Judul: Analisis aktivitas siklodekstrin glukanotransferasi dan sintesis polifenol-@ glikosida secara enzimatik
Abstrak: Senyawa polifenol-a-glikosida telah dimanfaatkan sebagai agen yang efektif pada proses-proses biologi. Sintesis senyawa polifenol-a-glikosida dengan menggunakan enzim siklodekstrin glukano- transferase (CGTase) belum diteliti secara eksploratif. Polifenol-a-glikosida dapat disintesis oleh CGTase dengan menggunakan akseptor senyawa polifenol. Dalam penelitian ini dilakukan analisis terhadap aktivitas CGTase lima biakan yang disolasi dari kacang kedelai steril yang difermentasi secara alami dengan jerami padi yang masih segar, yaitu JI₂, JII, JIMI₂, JIII, dan JIII,, dan sintesis polifenol-a-glikosida. Pengujian aktivitas CGTase menggunakan metode Masataka et al. (1993), sintesis dan pemisahan produk transfer dengan menggunakan metode Sulistyo et al. (1994). Pengujian gula total pada tiap fraksi hasil elusi dengan kolom arang aktif dianalisis dengan menggunakan metode Dubois (1956). Kelima biakan yang diisolasi dari jerami yang mengandung kacang kedelai menunjukkan aktivitas CGTase, tetapi hanya isolat JI₂, JII, dan III, yang menunjukkan aktivitas transfer pada akseptor hidrokinon, resolsinol dan piroketekol. Hasil identifikasi sampai tingkat spesies menunjukkan bahwa isolat JI, adalah Bacillus subtilis dan isolat JII, adalah Bacillus megaterium, sedangkan isolat JII, hanya teridentifikasi sampai tingkat genus yaitu Bacillus. Hasil pemisahan dengan kolom arang aktif, menunjukkan bahwa produk transfer terelusi ke luar pada etanol 10%. Produk transfer yang dibentuk dari 2.5 gr pati dan 1gr hidrokinon sebesar 0.74 mg (0.03%). Produk transfer yang diinginkan belum murni, karena masih tercampur beberapa senyawa turunan anilin lainnya dengan berat molekul yang lebih kecil. Oleh karena itu fraksi yang mengandung produk transfer masih perlu dimurnikan lebih lanjut.
Keyword: Siklodekstrin

Judul: Eksplorasi sejumlah isolat Bacillus sp. lokal penghasil siklodekstrin glikosil transfererase pada substrat pati singkong
Abstrak: Siklodekstrin mempunyai kemampuan membentuk senyawa kompleks inklusi sehingga menghasilkan perubahan sifat fisik seperti meningkatkan kelarutan senyawa organik, tahan terhadap kerusakan kimia dan biokimia (enzim dan mikroorganisme), dan dapat menstabilkan senyawa flavor. Selain itu, siklodekstrin mempunyai kemampuan membentuk senyawa kompleks inklusi sehingga menghasilkan perubahan sifat fisik seperti meningkatkan kelarutan senyawa organik, tahan terhadap kerusakan kimia dan biokimia (enzim dan mikroorganisme), dan dapat menstabilkan senyawa flavor. Adanya sifat tersebut di atas menyebabkan siklodekstrin banyak digunakan untuk keperluan industri pangan, kosmetika, farmasi dan kimia (Lee dan Kim, 1991).
Keyword: Siklodekstrin, CGTase, Manihot utilissima

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