Judul: Mempelajari pengaruh konsentrasi gula (sukrosa) terhadap produksi alginat yang dihasilkan oleh bakteri Pseudomonas aeruginosa
Abstrak: Penelitian ini bertujuan untuk mempelajari pengaruh konsentrasi gula (sukrosa) dan lama inkubasi terhadap produksi alginat yang dihasilkan oleh Pseudomonas aeruginosa. Penelitian ini terdiri atas 2 tahap. Tahap pertama menentukan metoda penyimpanan bakteri dan tahap kedua proses produksi sel yang terdiri dari persiapan bahan, proses fermentasi dan pemanenan. Pengamatan kultur dilakukan setelah kultur berumur 3, 5, 7, 9, 11, 13, 15, 18, 22, 26, 30, 36, 42, 48, 72, dan 96.jam. Parameter yang diukur untuk setiap kali pengamatan adalah konsentrasi alginat, massa sel kering, persentase jumlah sel mucoid dan nonmucoid, residu gula, pH akhir. Selain itu diukur efisiensi konversi nutrien menjadi alginat (Yp/s) dan biomassa (Yx/s) serta efisiensi konversi alginat per biomassa total (Yp/x) dan per biomassa mucoid (Yp/x+) dari kultur. Dari hasil analisa selama inkubasi pada kultur cair, pada medium A (10 g/l), konsentrasi alginat berkisar 0.32-0.85 g/l, massa sel kering berkisar 0.60 -1.57 g/l, persentase jumlah sel mucoid berkisar 10,00-57.14% dan nonmucoid berkisar 42.86 90.00%, residu gula berkisar 2.487.47 g/l, pH akhir berkisar 7-8, nilai Yp/s berkisar 0.0790.857 g produk/g substrat, nilai Yx/s berkisar 0.1942.071 g biomassa/g substrat, nilai Yp/x berkisar 0.112 - 1.164 g produk/g biomassa, dan nilai Yp/x+ berkisar 0.2693.890 g produk/g biomassa. ...
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Judul: Mempelajari pengaruh konsentrasi ekstrak kamir terhadap produksi alginat yang dihasilkan oleh bakteri Pseudomonas aeruginosa
Abstrak: Alginat dihasilkan dari rumput laut. Rumput laut penghasil alginat komersial tidak dapat tumbuh di Indone- sia. Alginat dimanfaatkan pada sektor pangan maupun non- pangan. Pemanfaatan alginat umumnya sebagai penstabil, pengemulsi dan pengikat air. Dengan kemajuan ilmu bioteknologi, alginat dapat dihasilkan dari mikroba. Jarman et al (1978) melaporkan bahwa Bakteri Psaeudomonas aeruginosa dan beberapa galur Azotobacter vinelandii dapat menghasilkan alginat yang sama baiknya dengan alginat dari rumput laut. Penelitian ini bertujuan untuk mempelajari pengaruh konsentrasi ekstrak khamir dan lama inkubasi terhadap produksi alginat yang dihasilkan oleh bakteri Pseudomonas aeruginosa Penelitian ini dilaksanakan di Laboraturium Fermen- tasi, Pusat Antar Universitas (PAU) Bioteknologi, Institut Teknologi Bandung (ITB). Penelitian ini terdiri atas 2 tahap. Tahap pertama menentukan metode penyimpanan bakteri dan tahap kedua proses produksi alginat yang terdiri dari persiapan bahan, proses fermentasi dan pemanenan. ...
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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