Judul: Pencirian bakteri penghasil protease yang diisolasi  dari limbah cair tahu dengan bantuan pulsed-field gel electrophoresis
Abstrak: Tiga isolat bakteri penghasil protease yaitu Y1, Y2 dan Y3 telah berhasil diisolasi dari limbah cair tahu. Ketiga isolat tersebut tumbuh dengan baik pada media Nutrient Agar dan media yang mengandung 150 mg/l siklohek- simid, tetapi tidak tumbuh pada media yang mengandung 20 mg/ml eritromisin. Identifikasi genus bakteri berda- sarkan Bergey's Manual of Determinative Bacteriology, edisi ke-8 (1974) menunjukkan bahwa ketiga isolat termasuk dalam genus Bacillus yang resisten terhadap 50 µg/ml ampisilin. Identifikasi spesies bakteri menunjukkan bahwa ketiga bakteri adalah Bacillus pumilus. Pulsed-Field Gel Electrophoresis (PFGE) digunakan untuk melakukan pencirian sidik jari DNA menggunakan enzim restriksi BglI, Xhol dan Apal. Analisis PFGE menunjukkan bahwa skisotipe bakteri Y3 sama dengan skisotipe B. pumilus sedangkan skisotipe bakteri Y₁ identik dengan skisotipe Y2 tetapi berbeda dengan skisotipe B. pumilus. Hasil penelitian ini menun- jukkan bahwa analisis sidik jari DNA dengan PFGE dapat membedakan galur B. pumilus yang morfologi dan fisiologi- nya nampak sama.
Keyword: 

Judul: Karakterisasi protease Bacillus pumilus Y3 yang dilisolasi dari limbah cair tahu
Abstrak: Penelitian ini bertujuan untuk mempelajari karak- terisasi protease Bacillus pumilus Y3 yang diisolasi dari limbah cair tahu (Likumahwa 1993). Media yang digunakan untuk produksi protease dari mikroba ini adalah limbah cair tahu dengan penambahan glukosa sebesar 1% dan suhu optimum pertumbuhan 37°C Aktivitas protease dari Bacillus pumilus Y3 memiliki suhu optimum 50°C dengan pH optimum 7.50 dan kecenderungan memperlihatkan kestabilan pada PH alkalis. Berdasarkan karakteristik pH-nya diduga protease Bacillus pumilus Y3 merupakan protease alkalis. Penambahan logam monovalen (KCl, NaCl, LiCl sebesar 2mM dan 6mM) dan logam divalen (CaCl2, ZnCl2, MnCl2, COC12 sebesar 2 mM) memperlihatkan aktivitas optimum terlihat pada logam divalen yaitu logam MnCl2 dan CaCl2 2mM memperlihatkan kenaikan aktivitas sebesar 176.17% dan 229.19% dibandingkan kontrol. Berdasarkan karakterisasi keterpengaruhan terhadap logam-logam ini diduga bahwa protease Bacillus pumilus Y3 merupakan protease logam. Protease Bacillus pumilus Y3 dapat dihambat oleh penambahan PMSF 1 dan 5 mM, penambahan EDTA 6mM mengalami penurunan aktivitasnya sampai 5.6%. Berdasarkan karakterisasinya diduga protease Bacillus pumilus Y3 termasuk kedalam protease serin metal. ...
Keyword: 

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