Judul: Protease Activity of Bacillus circulans in Various Level of Purification
Abstrak: Bekatul mempunyai potensi yang sangat besar untuk dimanfaatkan selain harganya murah juga kualitasnya sebagai bahan makanan cukup tinggi. Hal ini disebabkan pada bekatul terkandung asam- asam amino esensial. Bekatul juga memiliki kandungan lemak yang cukup tinggi. Oleh karena itu bekatul mudah tengik dalam penyimpanan karena lipase dapat memecah lemak menjadi asam-asam lemak. Salah satu upaya memperkecil aktivitas lipase adalah dengan menggunakan enzim antilipase. Enzim ini tergolong protease. Protease dapat ditingkatkan aktivitasnya melalui pemurnian. Pemurnian dilakukan dengan memisalıkan enzim tertentu dari ekstrak enzim kasar yang masih mengandung sel mikroba dan komponen lainnya. Pada penelitian ini dilakukan tahap pemurnian sebagai berikut: produksi enzim kasar, pengendapan pada konsentrasi garam ammonium sulfat tertentu yang dikenal dengan salting out, dialisis, dan freeze drying. Pada penelitian ini isolat bakteri yang digunakan untuk produksi protease adalah Bacillus circulans. Air rendaman kedelai dengan pH tidak terkontrol digunakan sebagai media produksi protease. Kadar protein diukur menggunakan metode Bradford (1976) sedangkan aktivitas protease ditentukan dengan inetode Grassl dan Bergmeyer (1983). Tingkat kemurnian enzim ditentukan berdasarkan aktivitas spesifik (U/mg). Produksi protease dilakukan selama 56 jam dan optimum pada pH 9.28. Kondisi ini tercapai pada fase akhir eksponensial dari fase pertumbuhan bakteri. Pemurnian ternyata dapat meningkatkan aktivitas protease. Pada tahap dialisis kemurnian enzim mencapai 5,37 kali dan aktivitas spesifik 1.3359 U/mg. sedangkan kemurnian pada tahap freeze drving sebesar 5.90 kali dan aktivitas spesifik sebesar 1,4666 U/mg.
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Judul: Pemurnian dan Optimasi Protease dari Bacillus circulans Strain 9b3
Abstrak: Protease yang diisolasi dari isolat B. circuians adalah protease yang secara spesifik mampu menghidrolisis struktur protein lipase yang terdapat dalam bekatul, sehingga terjadi penghambatan aktivitas katalitik lipase. Penghambatan aktivitas katalitik lipase ini dipedukan karena lipase mempereepat proses ketengikan pada bekatul, sedangkan bekatul memiliki potensi yang besar untuk dimanfaatkan, disamping harganya mural!, juga kualitasnya sebagai bahan makanan eukup tinggi. Pada penelitian ini dicari media pertumbuhan dan waktu inkubasi optimum dari B. cireuians dengan menggunakan dua macam media, yaitu media air rendaman kedelai dan media air rebusan kedelai. Protease yang diperoleh dimumikan dengan earn pengendapan dengan (NH.,),S04 70% dan dialisis, masing-masing fraksi diuji aktivitas dan aktivitas spesifiknya, ditentukan pula kondisi optimum kelja enzim yang meliputi pH, suhu dan waktu inkubasi.
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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