Judul: Studi produksi protease Bacillus subtilis DB104 rekombinan R-1 dalam fermentasi terkontrol menggunakan media semi sintetik
Abstrak: Bacillus subtilis DB104 rekombinan R-1 merupakan salah satu strain bakteri proteolitik hasil kloning gen protease B. pumilus Y1 ke dalam B. subtilis DB104, menggunakan plasmid vektor pUB110 dengan metode fusi protoplas (Koswara, 1999). B. pumilus Y1, sebagai donor gen protease, merupakan galur lokal dari Bacillus sp. yang diisolasi dari limbah cair tahu (LCT) oleh Suhartono et al. (1994). B. pumilus Y1 memproduksi protease ekstraseluler dengan BM sekitar 30 kD, pH optimum 8.0 dan suhu optimum 55°C. Sementara itu, protease B. subtilis DB104 rekombinan mempunyai BM sekitar 59.5 kD dan terdiri dari dua sub unit dengan BM sekitar 29 kD. Suhu optimumnya 60°C dengan pH optimum 6.5 - 9.0. Seperti protease B. pumilus Y1, PMSF (Phenyl Methyl Sulphonyl Fluoride) menghambat aktivitas bakteri rekombinan secara nyata. Kloning gen protease mampu meningkatkan aktivitas spesifik protease B. pumilus Y1 sebesar 3 kali lipat pada media LCT + skim 0.5% atau 6 kali lipat pada media LB (Luria Broth) + skim 0.5%. Penggunaan kultur mikroba potensial penghasil protease, proses seleksi dan optimasi komposisi media fermentasi serta pengontrolan kondisi pertumbuhan menggunakan bioreaktor, diharapkan mampu meningkatkan produktivitas protease bakteri rekombinan R-1 secara maksimal sehingga cukup kompetitif untuk diproduksi secara komersial. Penelitian ini bertujuan untuk mempelajari produksi protease dari B. subtilis DB104 rekombinan R-1 dalam fermentasi terkontrol menggunakan beberapa media semi sintetik. Secara umum, penelitian ini terbagi menjadi dua tahap. Tahap pertama merupakan tahap penentuan media semi sintetik terbaik bagi produksi protease. Tahap kedua merupakan tahap produksi protease menggunakan bioreaktor dan optimasi hasil dengan teknik imobilisasi enzim. ...
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Judul: Studi Produksi Enzim Protease Bacillus subtilis DB 104 Rekombinan R-l Pada Media Tepung Kedelai
Abstrak: Enzim Protease merupakan biokatalisator yang berasal dari mikroba dan memiliki beberapa kelebihan dibandingkan dengan enzim produk non mikrobial. Kelebihan produk mukrobial antara lain dapat diproduksi dalam skala besar dan produksinya mudah ditingkatkan. Hal yang harus diperhatikan dalam produksi enzim protease dari mikroba adalah seleksi galur dan pemilihan kondisi lingkungan (baik fisik maupuu kimia). Kegunaan dan pangsa pasar yang luas baik dalam industri pangan maupun non pangan mendorong para ilmuwan mengembangkan penelitian yang berkaitan dengan enzim tersebut.
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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