Judul: Isolasi Dan Identifikasi Bakteri Kitinolitik Sebagai Agens Biokontrol Cendawan Patogen Pada Kokon Cricula Trifenestrata (Lepidoptera: Saturnidae).
Abstrak: Cricula trifenestrata merupakan salah satu serangga penghasil sutra alam yang belum didomestikasi, sehingga dikenal sebagai ulat sutra liar. C. trifenestrata mengeluarkan air liur yang mengandung protein dan menjadi bahan pembentukan kokon. Kokon ini dikumpulkan untuk diolah menjadi benang sutra. Sutra hasil olahan kokon C. trifenestrata memiliki nilai ekonomi yang tinggi di pasaran karena memiliki serat berwarna kuning emas yang merupakan warna khas kokonnya. Hal inilah yang menjadi pembeda antara C. trifenestrata dengan ulat sutra lainnya. Salah satu patogen yang dikenal menyerang kokon ulat sutra ialah cendawan. Serangan cendawan dapat mengakibatkan kualitas dan kuantitas benang sutra yang dihasilkan mengalami penurunan. Di India, kegagalan panen kokon akibat serangan cendawan mencapai 30-40%. Cendawan memiliki dinding sel yang tersusun atas kompleks kitin dan merupakan target utama bagi agens anti cendawan, misalnya fungisida kimiawi. Namun, adanya dampak negatif yang ditimbulkan dari penggunaan fungisida kimiawi menyebabkan perlu dicari fungisida biologi seperti memanfaatkan bakteri kitinolitik potensial yang mampu menghambat bahkan membunuh cendawan patogen karena menghasilkan enzim kitinase. Bakteri kitinolitik memiliki potensi tinggi sebagai agens pengendali biologi terhadap cendawan patogen pada C. trifenestrata sehingga penurunan kualitas dan kuantitas sutra emas dapat dihindari. Tujuan penelitian ini ialah untuk mengisolasi bakteri kitinolitik dan cendawan patogen asal kokon C. trifenestrata serta identifikasi dan potensinya sebagai biokontrol. Hasil isolasi dari kokon C. trifenestrata di Desa Babakan Lebak, Dramaga, Bogor didapatkan 10 isolat cendawan dan 36 isolat bakteri kitinolitik dengan Indeks Kitinolitik (IK) bervariasi. Isolat bakteri kitinolitik BSEP.3 diketahui mampu menghambat isolat cendawan CSAJ.2 yang diduga sebagai cendawan patogen dengan persentase penghambatan sebesar 50%. Kitinase yang dihasilkannya sebesar 5.11 U/mL pada jam ke-15 waktu inkubasi. Ekstrak kasar kitinasenya memiliki persentase penghambatan sebesar 47.5%. Sekuen hasil amplifikasi gen penyandi 16S rRNA dan konstruksi pohon filogenetik menunjukkan bahwa bakteri BSEP.3 memiliki kemiripan 98% dengan Bacillus amyloliquefaciens galur B5. Sekuen hasil amplifikasi daerah ITS rDNA dan konstruksi pohon filogenetik menunjukkan bahwa isolat cendawan CSAJ.2 memiliki kemiripan 100% dengan Trichoderma virens galur TV242. Aplikasi kitinase ekstrak kasar isolat bakteri kitinolitik BSEP.3 menunjukkan kemampuannya dalam menghambat pertumbuhan cendawan patogen pada kokon ulat sutra emas C. trifenestrata baik secera preventif maupun kuratif.
Keyword: Bacillus amyloliquefaciens, Trichoderma virens, kitinase

Judul: Isolasi dan Identifikasi Bakteri Kitinolitik Penghambat Pertumbuhan Cendawan Patogen Asal Kokon Cricula trifenestrata
Abstrak: Gold Silkworm’s cocoon is a coat of Cricula trifenestrata’s pupa that include part of life cycle. The fiber which is resulted from processing cocoon has high economic value because the specific of gold colour that doesn’t have any else cocoon. However, on the process often occurred many problems that could decrease quantity and quality of cocoon, such as attack from pathogenic fungi. For controlling of the pathogenic fungi has been used chemical agent, but using regularly caused some negative effects. As alternative using chitinolytic bacteria as biocontrol, because of chitin is the highest component of the fungi cell wall. Therefore the objectives of this research were to isolate and identify of chitinolytic bacteria that inhibited fungi pathogen which isolated from cocoon of C. trifenestrata. 17 strains chitinolytic bacteria were isolated from two samples cocoon of health pupa and sick pupa. There were four isolates CH2, CH10, CS1, and CS4 had highest value of chitinolytic index. CH10 and CS1 strains showed highest chitinase activity, both isolates were identified using MicrogenTM GenA+B ID System and categorized as Shewanella putrefaciens. Scopulariopsis sp. and FC (unidentified) were isolated from cocoon of sick pupa. Strain CH10 inhibited FC on culture bacteria test but not from its in chitinase. Scopulariosis sp. had been inhibited by culture and its chitinase.
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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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