Judul: Isolasi dan Kloning Gen Penyandi Fitase dari Bacillus subtilis AQ1 dengan Teknologi Gateway
Abstrak: Fitase merupakan enzim yang dapat mengkatalisis reaksi pemecahan asam fitat untuk membebaskan fosfor dan nutrien yang terdapat dalam kompleks fitat sehingga dapat mengurangi efek antinutrisi dari asam fitat. Enzim ini sangat penting sebagai bahan tambahan pakan ternak monogastrik. Teknik rekayasa genetika diperlukan untuk menghasilkan DNA rekombinan penyandi gen fitase yang lebih stabil dengan produktivitas yang tinggi. Gen phy diisolasi dari bakteri Bacillus subtilis AQ1 yang telah terbukti menghasilkan fitase. Penelitian ini bertujuan menyisipkan gen penyandi fitase pada vektor donor dan vektor ekspresi dengan teknik kloning Gateway. Gen phy hasil kloning ditransformasikan ke dalam E.coli BL21-Star. Ekspresi fitase rekombinan dalam E.coli BL21-Star dapat terlihat dari hasil uji aktivitas fitase pada jam ke-6, ke-12, dan ke-24 yang masing-masing memiliki aktivitas sebesar 1.989 U/mL, 2.988 U/mL, dan 3.331 U/mL. Hasil aktivitas ini menunjukkan bahwa gen fitase yang dikloning dengan metode Gateway dapat terekspresi dalam E.coli BL21-Star.
Keyword: Fitase, asam fitat, Bacillus subtilis AQ1, kloning Gateway

Judul: Telaah pengklonan gen protease dari Bacillus stearo thermophilus ke dalam Escherichia coli
Abstrak: Fragmen-fragmen genom dari Bacillus stearothermophilus, yang dipotong secara parsial dengan Eco RI atau HindIII, telah diklon dalam Escherichia coli dengan teknik shot gun cloning menggunakan plasmid pRK415 sebagai vektornya untuk gen protease. Media agar MacConkey (Jennings dan Beacham, 1989) dengan sedikit modifikasi dipakai untuk deteksi koloni pembawa plasmid rekombinan atau plasmid nonrekombinan. Media tersebut terdiri dari 10 g tripton, 5 g ekstrak kha­ mir, 10 g laktose, 0.075 g neutral red, 15 g agar dalam 1 L dH20, pH diatur pada 7 .4. Untuk deteksi ekspresi gen protease, media tersebut ditambahkan 2 % susu skim. Media ini dinamakan SMMCA (skim milk modified MacConkey agar). Penghilangan kristal violet, garam empedu dan garam memberikan hasil yang baik untuk deteksi koloni-koloni tersebut. Sel koinpeten untuk keperluan pengklonan disiapkan dengan metode miniprep, sesuai prosedur Lederberg dan Cohen (1974) dengan sedikit modifikasi, dilakukan dengan cara mensentrifusi 1.5 mL kultur fase log dalam tabung mikro setelah sebe­lumnya diinkubasikan selama 30 menit pada 0°C. Pelet sel dicuci dengan 1 mL 0.1 M CaC12 dingin, kemudian sel disuspensikan dalam 0.5 mL 0.1 M CaC12 dingin dan diinkubasikan pada 0°C selama 20 menit, sentrifusi terakhir dilakukan dan pelet sel disuspensikan dalam 0.2 mL 0.1 M CaC12 dingin, pada kondisi ini sel siap digu­ nakan untuk transformasi. Isolasi DNA kromosom dengan metode Marmur (1961) mendapatkan DNA dengan kualitas yang cukup baik, dan dapat dipakai untuk keperluan kloning, walauiv pun dilakukan tidak sampai pada tahap pemurnian lanjutan seperti penghilangan RNA dan pemekatan. Dari 500 mL kultur fase log diperoleh lebih kurang 2 mg DNA kromosom. ...
Keyword: Escherichiacoli, Proteinase

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