Judul: Aktivitas Selulolitik beberapa Kapang
Abstrak: Cellulose is the main component of cell wall of plants and it is the most abundant biopolymer on earth. Generally, cellulose is degraded by microorganisms-producing cellulase. The enzyme consists of endoglucanase, exoglucanase, and cellobiase. The aim of this research was to study the cellulolytic’s ability of some molds. Fourty two fungal isolates were first examined of their cellulolytic’s ability on CMC agar. T. reesei QM6a was used as comparison strain. Certain isolate of Aspergillus niger, Aspergillus ornatus, and Paecilomyces sp. have cellulolytic index that were higher than those of other isolates. The optimum activity for CMC-ase of A. niger and A. ornatus occurred on 3 days incubation, while those of Paecilomyces sp. and T. reesei QM6a was 5 days and 2 days incubation, respectively. Of those species, A ornatus showed the highest activity of CMC-ase (0.550 nkat/ml), avisel-ase (0.077 nkat/ml), and FP-ase (0.255 nkat/ml). The optimum temperature for CMC-ase activity of A. ornatus was 30 0C, while the optimum acidity was 7.
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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: Pemodelan Nilai Tukar Rupiah Terhadap US Dollar Menggunakan Deret  Waktu Hidden Markov Dua Waktu Sebelumnya
Abstrak: Nilai tukar Rupiah terhadap US Dollar mengalami perubahan setiap waktunya dalam periode yang panjang dan perubahan yang terjadi mungkin terjadi kembali di masa mendatang. Jika penyebab kejadiannya tidak diamati secara langsung dan membentuk suatu rantai Markov maka perubahan nilai tukar Rupiah dapat dimodelkan dengan model deret waktu hidden Markov. Untuk menggambarkan perilaku nilai tukar Rupiah terhadap US Dollar, dalam karya ilmiah ini digunakan model deret waktu hidden Markov dua waktu sebelumnya. Model ini mengasumsikan bahwa nilai tukar Rupiah terhadap US Dollar bergantung pada rantai Markov yang merupakan penyebab kejadian yang tidak diamati dan nilai tukar Rupiah dua waktu sebelumnya.
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