Judul: Eksplorasi Antibakteri Asal Kapang Tanah Arboretum Fakultas Kehutanan Institut Pertanian Bogor
Abstrak: Penelitian untuk menemukan antibakteri terbaru terus dilakukan karena mulai banyak bakteri patogen yang telah resisten terhadap beberapa antibakteri. Kapang tanah mempunyai potensi sebagai sumber antibakteri dengan cara menghasilkan metabolit sekundernya. Penelitian bertujuan mengisolasi kapang asal tanah Arboretum Fakultas Kehutanan Institut Pertanian Bogor. Sebanyak lebih kurang 7.5 gram sampel tanah diambil dari beberapa titik di Arboretum Fakultas Kehutanan Institut Pertanian Bogor dengan kedalaman maksimal 15 cm di bawah permukaan tanah. Isolat kapang yang telah didapatkan dilakukan kultivasi selama 28 hari menggunakan waterbath shaker. Miselium dan filtrat hasil kultivasi dipisahkan. Miselium diekstraksi dengan metode maserasi dengan pelarut diklorometana dan metanol. Filtrat diekstraksi dengan metode ekstraksi cair–cair dengan pelarut etil asetat. Hasil ekstraksi dilakukan pemekatan dengan rotary evaporator. Uji aktivitas antibakteri dilakukan dengan menggunakan metode agar well diffusion. Hasil uji aktivitas antibakteri pada ekstrak miselium dan ekstrak filtrat menunjukkan semua isolat kapang mempunyai aktivitas antibakteri terhadap bakteri uji S. aureus dan E. coli. Ekstrak filtrat dari isolate 103A membentuk zona hambat paling besar terhadap bakteri uji S. aureus dan E. coli.
Keyword: antibakteri, ekstraksi, kapang tanah, metabolit sekunder

Judul: Eksplorasi Antibakteri dari Kapang Tanah Institut Pertanian Bogor terhadap Multidrug Resistant Staphylococcus aureus
Abstrak: Penemuan antibakteri baru yang berasal dari metabolit sekunder asal kapang tanah mendorong pencarian potensi antibakteri baru yang dihasilkan oleh jenis kapang tanah yang berbeda. Penelitian ini merupakan penelitian lanjutan untuk mengeksplorasi potensi kapang tanah yang terdapat di Institut Pertanian Bogor. Sampel tanah diambil berjumlah 15 sampel masing-masing seberat 500 gram dari 5 tempat di sekitar Institut Pertanian Bogor dengan kedalaman 20 cm. Dari 15 sampel tanah didapati 9 isolat kapang tanah tumbuh, dikultivasi selama 28 hari tanpa pencahayaan dengan menggunakan waterbath shaker dan diekstrasi dengan menggunakan rotary evaporator pada suhu 40oC. Ekstraksi miselium menggunakan campuran larutan diklorometana dan metanol dengan perbandingan 1:1. Ekstraksi filtrat menggunakan metode ekstraksi cair-cair dengan larutan etil asetat. Pengujian antibakteri menggunakan metode agar well diffusion. Hasil uji menunjukan dari 9 isolat ekstrak filtrat kapang tanah terdapat 7 isolat yang membentuk zona hambat, sedangkan ekstrak milselium pada 9 isolat kapang tanah tidak membentuk zona hambat. Isolat 11 membentuk zona hambat paling besar dengan diameter 8 mm terhadap bakteri Multidrug Resistant Staphylococcus aureus.
Keyword: antibakteri, ekstrak filtrat, kapang tanah, metabolit sekunder

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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