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: Characteristic of Overshooting Top (OT) Based on  Himawari  8  Satellite  as  a  Convective  Cloud  Feature  that  Generates  Extreme Weather in the Java Island Region
Abstrak: Overshooting Top (OT) is a feature at the top of a convective cloud that is associated with extreme weather. Research on OT in tropical Indonesia is still very limited. The existence of geostationary satellites with wide area coverage and fast frequency observations is useful for observing the fast dynamics of the OT life cycle. Therefore, this study intends to analyze the relationship between OT and extreme weather, updraft and thermodynamic conditions of OT when extreme weather occurs, the best objective method for detecting OT in the day time and night time, and the spatiotemporal distribution of OT in the tropical region of Java Island during the 2018-2021 period. Based on visual analysis using visible channel and Himawari 8 sandwich products, 87% of extreme weather events in Java were accompanied by the appearance of OT. It indicates that the presence of the OT pattern is a convection cloud pattern or feature that is closely related to extreme weather events for the Java Island region. The existence of a time lag between the appearance of OT and extreme weather events on Java Island indicates that the OT of convection cloud can be used as a precursor or nowcasting for the appearance of extreme weather. Most of the convective cloud OT features during extreme weather events on Java Island have altitude that were only able to exceed the altitude of the equilibrium level and few were able to exceed the tropopause level of 9 km – 16 km. The difference in atmospheric conditions during extreme weather events on Java Island, which is in the tropics and subtropics, is a strong and unstable convective energy condition characterized by a larger CAPE, as well as unstable KI, LI, SI and TTI values. It is offset by kinematic factors in the form of a weak vertical wind shear (bulk wind shear 0-6 km) and a higher freezing point height. The difference between extreme weather events in the Java Island region and other tropical regions compared to subtropical regions is the strong updraft speed of convection clouds. The IRW Texture COMB algorithm based on the IRW-Texture Gradient modification and the COMB algorithm shows a significant increase in quality for detecting OT and non-OT pixels in Java. Rainy days with rainfall > 50 mm/day are very common in areas with an altitude of > 500 m. On the other hand, the level of convection activity which is indicated by the presence of OT and lightning is significantly reduced in this area. OT of convective clouds appear more frequently during the DJF season and less frequently during the JJA season. OT often appears during the day time and rarely at night time. Most OTs appear in the central part, away from the south and north coasts of Java Island during the day, while OTs that appear near the south and north coasts of Java Island can appear in the morning or afternoon.
Keyword: convective clouds, extreme weather, Overshooting Tops, Himawari 8 Satellite