Judul: Isolasi, pemurnian dan identifikasi senyawa anti-B-laktamase dari streptomyces sp. IVNF1-1(Penghambat pertumbuhan bakteri penyebab diare, EPEC K1-1
Abstrak: Bakteri penyebab diare (EPEC K1-1) memproduksi ß-laktamase, enzim yang memotong cincin ß-laktam dan menimbulkan resistensi EPEC K1-1 terhadap antibiotik ß- laktam. Dalam penelitian ini, upaya mengatasi resistensi dilakukan melalui isolasi senyawa anti-ß-laktamase golongan protein (BLIP) dan asam klavulanat dari Streptomyces sp. IVNF1-1. Upaya ini dilatarbelakangi keragaman mikrob Indonesia yang sangat tinggi dan IVNF1-1 merupakan isolat indigenos potensial yang memberikan hambatan terhadap pertumbuhan EPEC K1-1 dengan diameter zona hambat sebesar 6 mm. Hambatan protein ekstraselular IVNF1-1 terhadap aktivitas enzim ß-laktamase EPEC K1-1 ditentukan dengan metode iodometri yang telah dimodifikasi. Hambatan yang diberikan protein ekstraselular dalam filtrat kultur IVNF1-1 ialah sebesar 84,12%. Pemurnian protein tersebut melalui pengendapan amonium sulfat kejenuhan 80%, dialisis, dan kromatografi filtrasi gel sephadex G-75 menghasilkan BLIP dengan aktivitas hambatan sebesar 11,10%.
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Judul: Aktivitas senyawa anti β-laktamase dari Streptomyces lavendulae IVNF1-1 terhadap iabilitas enteropathogenic escherichia coli (EPEC) K1-1 resisten ampisilin
Abstrak: Antibiotik yang banyak digunakan adalah antibiotik β-laktam, diantaranya adalah penisilin, sefalosporin, dan sefamisin. Penghambatan yang spesifik pada pembentukan lapisan peptidoglikan menjadikan antibiotik β-laktam bersifat selektif, yaitu hanya menghambat pertumbuhan bakteri target tanpa membahayakan sel inang sehingga pemakaian antibiotik ini aman bila dibandingkan antibiotik jenis lain. Resistensi bakteri terhadap antibiotik β-laktam merupakan masalah yang serius di bidang kesehatan. Bakteri menjadi resisten terhadap antibiotik ini karena dapat menghasilkan enzim β-laktamase yang bekerja memecah dan menghidrolisis ikatan amida pada cincin β-laktam sehingga antibiotik ini tidak efektif lagi untuk pengobatan. Enzim β-laktamase dapat diinaktifkan oleh senyawa anti β-laktamase. Aktivitas senyawa anti β-laktamase yang dihasilkan oleh Streptomyces isolat lokal seperti isolat IVNF1-1 diketahui melalui dihasilkannya asam klavulanat dan β-laktamase Inhibitory Protein (BLIP). Aktivitas asam klavulanat dan BLIP dari Streptomyces lavendulae IVNF1-1 dalam menghambat pertumbuhan bakteri patogen belum diketahui sehingga perlu dilakukan penelitian ini. Penelitian ini bertujuan mengkaji aktivitas senyawa anti β-laktamase dari Streptomyces lavendulae IVNF1-1 yaitu asam klavulanat dan BLIP terhadap viabilitas EPEC K1-1 resisten ampisilin.
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Judul: Thermal Characteristics and Dynamics of Tropical Cyclone over Western North Pacific Ocean: A Case Study of Typhoon Songda (Chedeng) 2011
Abstrak: The frequent occasion of Tropical Cyclone (TC) over Western North Pacific (WNP) Ocean lies from 10˚N to 26˚N and 121˚E to 170˚E. Sources of TC development come from warm ocean temperature where latent heat is released during condensation processes and subsequently concentrated in the boundary layer. Relative humidity at 850-700 hPa is responsible to produce the most intense storm. Meanwhile, weak vertical wind shear between 850-200 hPa is one of the dynamical factors that lead to the development of TC. Pressure level of 850-200 hPa is chosen to minimize the thermodynamic effect in the lower troposphere. Typhoon Songda (Chedeng in the Philippines) or TSC lasted from May 18th to 30th, 2011 and strengthened into powerful Super Typhoon stage between May 24th and 27th. Long curving track and the exhibition of all sequences of TC life cycle, TSC is then considered as an ideal case of TC. The objective of the study with case of TSC is to investigate the role of thermal characteristics and dynamics on TC intensity. The research is carried out by using Advanced Research of Weather Research and Forecasting model (WRF ARW model) version 3.3. Two domains are employed in the model. The first domain situate from 02˚N to 40˚N and 118˚E to 149˚E and cover spatial resolution () of 33.1 km. The second domain situate from 09˚N to 27˚N and 119˚E to 132˚E with of 11 km. Timestep of the model () is 120 seconds. The model is supported by the following physical parameterization, i.e., Yonsei University Scheme (YSU) in the boundary layer, Kain-Fritsch scheme (KF) in the cumulus, and WRF Single-Moment 3-class scheme in the microphysics. Initial meteorological condition prior to the formation of the cyclone is generated using WRF ARW standard-release model. Sensitivity of the model output is obtained from a selected single-parameter change scenarios, namely, 10 % to 20 % decrease and increase of wind shear initial data at 850-200 hPa, and by 10 % to 20 % decrease of relative humidity initial data at 850-700 hPa. The result showed that the negative correlations between wind shear and intensity are found in wind shear scenarios. Wind shears of 10 ms-1 which lead to strengthening of the wind intensity in the early period of Typhoon development are found in wind shear scenarios. The effect of wind shear changes on wind intensity is statistically significant in the 20 % wind shear scenarios. During mature stage, weak wind intensity occurred when wind shear increase as given in the WRF standard-release and the 20 % decreasing scenario. Different situation is found in the 20 % increasing scenario where wind shear tend to weak and lead to strong wind intensity at this stage. Meanwhile, the reduction of moisture supply at 850-700 hPa resulting from 20 % decreasing relative humidity play a major role in the weakening of wind intensity and reduces mechanical energy of the cycle process as much as 300 J kg-1.
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