Judul: Decomposition of Agathis dammara (Lamb.) Leaves,  Soil Fauna Abundance, and Soil Characteristics in Gunung Walat University  Forest
Abstrak: Serasah adalah sumber nutrisi bagi unsur biotik di sekitarnya. Fauna tanah berperan dalam dekomposisi serasah, menguraikan unsur hara, dan memengaruhi siklus nutrisi. Penelitian ini bertujuan menganalisis hubungan antara faktor edafis dan klimatis terhadap laju dekomposisi daun serta mengidentifikasi fauna tanah di bawah tegakan Agathis dammara (Lamb.). Pengambilan sampel dilakukan pada petak contoh 20 m x 20 m secara acak dengan sub-plot systematic sampling 0,5 m x 0,5 m. Hasil analisis menunjukkan laju dekomposisi pada minggu ke 4, 8, dan 12 secara berturut-turut sebesar 0,92 g/minggu, 1,51 g/minggu, dan 1,29 g/minggu. Korelasi antara laju dekomposisi dengan faktor edafis seperti pH, suhu, kelembapan, respirasi, bahan organik, dan c-organik menunjukkan korelasi positif. Faktor klimatis juga berpengaruh: kelembapan udara dan suhu udara memiliki korelasi positif, sedangkan intensitas cahaya menunjukkan nilai negatif. Indeks keanekaragaman fauna tanah berkisar antara 0,30-1,90; nilai kemerataan berkisar antara 0,15-0,82; dan nilai kekayaan berkisar antara 0,63-2,10; yang menunjukkan indeks keanekaragaman yang tergolong rendah hingga sedang.
Keyword: soil fauna

Judul: Decomposition rate of leaf litter at Density Class I and II in the Rehabilitation Zone of Mount Halimun Salak National Park
Abstrak: Salah satu bahan organik alami yang dihasilkan dari tanaman yaitu serasah. Serasah menjadi tempat proses biologi tanah yaitu dekomposisi. Dekomposisi memegang peranan yang penting dalam siklus ekologi di hutan yang merupakan asupan unsur hara ke dalam tanah. Penelitian ini bertujuan untuk memberikan informasi terkait pengaruh vegetasi terhadap laju dekomposisi dan karakteristik tanah serta memberikan informasi terkait pengaruh faktor edafis dan klimatis terhadap laju dekomposisi di zona rehabilitasi Taman Nasional Gunung Halimun Salak. Dekomposisi serasah dilakukan menggunakan litterbag yang diletakkan pada plot berukuran 50 m x 50 m. Hasil penelitian selama 90 hari menunjukkan bahwa laju rata-rata dekomposisi serasah pada hari ke-30 sebesar 0,37 g/hari (Kelas I) dan 0,41 g/hari (Kelas II) dan terus mengalami peningkatan hingga hari ke-90 sebesar 0,41 g/hari (Kelas I) dan 0,47 g/hari (Kelas II). Peningkatan laju dekomposisi memiliki korelasi positif terhadap unsur klimatis (suhu udara, kelembapan, dan intensitas cahaya) dan unsur edafis yaitu sifat fisika tanah (porositas dan suhu tanah), sifat kimia tanah (pH tanah, bahan organik tanah, C-organik, dan N-total), dan sifat biologi (respirasi tanah). Laju dekomposisi berkorelasi negatif dengan bulkdensity dan C/N rasio., One of the natural organic materials produced from plants is litter. Litter becomes the site of the biological process of soil that is decomposition. Decomposition plays an important role in the ecological cycle in forests which is the intake of nutrients into the soil. This study aims to provide information related of vegetation on the rate of decomposition and soil characteristics and determine the influence of edafic and climatic factors on the rate of decomposition in the rehabilitation zone of Mount Halimun Salak National Park. Litter decomposition is carried out using litterbags placed on plots measuring 50 m x 50 m. The results of the 90-day study showed that the average rate of litter decomposition on the 30th day was 0,37 g/day (Class I) and 0,41 g/day (Class II) and continued to increase until the 90th day of 0,41 g/day (Class I) and 0,47 g/day (Class II). The increase in the rate of decomposition has a positive correlation with climatic elements (air temperature, humidity, and light intensity) and edafic elements, namely soil physical properties (porosity and soil temperature), soil chemical properties (soil pH, soil organic matter, C-organic, and N-total), and biological properties (soil respiration). Meanwhile, the rate of decomposition is negatively correlated with bulkdensity and C/N ratio.
Keyword: dekomposisi, edafis, klimatis, serasah, TNGHS

Judul: Pemurnian dan karakterisasi protein inhibitor RNA helikase virus hepatitis C
Abstrak: Hepatitis C virus (HCV) infection is the second most common chronic viral infection in the world with global prevalence. This infection is contribution to chronic hepatitis and liver cirrhosis, often leading to hepatocellular carcinoma. There is no effective drug and vaccine available against HCV. The current standard treatment, a combination of pegylated interferon-α with ribavirin, is limited by its suboptimal response rate in a significant patient population, side effects, and affordability. Therefore, development of effective drug is needed. One approach to find out the candidate of antiviral drug is to discover the inhibitor of enzyme that essential for virus replication, such as RNA helicase. Streptomyces chartreusis 5-095 produce the inhibitor of HCV RNA helicase. The aim of this study was to purify the protein inhibitor which has inhibition activity against ATPase activity of RNA helicase HCV from S. chartreusis 5-095. The supernatant of culture S. chartreusis 5-095 exhibited high inhibiton activity against ATPase activity of RNA helicase HCV (approximately 72%) at 10 days of incubation. The extracellular protein inhibitor was partially purified by procedures of precipitation with ammonium sulfate to 65% saturation and gel filtration (Sephadex G50) using methanol water solution (4:6) as an eluen. The purity of protein inhibitor was monitored by SDS PAGE. The protein inhibitor showed a relative molecular mass were estimated to be 14 kDa and increased the purity 23,08 fold than those of the crude protein. The specific activity and IC50 after purification were 13,1338 U/mg and 0,0767 mg/mL, respectively. The activity of purified protein inhibitor showed its stability over pH range from 5-8 and optimum at pH 7,4. The inhibition activity showed its stability up to 70% at temperature 100 oC. The purified protein inhibitor relatively stable its activity at storage in the range of -20 oC to room temperature for 35 days.
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