Judul: Karakter Selulase Bakteri Isolat 26 Asal Tanah Hutan Taman Nasional Bukit Duabelas, Jambi, Indonesia
Abstrak: Indonesia is a country that has developed rapidly in the agricultural sector, which generated agricultural waste and it can be degraded into more useful materials by using microorganisms, such as bacteria. Isolate 26 origins from Bukit Duabelas National Park, Jambi alleged to have cellulase which is able to degrade cellulose into simple molecules. This study aimed to characterize isolate 26 which included the optimum of pH and temperature, for enzime activity as well as the appropriate substrates. Determination of cellulase enzyme activity of crude extracts performed at the optimum production of cellulase enzymes by modification of Miller (1959) method on the substrate CMC and filter paper, and applied to rice straw, corn cobs and banana peels. Optimum production of crude enzyme extract obtained from the 4th hour incubation period that is equal to 5.25 mU/mL with protein content of 0.102 mg/ mL. Cellulase from isolate 26 had an optimum activity at pH 4.5 and a temperature of 90OC. Compared to other substrates cellulase from bacterial isolate 26 had the highest ability to degrade on the banana peels.
Keyword: Bogor Agricultural University (IPB), cellulase., agricultural waste, characterization, cellulolytic bacteria

Judul: Karakterisasi Enzim Selulase dan Aplikasinya pada Substrat Limbah Pertanian
Abstrak: Cellulose is the most abundant plant cell walls. Lignocellulolytic are consist of cellulose, hemicelluloses and lignin. Degradation of cellulose involves a complex interplay between different cellulolytic enzymes. Among others, it has been widely accepted that three types of cellulases including endoglucanases, exoglucanases and β-glucosidases act synergistically to convert cellulose to glucose. This study was aimed to characterized cellulase enzyme which produced by cellulolytic bacteria from soil and applied it on agricultural waste such as rice straw, corn cob and banana peel. Qualitative analysis have done on 9 isolates cellulolytic bacteria to know the highest cellulolytic index by using congo red 0.1%. From 9 isolates, 1 isolate have IS 1.75. Quantitative analysis showed isolate 6-2 has the highest cellulase activity of 0.005U/ml. Highest activity of cellulase enzyme from isolate 6-2 resulted on bufer pH 7 and 40oC. Cellulase activity of isolate 6-2 was stable for 75 minutes. Isolate 6-2 has relatively low cellulase activities in CMC as it has small enzyme activity in degrading substrates of agriculture waste. The cellulose enzyme activity on ricestraw resulted 0.007U/ml, corncob resulted 0.008U/ml, and bananapeel resulted 0.013U/ml. Isolate 6-2, gram positive bacteria can degrade cellulose by using cellulase enzyme. On the application cellulase enzyme activity on bananapeel was higher than the others.
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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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