Judul: Penapisan Bakteri Lipolitik asal Fruktosfer Kelapa Sawit
Abstrak: Lipase (EC 3.1.1.3, glycerol ester hidrolase) is defined as carboxylesterase that catalyzes the hydrolysis of long chain asilgliserol. Lipase produced by lipolytic bacteria that grow well in substrates containing oils such as oil palm fruit. The purpose of this study was to screen lipolytic bacteria from oil palm fructosphere and to characterize optimal pH and temperature of lipase enzyme from selected isolates. Seven isolates of lipolytic bacteria with different morphology were qualitatively screened from oil palm fructosphere using Rhodamin B media. Bacteria were isolated from the exocarp and mesocarp of ripe oil palm fruits. Lipolytic activity each isolates were measured and selected based on their activity. Three isolates possessed the best activity with result as follows EP2.22 (0.912 U/mg), F2 (0.792 U/mg), and F6 (0.650 U/mg). These isolates showed high activity at various range of pH and temperature. Isolate EP2.22 showed optimum pH at 7.5 and optimum temperature at either 40 oC or 70 oC. Isolate F2 showed optimum pH 8.5 and optimum temperature 70 oC. Isolate F6 showed optimum pH 8.5 and optimum temperature at 30 oC and 70 oC. Two peaks of high activity due to the use of crude enzyme extract. 16S rRNA gene sequencing indicated that isolates EP2.22, F2, and F6 closely related to Staphylococcus klosii Enterobacter sp., and Buttiauxella izardii.
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Judul: Analisis Komunitas Bakteri Fruktosfer Kelapa Sawit Menggunakan Teknik Terminal Restriction Fragment Length Polymorphism (T-RFLP)
Abstrak: The knowledge about bacterial community could provide basic information for the development of further research. One method that could be used to analize the diversity of microbial community is Terminal Restriction Fragment Length Polymorphism (T-RFLP). The objective of this research is to analyze the existing bacterial diversity on oil palm fructosphere. The 16S rRNA genes were amplified by PCR using forward primer (27F) and reverse primer (926R) which have been labeled. The PCR product were then digested with four different enzymes, namely BstUI, MspI, DdeI, and Sau96I. The elecroforegram showed that these enzymes produce different patterns due to the unique restriction sites of each enzymes. In general, BstUI and MspI enzymes produce more Terminal Restriction Fragment (TRF) than two other enzymes. From T-RFLP analysis we could identify some bacterial genus. Bacteria that were predicted to be present in oil palm fructosphere were gram-positive and gram-negative bacteria, Proteobacteria, Actinobacteria, soil bacteria, marine bacteria, and bacteria that could not be cultured.
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Judul: Pengaruh panjang deret waktu data terhadap perhitungan debit banjir rencana
Abstrak: Dalam perencanaan bangunan air, harus ditunjang oleh data yang lengkap. Pada kenyataannya data yang lengkap dewasa ini sulit diperoleh. Selain itu pengambilan data ini memerlukan waktu, ketepatan, ketelitian serta biaya yang cukup besar. Tujuan dari penelitian ini adalah mempelajari pengaruh panjang data terhadap perhitungan banjir rencana, menentukan besarnya banjir maksimum yang akan terjadi untuk periode waktu yang berbeda, serta menentukan distribusi banjir teoritis yang paling sesuai pada daerah yang diteliti. Menurut Chow (1964), di dalam analisa hidrologi digunakan asumsi bahwa kejadian-kejadian selama pengamatan cukup mewakili dan hasil pengamatan tersebut dapat dipercaya. Kepercayaan semakin meningkat dengan bertambah lamanya pencatatan data. Dalam kenyataannya, lama pencatatan data yang dilakukan tergantung dari periode ulang yang akan digunakan dalam mendesain suatu bangunan. Menduga suatu kejadian dengan periode ulang yang lebih besar daripada periode pencatatan menyebabkan hasil pendugaan tidak dapat dipercaya....
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