Judul: Peranan bakteri asal pencernaan ikan nila gift dalam menghambat pertumbuhan Microcystis aeruginosa BT-02
Abstrak: Penelitian ini bertujuan untuk menapis bakteri proteolitik yang berasal dari saluran pencemaan ikan Nila GIFT yang memiliki kemampuan untuk menghambat pertumbuhan sianobakter Microcystis aeruginosa BT-02. M. aeruginosa merupakan sianobakter yang dapat menyebabkan blooming yang bersifat toksik terutama pada ikan. Dipilih empat isolat proteolitik yang memilii indeks protease tertinggi, yaitu NU-2, NU-3, NU-4, dan NU-8. Kultur M aeruginosa ditumbuhkan pada dua macam media cair, yaitu BG-11 termodifikasi dan MLA. Metode agar-agar blok lapis ganda (Double layer) digunakan untuk menapis M. aeruginosa. Isolai NU-4 dan NU-8 dapat mendegradasi koloni M. aeruginosa BT-02. Indeks penghambatan sebesar 1.6 dihasilkan oleh NU-8 yang lebih besar daripada NU-4 dengan nilai 1.3. Ekstrak kasar protease yang dihasilkan kedua isolat tersebut tidak dapat menghambat pertumbuhan M. aeruginosa BT-22. Kedua isolat bakteri tersebut termasuk bakteri Gram negatif dan NU-8 diidentifikasi sebagai Aeromonas
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Judul: Karakterisasi a-amilase dan glukoamilase dari bakteri proteolitik asal, pencernaan ikan nila gift
Abstrak: Penggunaan teknologi probiotik telah menjadi salah satu alternatif dalam usaha meningkatkan produktivitas perikanan. Penelitian ini bertujuan untuk menapis isolat amilolitik yang memiliki aktivitas a-amilase dan glukoamilase dari sejumlah bakteri proteolitik yang berasal dari saluran pencernaan ikan nila GIFT (Genetic Improvement of Farmed Tilapias). Dari 31 isolat bakteri proteolitik, berhasil ditapis sebanyak 18 isolat amilolitik. Tiga isolat diantaranya menunjukkan indeks amilolitik (IA) terbesar yaitu NU-1, NU-2, dan NL-15. Pengukwan aktivitas a-amilase menggunakan metode Bernfeld dan aktivitas glukoamilase dengan metode Somogyi-Nelson.
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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