Judul: Screening Awal Enzim Endonuklease Restriksi Spesifik dari Bakteri
Abstrak: Enzim endonuklease restriksi tipe II adalah enzim yang mampu mengenali dan memotong sekuens nukleotida tertentu. Kerja enzim yang spesifik ini berperan penting dalam perkembangan bioteknologi, termasuk di dalamnya bioteknologi pangan yang telah memberikan hasil nyata, seperti varietas pangan yang dimodifikasi secara genetik. Enzim ini dihasilkan oleh setiap bakteri yang tersebar luas di alam, dan dalam penelitian ini isolat bakteri tongkol jagung diteliti potensinya dalam menghasilkan enzim restriksi. Penelitian bertujuan untuk screening keberadaan enzim restriksi yang memiliki situs spesifik. Penelitian dimulai dengan screening bakteri dari tongkol jagung busuk. Dari 16 macam isolat bakteri mesofilik, diambil 10 macam isolat kemudian masing-masing isolat ditumbuhkan untuk kemudian diambil pelet selnya dan diekstrak enzim restriksinya. Selain bakteri isolat tongkol jagung, juga diambil ekstrak enzim dari beberapa bakteri koleksi Laboratorium Mikrobiologi dan Biokimia, yaitu Bacillus pumillus Y1, B. licheniformis MB2, Pseudomonas syringae, P. fluorescens, dan beberapa strain dari Xanthomonas axonopodis pv. glycines (Xag R8, Xag YR58, Xag YR63, dan Xag YR69). Tahap ekstraksi enzim restriksi meliputi pemecahan sel bakteri dan ekstraksi enzim dengan metode sistem dua fase. Pemecahan sel menggunakan metode sonikasi diskontinu (4 dan 6 × 30 detik). Ekstraksi enzim dua fase menggunakan polimer PEG 8000 28,4% dan dekstran T500 7,1% yang akan memisahkan enzim resktriksi dari asam nukleat bakteri.
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Judul: Screening Enzim Endonuklease Restriksi Dari Bakteri Asal Indonesia
Abstrak: Enzim endonuklease restriksi adalah enzim yang dapat mengenali dan memotong kedua utas DNA (Deoxy Ribonucleic Acid) pada urutan basa tertentu. Enzim ini memiliki peranan penting dalam berbagai teknik molekuler dan genetika, misalnya untuk analisis gen dan kloning gen yang bermanfaat. Bidang ilmu dan teknologi pangan memanfaatkan enzim ini, misalnya dalam mendeteksi patogen pangan secara molekuler. Enzim ini juga bermanfaat untuk pengembangan produk-produk pertanian, seperti varietas kedelai tahan hama, kentang tahan virus, analisis gen, dan konstruksi pangan transgenik. Enzim endonuklease restriksi dihasilkan oleh bakteri yang tersebar di alam dan penelitian ini bertujuan memilah enzim endonuklease restriksi dari bakteri-bakteri isolat koleksi Laboratorium Mikrobiologi dan Biokimia Pusat Penelitian Sumberdaya Hayati dan Bioteknologi IPB. Penelitian dimulai dengan pemilihan isolat bakteri sebanyak 11 isolat yang dianggap berpotensi menghasilkan enzim restriksi berdasarkan referensi yang diperoleh dari penelitian sebelumnya. Sebelas isolat tersebut berasal dari genus Rhodobacter, Pseudomonas, Bacillus dan beberapa isolat bakteri asal tongkol jagung. Isolat tersebut ditumbuhkan sehingga diperoleh pelet sel yang akan digunakan untuk ekstraksi enzim. Selain produksi enzim, isolasi DNA plasmid pUC 19 dilakukan untuk memperoleh substrat bagi enzim. Plasmid pUC 19 diperoleh dari E.coli carrier plasmid pUC 19. Metode yang digunakan untuk isolasi plasmid adalah metode lisis alkali.
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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