Judul: Penapisan bakteri pendegradasi propionamida dan karakterisasi enzim amidase dari isolat terpilih
Abstrak: Aril propionat dan turunannya merupakan obat kiral yang termasuk dalam kelompok obat antiinflamasi non-steroid (AINS). Senyawa AINS secara prinsip dapat dihasilkan melalui biotransformasi nitril atau amida secara enansioselektif yang melibatkan enzim nitrilase, nitril hidratase dan amidase. Penelitian ini bertujuan mendapatkan isolat bakteri yang mampu menghasilkan amidase dan melakukan karakterisasi amidase dari isolat terpilih. Isolat GLB5 merupakan isolat terpilih yang memiliki pertumbuhan dan aktivitas tertinggi pada propionamida. GLB5 memiliki waktu generasi (td) dan konstanta laju pertumbuhan (μ) masing-masing sebesar 73 jam dan 9.5 x 10-3 jam -1. Suhu dan pH optimum amidase dari sel GLB5 adalah 45 °C dan 7. Parameter kinetik KM dan Vmaks amidase adalah 45.32 mM dan 2.74 mmol/mL min. Aktivitas amidase ditingkatkan oleh Mn2+, Co2+, Ni2+, Mg2+ dan Fe2+ dan dihambat oleh Hg2+, Cu2+, Zn2+ dan Ca2+. Amidase menunjukkan aktivitas yang lebih tinggi pada amida alifatik berbobot molekul rendah. Stabilitas enzim tertinggi berada pada suhu penyimpanan -4 ºC dengan waktu paro 10 hari. Konsentrasi asam propionat yang terbentuk setelah reaksi berjalan 30 menit adalah 68.76 ppm.
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Judul: Identifikasi Bakteri Proteolitik Asal Danau Gili Meno dan Karakterisasi Protease Hasil Pengendapan dengan Amonium Sulfat
Abstrak: Indonesia merupakan negara tropis yang dikenal memiliki keanekaragaman hayati yang besar. Salah satu di antaranya bakteri indigenous penghasil enzim protease. Penelitian sebelumnya melaporkan bahwa isolat LG 18 dan LI 2 asal Danau Gili Meno, Nusa Tenggara Barat merupakan bakteri proteolitik yang mampu menghasilkan enzim protease. Penelitian ini bertujuan mengidentifikasi bakteri proteolitik isolat LG 18 dan LI 2, mengetahui konsentrasi optimum penambahan amonium sulfat pada enzim ekstrak kasar serta mengarakterisasinya. Isolat LG 18 dan LI 2 merupakan bakteri Gram positif dengan bentuk sel batang. Berdasarkan hasil identifikasi secara fisiologis menggunakan kit Analytical Profile Index (API) 50 CHB/E isolat bakteri LG 18 diduga Brevibacillus laterosporus dan LI 2 diduga Bacillus mycoides. Berdasarkan identifikasi molekuler gen 16S rRNA kedua isolat tersebut adalah Bacillus cereus. Enzim ekstrak kasar isolat LG 18 dan LI 2 yang diendapkan dengan amonium sulfat memiliki aktivitas spesifik tertinggi masing-masing sebesar 0.0592 U/mg (25% b/v) dan 0.0785 U/mg (40% b/v). Protease semimurni kedua isolat optimum pada suhu 30°C. Protease semimurni isolat LG 18 optimum pada pH 5 dan LI 2 pada pH 8.
Keyword: Aktivitas spesifik, bakteri proteolitik, enzim ekstrak kasar, protease, purifikasi.

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