Judul: Aktivitas Antibakteri Enterophatogenic Escherichia coli (EPEC) K11 dari Plantarisin F Rekombinan Hasil Purifikasi
Abstrak: Salah satu bakteri penyebab diare adalah enterophatogenic Escherichia coli (EPEC) K11. Pengobatan diare menggunakan antibotik secara terus menerus dapat menimbulkan resistensi. Plantarisin F rekombinan merupakan salah satu peptida antimikroba yang dihasilkan oleh Lactococcus lactis pNZ8148 rekombinan F dan berpotensi sebagai alternatif penggunaan antibiotik. Penelitian ini bertujuan menentukan aktivitas antibakteri EPEC K11 dari plantarisin F rekombinan hasil purifikasi. Proses purifikasi dilakukan dengan pengendapan garam amonium sulfat, kromatografi kolom filtrasi gel Sephadex G-50, dan kromatografi kolom penukar kation SP Sepharose. Sampel hasil purifikasi diuji aktivitas antibakterinya terhadap EPEC K11 dengan metode difusi agar. Pelet hasil pengendapan garam amonium sulfat, fraksi hasil kolom filtrasi gel, dan fraksi hasil kolom penukar kation memiliki aktivitas spesifik berturut-turut 235.107 AU/mg, 268.553 AU/mg, dan 6074.405 AU/mg. Aktivitas antibakteri tertinggi diperoleh pada sampel pelet hasil pengendapan garam amonium sulfat 60% dengan diameter zona bening sebesar 8 mm.
Keyword: antibacterial, enterophatogenic Escherichia coli (EPEC), plantaricin F recombinant, purification

Judul: Penghambatan Enteropatogenik Escherichia Coli (Epec) K11 Oleh Plantarisin E Rekombinan Dengan Perlakuan Edta
Abstrak: Bakteri Enteropatogenik Eschericia coli (EPEC) tergolong dalam bakteri gram negatif termasuk salah satu penyebab penyakit diare. Pengobatan secara umum dilakukan menggunakan antibiotik, namun EPEC K11 mengalami resitensi antibiotik sehingga diperlukan alternatif pengobatan lain. Salah satu alternatifnya adalah peptida antimikroba dari golongan bakteriosin dihasilkan oleh Lactococcus lactis pNZ 8148 Pln E, yaitu plantarisin E rekombinan. Aktivitas antimikroba plantarisin terhadap bakteri gram negatif dapat ditingkatkan dengan penambahan agen pengkelat seperti EDTA. Penelitian ini bertujuan menguji potensi antimikroba plantarisin E rekombinan terhadap penghambatan EPEC K11 dengan penambahan EDTA. Metode yang dilakukan meliputi produksi plantarisin dengan menumbuhkan Lactococcus lactis pNZ 8148 Pln E pada media M17 glukosa. Uji aktivitas plantarisin dilakukan secara kualitatif berdasarkan metode difusi agar. Purifikasi plantarisin menggunakan amonium sulfat dan kolom SP Sepharose. Plantarisin hasil purifikasi ditambahkan EDTA sebanyak 1% v/v dengan berbagai macam konsentrasi dari 1 mM, 5 mM, 10 mM dan 20 mM. Hasil produksi plantarisin diperoleh 200 ml supernatan bebas sel. Hasil purifikasi dengan kolom SP Sepharose menunjukan aktivitas plantarisin sebesar 28.62 AU/mg dengan kandungan total protein sebesar 3.93 mg. Penurunan aktivitas plantarisin akibat pemurnian sebesar 56.25 %. Hasil SDS PAGE menunjukan bobot molekul plantarisin E adalah 3.7 kDa. Perlakuan penambahan EDTA memperlihatkan peningkatan aktivitas penghambatan sebesar 0.5 hingga 4 mm.
Keyword: Antimikroba, EDTA, Lactococcus lactis, purifikasi

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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