Judul: dentifikasi Bakteri Penghasil Protease dari Isolat Bakteri Limbah Litter Ayam Broile
Abstrak: Pemanfaatan limbah litter ayam broiler di Indonesia masih terbatas pada pembuatan pupuk, di sisi lain limbah litter ayam broiler dapat juga berfungsi sebagai isolat sumber bakteri penghasil protease. Litter pada dasarnya adalah sekam penuh dengan sisa pakan dan kotoran ayam, sehingga menjadi bahan yang sesuai untuk mikroorganisme tumbuh. Protease adalah enzim pendegradasi protein yang serbaguna dalam penggunaannya di industri dan karenanya menarik banyak minat peneliti untuk mempelajari enzim tersebut. Penelitian ini bertujuan untuk mengkarakterisasi isolat bakteri penghasil protease dari limbah litter ayam broiler. Litter yang digunakan adalah litter yang dikoleksi dari closed house, kandang blok C, Fakultas Peternakan, Institut Pertanian Bogor setelah masa panen. Penapisan bakteri penghasil protease dilakukan dengan menggunakan medium cawan agar yang mengandung susu kasein. Bakteri yang menunjukkan zona bening (halozone) terluas selama penapisan kemudian dimurnikan dan dilakukan analisis morfologis menggunakan pewarnaan Gram. Hasil penelitian menunjukkan bahwa bakteri tersebut termasuk kelompok Gram positif dengan bentuk batang. Urutan 16S rRNA menunjukkan bahwa bakteri memiliki jarak terdekat dengan Bacillus safensis FO-36b dan karena itu ditentukan sebagai B. safensis LA1.
Keyword: 16S rRNA, bakteri, protease, litter broiler

Judul: Karakterisasi Aktivitas Enzim Protease dari Bakteri Limbah Litter Ayam Broiler
Abstrak: Protease merupakan enzim yang paling banyak dikembangkan untuk keperluan industri dan dihasilkan oleh semua organisme. Bakteri penghasil protease bisa didapatkan dari berbagai sumber, diantaranya adalah limbah peternakan. Limbah litter ayam diduga kaya dengan bakteri karena secara alami litter merupakan campuran bahan organik dan ekskreta ayam. Isolat bakteri penghasil protease berbentuk batang (disebut dengan BLA) telah berhasil diisolasi dari litter ayam broiler Kandang C, Fakultas Peternakan, Institut Pertanian Bogor. Penelitian ini bertujuan untuk mengkarakterisasi masa optimum produksi dan kestabilan enzim protease yang dihasilkan dari BLA dari cekaman pH dan suhu. Hasil penelitian menunjukkan bahwa fase stasioner BLA merupakan fase optimum produksi protease sebagaimana diindikasikan dengan pembentukan zona bening yang paling luas dibandingkan dengan yang lainnya. Total konsentrasi protein yang dihasilkan pada fase tersebut adalah 3.95+0.01 mg mL-1. Pengukuran aktivitas enzim pada pH dan suhu yang berbeda mengindikasikan bahwa enzim protease BLA: (1) merupakan protease basa karena aktivitas optimumnya pada pH 10 dengan aktivitas spesifik sebesar 0.16+0.01 U mL-1; dan (2) merupakan protease transisi mesofilik-termofilik karena memiliki aktivitas tertinggi pada suhu 60 oC (0.38+0.06 U mL-1).
Keyword: aktivitas protease, bakteri penghasil protease, limbah peternakan, litter ayam, protease

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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