Judul: SYNBIOTIC CALIFORNIA PAPAYA SEED EXTRACT (Carica papaya L.) WITH Lactobacillus plantarum IN INHIBITING PATHOGENIC BACTERIA
Abstrak: Kombinasi probiotik dan prebiotik atau sinbiotik saat ini menjadi perhatian para peneliti karena memberikan manfaat sinergis serta potensinya sebagai alternatif antibiotik. Probiotik yang digunakan yaitu Lactobacillus plantarum dan biji pepaya sebagai sumber prebiotik. Penelitian ini bertujuan menguji kemampuan ekstrak biji Carica papaya L. sebagai prebiotik untuk L. plantarum serta daya hambatnya terhadap Escherichia coli dan Pseudomonas aeruginosa. Ekstraksi biji dilakukan dengan cara maserasi menggunakan pelarut aquades. Sampel uji prebiotik terdiri atas L. plantarum dalam media MRS (de Man Rogosa Sharpe) komersial tanpa ekstrak, MRS basal tanpa ekstrak, MRS basal dengan ekstrak 2,5% dan 5% dengan waktu inkubasi 24, 48, 72, dan 96 jam pada suhu 37 oC. Pengujian daya hambat pada ekstrak terpilih menggunakan metode difusi agar dengan cara sumuran dan diinkubasi selama 24−48 jam. Hasil uji prebiotik dianalisa dengan metode one-way ANOVA. Penambahan ekstrak 5% meningkatkan jumlah pertumbuhan L. plantarum. Sinbiotik dengan ekstrak biji pepaya 5% memiliki daya hambat sedang terhadap E. coli dan P. aeruginosa., The combination of probiotics and prebiotics or synbiotics is a currently a concern because it provides synergistic benefits and potential as an alternative antibiotic. The probiotic used is Lactobacillus plantarum and papaya seeds as a source of prebiotics. This study aims to test the capability of Carica papaya L. seed extract as a prebiotic for L. plantarum and its inhibitory power against Escherichia coli and Pseudomonas aeruginosa. Seeds extraction with maceration method using distilled water solvent. Prebiotic test samples consisted of L. plantarum in commercial MRS (de Man Rogosa Sharpe) medium without extract, basal MRS without extract, and basal MRS with 2.5% and 5% extract with incubation times of 24, 48, 72, and 96 hours at 37 oC. Inhibition testing on selected extract using agar diffusion method with wells and incubated for 24−48 hours. The results of the prebiotic test were analyzed with one-way ANOVA method. The addition of 5% extract increased the amount of L. plantarum growth. Synbiotics with 5% extract had moderate inhibition against E. coli and P. aeruginosa.
Keyword: biji pepaya, Lactobacillus plantarum, sinbiotik, uji difusi

Judul: Keefektifan bakteri antagonis terhadap penyakit busuk akar (Phytophthora palmivora) pada bibit pepaya
Abstrak: Pepaya (Carica papaya L.) merupakan tanaman buah penting di Indonesia. Tanaman pepaya dapat terinfeksi penyakit sejak masih dalam bentuk bibit seperti busuk akar yang disebabkan oleh Phytophthora palmivora. Penelitian ini bertujuan mengetahui keefektifan bakteri antagonis dalam mengendalikan penyakit busuk akar pada bibit pepaya. Penelitian ini dilaksanakan di Laboratorium Pusat Kajian Hortikultura Tropika (PKHT), Institut Pertanian Bogor. Metode penelitian yang digunakan yakni uji dual culture isolat bakteri terhadap P. palmivora, uji in planta bakteri terhadap penyakit busuk akar dalam kondisi rumah kaca, dan uji in planta bakteri uji terhadap aktivitas pengaruh pertumbuhan tanaman. Masing-masing uji menggunakan lima jenis bakteri (G4, J8, K1, P14, dan Pseudomonas aeruginosa) dan kontrol. Rancangan percobaan yang digunakan yaitu rancangan acak lengkap untuk uji dual culture, rancangan acak kelompok (RAK) untuk uji in planta. Semua data hasil pengamatan diolah dengan analisis ragam menggunakan program Microsoft Office 2013 dan Statistical Analysis System (SAS) for windows versi 9.1.3. Uji lanjut menggunakan uji selang ganda Duncan pada taraf nyata α = 0.05. Seluruh isolat bakteri antagonis mampu menekan penyakit pada nilai 25 − 35%. Bakteri G4 dan P. aeruginosa mampu meningkatkan daya berkecambah benih pepaya.
Keyword: biocontrol agents, papaya, Phytophthora palmivora

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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