengan glukosa sebanyak 1% (b/v) dengan pH awal 7.0. Fermentasi untuk produksi dikkalan pada suhu 37°C, 200mm selama 15 jam Protease Bacillus pumilus isolat Y, menunjukkan aktivitas maksimum peda suhu optimum sebesar 50°C. Sedangkan aktivias maksimumnya dicapai pada pH optimum sebesar 8.0 dan cenderung memperlihatkan kestabilan pada pH sekitar merupakan protease semi alkalis ..dst
Keyword: Bacillus pumilus isolat Y3, Enzymes

Judul: Pemurnian dan karakterisasi protease dari Bacillus punilus
Abstrak: Penelitian ini bertujuan mempelajari sifat-sifat enzim protease ekstraselular dari Bacillus pumilus yang diisolasi dari limbah cair tahu di Indonesia. Galur murni yang digunakan Bacillus pumilus Y1 merupakan hasil isolasi dari Likumahua Yosi T. Maria (1993). Karakteristik enzim protease yang diamati meliputi pengaruh suhu, pH, jenis dan konsentrasi ion logam terhadap aktivitas enzim, param- eter kinetika reaksi ( Km dan Vmax ), dugaan berat molekul, dan tingkat kemurnian yang dapat dicapai setelah pemurnian melalui pengendapan garam, dialisis dan kromatografi. Produksi enzim dilakukan dengan proses fermentasi sistem curah ( batch). Limbah cair tahu sebanyak 800 ml (pH 7), ditambah 5% susu skim digunakan sebagai medium. untuk pertumbuhan Bacillus pumilus. selam 12 jam Fermentasi dilakukan dalam bejana fermentor pada suhu 37° C, dengan agitasi 100 rpm, dengan aerasi 1 VVM dan pH 7. Pemanenan enzim protease dilakukan dengan sentrifugasi pada 2000 rpm selama 20 menit pada suhu 0° C. Supernatan yang dihasilkan disebut ekstrak kasar…dst
Keyword: Protease, Bacillus punilus, Microbial enzym, Permentation

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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