Judul: Produksi masal inokulum azotobacter, azospirillum dan bakteri pelarut fosfat dengan menggunakan media alternatif
Abstrak: Azospirillum, Azotobacter dan bakteri pelarut fosfat adalah jenis mikroba yang paling umum digunakan dalam pupuk hayati. Untuk mendapatkan inokulan pupuk hayati yang baik, tingginya jumlah sel inokulan, bahan pembawa yang baik serta metode sterilisasi merupakan faktor paling penting dalam menentukan kualitas pupuk hayati. Terkait jumlah sel inokulan dalam bahan pembawa, media tumbuh yang digunakan untuk menumbuhkan sel-sel mikroba memainkan peran yang sangat penting. Untuk produksi massa sel mikroba, media harus mampu mendukung pertumbuhan mikroba yang cepat dengan jumlah sel yang tinggi dengan harga yang murah. Penelitian ini bertujuan untuk mencari media tumbuh mikroba yang mampu mendukung pertumbuhan mikroba yang cepat dengan jumlah sel yang tinggi, media mudah didapatkan dan harganya murah. Penelitian dilakukan di Laboratorium Bioteknologi Tanah, dan Kimia dan Kesuburan Tanah Laboratorium, Departemen Ilmu Tanah dan Sumberdaya Lahan, Fakultas Pertanian, Institut Pertanian Bogor. Hasil penelitian menunjukkan bahwa media IPB RI-1 dapat menghasilkan 1010 cfu/ml Azotobacter, 108 cfu/ml Azospirillum dan 109 cfu/ml Bakteri Pelarut Fosfat. Media Nutrient Broth hanya mampu menghasilkan jumlah mikrob sebanyak 108 cfu/ml media. Ini berarti bahwa media IPB RI-1 mampu meningkatkan populasi Azotobacter 100 kali lipat dan Bakteri Pelarut Fosfat meningkat 10 kali lipat dari populasi mereka di dalam media Nutrient Broth. Media IPB RI-2 mampu meningkatkan populasi Azotobacter 10 kali lipat dibandingkan dengan media Nutrient Broth. Biaya bahan media IPB RI-1 dan IPB RI-2 sangat murah dibandingkan dengan biaya bahan media Nutrient Broth. Biaya bahan media IPB RI-1 hanya 3% ( Rp. 945) dan IPB RI-2 sekitar 2 % (Rp. 690) dari biaya media Nutrient Broth ( Rp.27.752).
Keyword: 

Judul: Produksi Masal Inokulum Azotobacter, Azospirillum dan Bakteri Pelarut Fosfat dengan Menggunakan Media Alternatif
Abstrak: Azotobacter, Azospirillum and phosphate solubilizing bacteria are the most commonest microbial inoculant used in preparation of biofertilizer. To have good biofertilizers inoculant, the high number of inoculant cells, and good carriers as well as the method of carriers sterilization are among the most important factors determined the quality of biofertilizer. Related to the number of inoculant cells in carriers, the growing medium used to cultivate the microbial cells plays very important role. For mass production of microbial cells of inoculant, the medium should be able to support fast growth with high number of microbial cells of inoculant but the price of medium should be reasonably cheap. This study aimed to find cheap growing medium that can support high number of microbial inoculant cells and the components of the medium should be easy to obtain and the price is cheap. The study was conducted at the Laboratory of Soil Biotechnology, and the Laboratory of Soil Chemistry and Soil Fertility, the Department of Soil Science and Land Resources, Faculty of Agriculture, Bogor Agricultural University (IPB). The results showed that the media IPB RI-1 was able to support the growth of 1010 cfu / ml Azotobacter, 108 cfu / ml Azospirillum and 109 cfu / ml Phospate Solubilizing Bacterium. The Nutrient Broth media was only able to produce microbial cells much as 108 cfu / ml media. This means that the media IPB RI-1 increased 100-fold population of Azotobacter compared to the growth of this bacterium in Nutrient Broth and Phospate Solubilizing Bacteria increased 10-fold of their population in Nutrient Broth medium. The costs of the IPB RI-1 and IPB RI-2 were much cheaper compared to the cost of Nutrient Broth media. The cost of media IPB RI-1 only 3% (Rp 945) and IPB RI-2 about 2% (Rp 690) of the cost of media Nutrient Broth (Rp 27.752).
Keyword: 

Judul: Truncated Stop Loss as a Optimal Solution of Reinsurance Agreement in One-Period Model
Abstrak: Reinsurance is one of risk management efforts of an insurance company, which is called the cedent. Similar with insurance, reinsurance constitutes the cedent to pay the premium. We consider one-period reinsurance model and derive a rule which minimizes the ruin probability of the cedent for a fixed reinsurance premium. Therefore, it is needed to construct an optimal reinsurance agreement for the cedent. The premium is calculated according to four different principles, i.e. economic, generalized zero-utility, Esscher, and mean-variance principles. Stop loss is a reinsurance contract which protect the insurance company for losses that exceed a certain amount. The result of this research shows that a truncated stop loss is an optimal agreement in the class of all reinsurance contracts with various premiums calculated using above mentioned principles.
Keyword: