Judul: Isolasi, pemurnian dan identifikasi senyawa anti-B-laktamase dari streptomyces sp. IVNF1-1(Penghambat pertumbuhan bakteri penyebab diare, EPEC K1-1
Abstrak: Bakteri penyebab diare (EPEC K1-1) memproduksi ß-laktamase, enzim yang memotong cincin ß-laktam dan menimbulkan resistensi EPEC K1-1 terhadap antibiotik ß- laktam. Dalam penelitian ini, upaya mengatasi resistensi dilakukan melalui isolasi senyawa anti-ß-laktamase golongan protein (BLIP) dan asam klavulanat dari Streptomyces sp. IVNF1-1. Upaya ini dilatarbelakangi keragaman mikrob Indonesia yang sangat tinggi dan IVNF1-1 merupakan isolat indigenos potensial yang memberikan hambatan terhadap pertumbuhan EPEC K1-1 dengan diameter zona hambat sebesar 6 mm. Hambatan protein ekstraselular IVNF1-1 terhadap aktivitas enzim ß-laktamase EPEC K1-1 ditentukan dengan metode iodometri yang telah dimodifikasi. Hambatan yang diberikan protein ekstraselular dalam filtrat kultur IVNF1-1 ialah sebesar 84,12%. Pemurnian protein tersebut melalui pengendapan amonium sulfat kejenuhan 80%, dialisis, dan kromatografi filtrasi gel sephadex G-75 menghasilkan BLIP dengan aktivitas hambatan sebesar 11,10%.
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Judul: Ability of anti-β-lactamase Streptomyces lavendulae IVNF1-1 as a supporting compound for β-lactam to inhibit EPEC K1-1 cell wall synthesis.
Abstrak: Enteropathogenic Escherichia coli (EPEC) is a causing agent of diarrhea because it can adhere to apical plasma membrane of enterocyte cell and disrupt the electrolyte balance inside it. Widely used of β-lactam antibiotics against EPEC has stimulated resistance of it through β-lactamase formation. It has been known that Streptomyces lavendulae IVNF1-1 has anti-β-lactamases comprise of β-Lactamase Inhibitory Protein (βLIP) and clavulanic acid. The anti-b-lactamase compounds probably can be used as a supporting compounds for β-lactam antibiotics to control the growth of β-lactam-resistant-EPEC. The aim of this study was to examine the ability of anti-β-lactamase produced by S. lavendulae IVNF1-1 in supporting the function of β-lactam antibiotic in inhibiting EPEC cell wall synthesis. Clavulanic acid as well as βLIP inhibited the growth of EPEC K1-1. Adding of βLIP and clavulanic acid to 5 ml NB media which contain 100 μg/ml ampicilin and EPEC with 12 hour incubation in 37° C lowered the cell number of EPEC K1-1, indicating that combining the two anti-β-lactamase compounds increased their effectiveness. Synergism effect occured when both βLIP and clavulanic acid were combined at 4.7% (b/v) and 2% (v/v), respectively. Addition of two anti-β-lactamase compounds either separately or mixedly, has made the cell morphology of EPEC K1-1 longer in shape and broken in its cell appearance. Its cell wall has lysed. Anti-β-lactamase compounds of S. lavendulae IVNF1-1 are proven to be supporting compounds for ampicillin during inhibition of EPEC K1-1 cell.
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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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