Judul: Mempelajari pemanfaatan pulp kopi untuk memproduksi enzim pektinase dengan menggunakan aspergillus nuger pada fermentasi media padat
Abstrak: Pulp kopi yang selama ini belum dimanfaatkan merupakan hasil samping terbesar dalam industri pengolahan kopi. Dilihat dari komposisinya, pulp kopi masih mempunyai kandungan nutrisi yang mencukupi untuk pertumbuhan mikroba. Pemanfaatan pulp kopi sebagai media untuk memproduksi enzim pektinase merupakan salah satu alternatif penanggulangan masalah limbah. Penelitian ini bertujuan untuk mempelajari pemanfaatan pulp kopi sebagai media bagi Aspergillus niger guna mempro- duksi enzim pektinase, dengan penambahan urea sebagai sumber nitrogen dan pengaturan waktu inkubasi yang optimal untuk memproduksi enzim dengan aktifitas tertinggi. Dari hasil penelitian diketahui bahwa penambahan urea memberikan pengaruh yang sangat nyata terhadap peningkatan aktifitas enzim pektinase yang dihasilkan. Penambahan urea pada taraf satu persen (w/w) meningkatkan aktifitas enzim pektinase. Penambahan urea pada taraf yang lebih tinggi dari pada satu persen tidak lagi menaikkan aktifitas enzim pektinase, bahkan cenderung menurunkannya. ...
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Judul: Isolasi dan karakterisasi pektinase dari galur induk dan hasil mutasi aspergillus niger pada media cair kulit buah kopi
Abstrak: Pektinase merupakan enzim ekstraseluler yang mampu mendegradasi senyawa makromolekul pektin. Enzim ini dimanfaaatkan dalam industri jus buah dan sayuran, industri kembang gula, pengawetan kayu komersial dan dalam pengolahan kopi sebagai bahan penghilang lendir buah kopi. Produksi pektinase komersial umumnya menggunakan Aspergillus niger karena jenis kapang ini termasuk golongan GRAS (Generally Recognized As Safe). Hasil beberapa penelitian menunjukan bahwa A. niger merupakan penghasil pektinase yang potensial. Pektinase digolongkan menjadi dua kelompok besar, yaitu depolimerase dan pektinesterase. Depolimerase melakukan depolimerisasi dengan menguraikan ikatan a-1,4 senyawa pektin, dan secara umum dibedakan menurut jenis substrat (asam pektat, pektin atau oligo-D- galakturonat), jenis reaksi pemecahan (transeliminasi atau hidrolisa) dan pola degradasi (endo atau ekso). ...
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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