Judul: Kinetika biotransformasi suksinonitril menjadi asam suksinat oleh Pseudomonas sp.
Abstrak: Asam suksinat (HOOC(CH2)2COOH) merupakan senyawa komersial yang banyak digunakan dalam bidang pangan, misalnya pada industri kecap, sari buah, anggur, dan produk-produk susu lainnya. Selama ini asam suksinat yang kita gunakan dihasilkan melalui serangkaian reaksi kimia yang sangat berbahaya sehingga diperlukan alternatif baru yang lebih aman dan murah melalui proses biotransformasi dengan memanfaatkan aktivitas Pseudomonas sp. Untuk mengetahui kemampuan Pseudomonas sp. dalam proses biotransformasi digunakan sistem fermentasi batch untuk menentukan pola pertumbuhan, perubahan pH, produksi amonium, laju penguraian substrat, dan pembentukan produk. Analisis terhadap penguraian suksinonitril dan asam suksinat yang terbentuk menggunakan kromatografi cair kinerja tinggi yang menggunakan metanol 80% sebagai fase gerak, fase diam kolom organik C18 10 , dan detektor ultraviolet yang diukur pada panjang gelombang 220 nm, sedangkan amonium yang terbentuk diukur dengan menggunakan spektrofotometer pada panjang gelombang 400 nm. Hasil penelitian menunjukkan produksi optimum enzim terjadi pada fasa log. Laju pembentukan asam suksinat sebesar 0.982 mM/mL.jam seiring dengan penurunan konsumsi substrat sebesar 1.235 mM/mL.jam. Perolehan asam suksinat setelah 81 jam fermentasi sebesar 81 %. pH optimum, temperatur optimum, Km, dan Vmaks adalah 7, 27 °C, 90 mM, dan 0.0002 µM/mL.jam.
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Judul: Biokonversi Adiponitril Menjadi Asam Adipat Oleh Isolat Bakteri Terpilih
Abstrak: bahan yang sangat penting basil dari indllstri poliamida. Nilen 6,6 banyak digunakan sebagai kain, film, resin. dan monofilamen. Selain itu, heksametilendiamina yang juga digunakan sebagai bahan untuk memsintesis nilon 6,6 dapat disintesis dari asam adipat. Sintesis asam adipat secara kimiawi membutuhkan konsentrasi asam dan energi yang tinggi. Proses biokonvcrsi hadir untuk mengatasi kendala tersebut Dalam pene1itian ini dilakukan seleksi iso1at bakteri sebagai pengkonversi adiponitril menjadi asam adipat, nji pengaruh peningkatan konsentrasi substtat terhadap pertumbuh"m isolat bakteri terseleksi. pala pertumbuhan isolat bakteri terseleksi pada media pertumbuhan, dm analisis hasil degradasi adiponitril oleh isolat bakteri terse1eksi. Dari basil seleksi yang dilakukan terhadap beberapa isolat bakteri diperoleh isolat bakteri BAl sebagai isolat bakteri yang mempunyai tingkat pertumbuhan terbaik. Substrat terbaik yang digunakan adalah campuran adiponitril dan asetonitril dengan kosentrasi optimum masing-masing sebesar 120 mM dan 30 mM. Pertumbuhan isolat bakteri BA2 pada campuran adiponitril 120 mM dan asetonitril 30 mM mengalami fase adaptasi selama 168 jam sedangkan fase stasioner barn tercapai setelah 172 jam. Aktivitas degradasi adiponitril tertinggi teJjadi
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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