Judul: Karakterisasi dan Uji Aktivitas Selulotik Kapang Endofit Makroalga (Sargassum sp, Gracilaria sp, Caulerpa sp dan Gelidium sp) di Habitat Lamun Pulau Pari, Kepulauan Seribu
Abstrak: Macroalgae is one source of raw materials for bioethanol which has good potency to be developed as renewable energy. Bioethanol is a fermented product of carbohydrates that requires molds to produce enzym in breaking down complex cellulose into more simple form. The aims of this research were (1) to explore diversity endophytic molds associated with macroalgae living in seagrass habitats of Pari Island, Kepulauan Seribu ; (2) to measure cellulolytic activity of endophytic molds. A total of 21 isolates molds were isolated from four species of macroalgae, namely Sargassum sp, Gracilaria sp, Caulerpa sp, and Gelidium sp. Molds were isolated using CMC (Carboxy Methyl Cellulose) media, stained using red congo, and enzymatic activities were measured according to Milles method. The highest value of cellulolytic index was observed for Aspergillus westerdijkial isolated from Caulerpa sp (PCLAR 6). Cellulolytic activity of Aspergillus versicolor and Aspergillus sydowii showed optimum performance on day-2, Penicillium citrinum and Aspergillus westerdijkial was on day-1. Cellulolytic enzym showed optimum activity under pH phosphate 7 and temperature of 40 0C.
Keyword: macroalgae, cellulolytic activity, cellulase enzym, molds

Judul: Eksplorasi Bakteri Laut Untuk Uji Aktivitas Agarolitik Dari Makroalga Gracilaria Salicornia Sebagai Bahan Baku Bioetanol
Abstrak: Gracilaria salicornia memiliki kandungan agar yang tinggi dan dapat dijadikan bahan baku bioetanol. Salah satu proses produksi bioetanol adalah hidrolisis enzim. Bakteri yang mendegradasi dinding sel makroalga dan menghasilkan enzim agarase disebut bakteri agarolitik. Tujuan dari penelitian ini adalah (1) untuk mendapatkan isolat bakteri dari makroalga Gracilaria salicornia yang memiliki aktivitas enzim agarase tertinggi dan (2) memperoleh karakteristik enzim agarase yang dihasilkan untuk produksi bioetanol. Hasil isolasi bakteri dari makroalga Gracilaria salicornia didapatkan dua isolat bakteri terbaik, yaitu isolat dengan kode N1 dan N3. Indeks agarolitik yang terbentuk dari isolat N1 adalah 2.27 mm dan 2.32 mm untuk isolat N3. Waktu terbaik untuk penuangan inokulum ke media produksi yang didapat dari kurva pertumbuhan kedua isolat adalah jam ke-13. Aktivitas enzim agarase tertinggi dihasilkan oleh isolat N3 yaitu sebesar 2.84 × 10-3 U/mL dan isolat N1 sebesar 2.34 × 10-3 U/mL pada waktu inkubasi yang sama yaitu jam ke-18. Aktivitas enzim agarase isolat N1 dan N3 optimum pada pH 7 dan suhu 30 °C.
Keyword: agarase, bakteri, enzim, Gracilaria salicornia, makroalga

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.
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