Judul: Bakteri Asam Laktat Asal Bekasam Penghasil Lipase Pada Substrat Margarin
Abstrak: Enzim lipase pada mikroorganisme memiliki potensi yang besar di bidang kesehatan, industri dan proses bio-diesel. Mikroorganisme penghasil lipase diantaranya adalah bakteri asam laktat (BAL). Margarin merupakan bahan pangan yang digunakan hampir pada setiap makanan. Penelitian ini bertujuan untuk mendapatkan isolat BAL asal bekasam yang memiliki potensi lipolitik pada substrat margarin. Delapan belas isolat asal bekasam terkoleksi di laboratorium disegarkan kembali pada media MRSA suhu 37ºC selama 48 jam kondisi anaerob. Isolat terpilih diuji potensi penghasil lipolitik pada substrat margarin 1% menggunakan indikator Rhodamine B dan dilihat di bawah UV 365 nm, diidentifikasi nama spesies dengan API KIT 50 CHL. Isolat terpilih diukur kurva pertumbuhan dan aktivitas lipase. Isolat BI(2), BP(3), BP(6), SK(5), dan NS(6) menunjukkan kemampuan mendegradasi lipid pada margarin dengan pendaran warna jingga. Isolat BI(2) memiliki pendaran terkuat. Hasil identifikasi isolat BAL BI(2) adalah Lactococus lactis spp. lactis dengan nilai ID 82.40%. Jumlah sel dan aktivitas unit lipase tertinggi Lactococcus lactis terlihat pada fase log akhir yaitu jam ke-12 sebesar 4.741 CFU/mL dan 29.812 unit/mL.
Keyword: bakteri asam laktat, bekasam, Lactococcus lactis, lipase, margarin

Judul: Activity Lipolytic of Lactic Acid Bacteria from Peranakan Ongole Beef
Abstrak: Selain kemampuannya sebagai strarter fermentasi, bakteri asam laktat (BAL) juga dikenal sebagai produsen enzim yang aplikatif di industri. Salah satu enzim yang dihasilkan oleh BAL adalah lipase, yaitu kelompok enzim yang menghidrolisis lemak (lipid), yang memiliki aplikasi yang luas di berbagai industri. Sebelumnya, 20 strain BAL telah diisolasi dari daging sapi segar lokal Peranakan Ongole (BAL-Ongole). Meskipun demikian, aktivitas lipase dari BAL tersebut belum diketahui. Tujuan penelitian ini adalah untuk mengetahui aktivitas lipolitik isolat BAL-Ongole. Dalam penelitian ini, 3 isolat BAL-Ongole dipilih sebagai representasi, yaitu Lactobacillus plantarum IIA-1A5, Enterococcus faecium 2D2, dan Pediococcus pentosaceus 2A2. Sebelum digunakan morfologi ketiga isolat tersebut dikonformasi dengan menggunakan pewarnaan Gram. Pengujian aktivitas lipase kemudian dilakukan dengan menggunakan metode sumur dengan menumbuhkan isolat tersebut pada MHA (Mueller Hinton Agar) yang ditambah Tributyrin 1% sebagai substrat lipase, kemudian diinkubasi dengan kondisi kedap udara (anaerob) pada suhu 37 ̊C selama 24 jam. Aktivitas lipase ditunjukkan dengan terbentuknya zona bening disekitar lubang sumur. Hasil menunjukkan bahwa E. faecium 2D2 memiliki aktivitas lebih tinggi dibandingkan kedua BAL lainnya. Aktivitas lipolitik tertinggi terlihat pada isolat E. faecium 2D2 sebesar 9,60 mm dengan kondisi optimum pada suhu 50 ̊C dan pH 9. Aktivitas spesifik enzim diketahui sebesar 0,016U/μL. Meskipun aktivitas lipolitik bakteri ini masih lebih rendah dari kontrol, akan tetapi proses pemurnian enzim ini diprediksi bisa meningkatkan aktivitasnya sebanding dengan kontrol., Apart from their widely-known ability as fermentation starters, lactic acid bacteria (LAB) is known to be the good producers for various enzyme, including lipase enzyme. This enzyme is able to catalyse the hydrolysis of lipid which are widely applicable in various industries. Earlier, 20 LAB isolates were optained from the fresh beef of Peranakan Ongole (LAB-Ongole), while these isolates are promising to be the good producers for lipase, their lipolytic activity have never been tested. This study aims to investigate the lipolytic activity of LAB-Ongole. For this purposes, 3 isolates of Ongole were used as representive, including Lactobacillus plantarum IIA-1A5, Enterococcus faecium 2D2, dan Pediococcus pentosaceus 2A2. The morphological-based purity of these isolates were confirmed using Gram staining prior to the lipolytic test. The tes was done using well-diffusion agar, whereby the isolate suspension was placed onto the well of MHA (Mueller Hilton Agar) with 1% Tributyrin as the lipase substrate. The agar wa then incubated at 37 ̊C for 24 h. The result showed that E. faecium 2D2 exhibited the highest lipolytic activity than the two other isolates. The optimum lipolytic activity of 2D2 isolate was 9,60 mm at 50 ̊C and pH 9. The specific activity of lipase from 2D2 isolate was found tobe 0,016 U/μL. While this activity was remarkably lower than the control (commercial lipase), the lipase of 2D2 enable the enzyme to exhibit the activity as high as the control. Although the lipolytic activity of these bacteria was still lower than the control, but the purification process of this enzyme was predicted to increase its activity comparable to the control.
Keyword: aktivitas lipolitik, enzim lipase, Enterococcus faecium 2D2

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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