Judul: Konstruksi dan Ekspresi Gen Penyandi D-Xylose Isomerase di Escherichia coli BL21(DE3).
Abstrak: D-fruktosa merupakan gula pentosa yang berpotensi sebagai pionir rare sugar karena dapat diubah menjadi beberapa rare sugar lain yang multifungsi sebagai pemanis, bahan kosmetik, pengawet, penstabil, zat aditif, antidiabetes, dan antiobesitas. D-fruktosa dapat diisomerisasi secara enzimatis dengan menggunakan D-Xylose Isomerase (D-XI). D-XI disandi oleh gen xylA. Tujuan dari penelitian ini adalah mengkonstruksi vektor ekspresi untuk gen penyandi DXI, dan mengekspresikan D-XI di dalam Escherichia coli BL21 (DE3). Untuk itu, gen xylA penyandi D-XI dari Lactobacillus pentosus BTCC 646 telah berhasil diklon di dalam vektor pGEM-T Easy di dalam Escherichia coli DH5α. Nukleotida ke 225 dari gen xylA telah berhasil diubah dengan mutagenesis situs terarah agar tidak dikenali oleh enzim BamHI tanpa mengubah asam amino yang disandinya sehingga gen xylA225 dapat disisipkan ke dalam vektor ekspresi pET-32b pada situs BamHI. Vektor ekspresi pET-32b-xylA225 telah berhasil dimasukkan ke dalam E. coli BL21 (DE3). Gen xylA225 di dalam pET32b-xylA225 telah berhasil diekspresikan membentuk protein D-XI yang berfusi dengan Trx tag sehingga berukuran sekitar 69.3 kDa di dalam E.coli BL21 (DE3).
Keyword: D-fruktosa, D-Xylose Isomerase, vektor ekspresi, xylA, Escherichia coli

Judul: Isolasi, Konstruksi Vektor dan Ekspresi Isopenisilin N Synthase dari Penicillium chrysogenum di Escherichia coli BL21 (DE3)
Abstrak: Ekspresi protein yang berlebih (overexpression) di Escherichia coli dapat memicu terbentuknya badan inklusi. Strategi dalam meminimalisir terbentuknya badan inklusi dapat dilakukan dengan mengidentifikasi beberapa faktor yang berpengaruh seperti konsentrasi inducer IPTG, suplementasi gula dan suhu kultivasi. Penelitian ini bertujuan untuk melakukan konstruksi vektor ekspresi untuk gen pcbC penyandi isopenisillin N synthase (IPNS) dan identifikasi kondisi media tumbuh. Gen pcbC telah berhasil disisipkan ke dalam vektor pET32a sehingga terbentuk vektor ekpresi rekombinan pET32a::pcbC. Vektor rekombinan ini telah berhasil dimasukkan ke dalam E. coli BL21 (DE3) sebagai host ekspresi. E. coli BL21 (DE3) berhasil mensintesis protein target IPNS. Sintesis IPNS yang optimum terjadi pada kondisi media yang mengandung 0,1 mM IPTG, 1% sukrosa, 1% mannitol atau 1% sorbitol pada suhu kultivasi 20 oC
Keyword: Isopenicillin N synthase, pcbc gene, Penicillium chrysogenum, recombinant protein

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.
Keyword: