Judul: Isolasi dan Identifikasi Bakteri Termofilik Penghasil Selulase dari Kelapa Sawit (Elaeis guineensis)
Abstrak: Cellulase is an enzyme catalyzing hydrolysis of cellulose which usually consists of endoglucanases (EC.3.2.1.4), exoglucanases (EC.3.2.1.91) and β-glucosidases (EC.3.2.1.21). Cellulase is a very important enzyme due to its numerous industrial applications. The aim of this research were to isolate and identify cellulase-producing thermophilic bacteria that can be used to increase value added in oil palm industries. Samples of soil, empty fruit bunch compost and palm kernel meal were collected from oil palm plantation for obtained thermophilic bacteria. The samples were screened of cellulase-producing thermophilic bacteria by using a Congo Red method were made on carboxymethyl cellulose (CMC) agar plates. The bacterial cultures were incubated in a shaking incubator (140 rpm) at 50oC for 24 hours. The assay for the enzymatic activity was based on the release of glucose that was detected using 3,5-dinitrosalicylic acid (DNS). In this research, 19 isolates of bacteria were isolated. It was found that 11 isolates of bacteria showed positive results with clear zone around the cultures by using Congo Red method. The result showed that isolates for CK1, EM4 and CK3 possesed the highest enzyme activity of 13.56, 12.50 and 10.49 U mL-1 for cellulase was detected at pH 7, respectively. The results of strain identification based on 16S rRNA showed that strain CK1, EM4 and CK3 were identified as Bacillus subtilis.
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Judul: Isolation and Characterization of Cellulolytic  Bacteria from Banana Peel Ecoenzymes
Abstrak: Selulosa merupakan komponen biomassa tumbuhan yang paling melimpah namun tidak mudah larut dalam air karena strukturnya yang kompleks. Penggunaan enzim selulase mampu menjadi kunci dalam degradasi bahan selulosa secara efisien dan efektif. Pemanfaatan ekoenzim dapat dilakukan untuk mengurangi jumlah limbah rumah tangga yang biasanya didominasi oleh limbah organik. Ekoenzim merupakan cairan organik kompleks yang dihasilkan dari proses fermentasi bahan limbah buah segar, gula, dan air dengan perbandingan 3:1:10 setelah tiga bulan masa fermentasi. Penelitian ini bertujuan mengisolasi dan melakukan karakterisasi bakteri selulolitik yang berasal dari ekoenzim hasil fermentasi kulit buah pisang. Sembilan bakteri selulolitik berhasil diisolasi dan ditumbuhkan pada media CMC (Carboxymethyl Cellulose) 1 % dari ekoenzim kulit buah pisang. Isolat CKM2 dan PS03 menjadi isolat terpilih karena didasarkan pada nilai indeks aktivitas selulolitik dan penapisan aktivitas enzim terbesar yang tidak menunjukkan hasil uji positif hemolisis. Isolat CKM2 memiliki aktivitas enzim spesifik tertinggi sebesar 0.908 U/mg pada jam ke-48 dengan aktivitas enzim optimum pada suhu 30 οC dan pH 7. Isolat PS03 memiliki aktivitas enzim spesifik tertinggi sebesar 1.184 U/mg pada jam ke-30 dengan aktivitas enzim optimum pada suhu 40 οC dan pH 5., Cellulose is the most abundant component of plant biomass, which is insoluble in water because of its complex structure. The use of cellulase enzymes can be the key to the efficient and effective degradation of cellulose materials. Utilization of ecoenzymes can reduce the amount of household waste which is usually dominated by organic waste. Ecoenzymes are complex organic liquids produced from the fermentation process of fresh fruit waste, sugar, and water in a ratio of 3:1:10 after three months of fermentation. This study aims to isolate and characterize cellulolytic bacteria derived from ecoenzymes fermented by banana peels. Nine cellulolytic bacteria were isolated and grown on 1 % selective CMC (Carboxymethyl Cellulose) medium from banana peel ecoenzyme. CKM2 and PS03 isolates were the selected isolates based on the cellulolytic activity index value and the largest enzyme activity screening which did not show a positive hemolysis test result. CKM2 isolate had the highest specific enzyme activity of 0.908 U/mg at the 48th hours with optimum enzyme activity at 30 οC and pH 7. Isolate PS03 had the highest specific enzyme activity of 1.184 U/mg at the 30th hours with optimum enzyme activity at 40 οC and pH 5.
Keyword: Banana peel, cellulose, cellulolytic index, fermentation, fruit waste

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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