Judul: Optimasi Media Produksi Lactobacillus plantarum TSD-10 dengan Response Surface Methodology (RSM) Sebagai Probiotik Sapi.
Abstrak: Bakteri asam laktat (BAL) merupakan salah satu mikroorganisme yang sudah umum digunakan sebagai probiotik. Bakteri ini membutuhkan media kompleks untuk tumbuh seperti medium MRS (de Man Rogosa and Sharpe). Media produksi menggunakan MRS biayanya sangat tinggi, diperlukan media alternatif yang efisien dan optimum untuk pertumbuhan probiotik. Tujuan penelitian ini untuk mendapatkan media optimum untuk produksi probiotik Lactobacillus plantarum TSD-10 menggunakan metode Response Surface Methodology (RSM), mengukur viabilitas probiotik, dan menguji aktivitas penghambatan probiotik terhadap Eschericia coli dan Staphylococcus aureus. Kondisi optimum media produksi L. plantarum dengan jumlah sel sebesar 10.56  109 CFU/mL (CFU = colony forming unit) adalah konsentrasi glukosa 1.48% (w/v), molase 3.72% (v/v), mineral mix 0.34% (w/v), dan protein mix 7.69% (v/v). Viabilitas probiotik pada suhu ruang sangat rendah hanya mampu disimpan selama 2 minggu. Penyimpanan pada refrigerator dapat mempertahankan viabilitas probiotik selama 6 minggu. Aktivitas penghambatan probiotik terhadap E. coli lebih besar dibanding aktivitas penghambatannya terhadap S. aureus.
Keyword: antibakteri, Lactobacillus plantarum TSD-10, media produksi, RSM, viabilitas

Judul: Optimasi Produksi Antimikroba dari Lactobacillus plantarum LIPI13-2-BAL011 dengan Simulasi Permukaan Respon
Abstrak: Lactobacillus plantarum merupakan spesies bakteri asam laktat (BAL) yang telah banyak digunakan sebagai antimikroba. Penelitian ini bertujuan melakukan optimasi produksi antimikroba dari L. plantarum LIPI13-2-BAL011 menggunakan simulasi permukaan respon (RSM) terhadap Staphylococcus aureus, Bacillus subtilis dan Candida albicans. Optimasi produksi isolat L. plantarum dilakukan dengan kombinasi glukosa, NaCl, inokulum, dan suhu berbeda selama 48 jam. Aktivitas daya hambat dilakukan dengan metode difusi cakram dan dilusi cair. Isolat L. plantarum LIPI13-2-BAL011 lebih optimal menghasilkan senyawa antimikroba dalam media cair de Mann Rogose Sharpe (MRS) pada keadaan statis. Kondisi optimum produksi antimikroba terhadap S. aureus dengan persen penghambatan representatif 99.34% adalah menggunakan substrat glukosa 1.99%, NaCl 3.01%, inokulum 3.74%, dan suhu 31.6 oC. Kondisi optimum produksi antimikroba terhadap C. albicans dengan indeks zona bening representatif 1.9160 adalah glukosa 1.63%, NaCl 3.4%, inokulum 3.03%, dan suhu 33.74 oC. Kondisi optimum produksi antimikroba terhad
Keyword: antimicrobial, Lactobacillus plantarum LIPI13-2-LAB011, RSM

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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