Judul: Optimasi dan Komposisi Mikroba dan Substrat dalam Produksi Amilase dan Akumulasi Lipid
Abstrak: Amilase adalah enzim yang dapat memecah polisakarida menjadi gula-gula sederhana. Mikroba yang berperan menghasilkan amilase pada penelitian ini yaitu Aspergillus niger, Saccharomyces sp., dan Candida sp.. Substrat yang digunakan untuk menghasilkan amilase yaitu yang mengandung pati atau amilum seperti beras, gabah, tepung singkong, dan limbah tapioka. Penelitian ini bertujuan menentukan formulasi mikroba dan substrat yang paling efektif dalam produksi amilase dan menentukan keadaan optimum mikroba dalam mengakumulasi lipid sebagai bahan baku biodiesel. Aktivitas amilase diukur dengan metode dinitro salisilat (DNS), sedangkan akumulasi lipid menggunakan metode sudan hitam. Hasil menunjukkan bahwa Aspergillus niger dan limbah tapioka masing-masing merupakan mikroba dan substrat yang paling efektif dalam aktivitas amilase sebesar 110.2 U, optimum pada suhu 30˚C dan pH 7 serta pada waktu inkubasi 3 hari. Aspergillus niger juga merupakan mikroba oleaginous yang dapat mengakumulasi lipid sebesar 67.83% dari total berat keringnya dengan substrat limbah tapioka dan efektif pada hari ke-10 waktu inkubasi.
Keyword: amylase, microbes, Aspergillus niger, tapioca waste

Judul: Optimasi Kondisi Produksi Enzim α-Amilase dari Bacillus licheniformis dengan Metode Fermentasi Padat pada Substrat Limbah Dedak Padi.
Abstrak: Enzim amilase merupakan kelompok enzim yang sangat dibutuhkan dalam bidang industri dan produksi komersialnya dari mikroorganisme mencapai 25%- 33% dari pasaran enzim di dunia. Tujuan penelitian ini mendapatkan kondisi optimum produksi α-amilase berdasarkan aktivitas ekstrak kasar enzim amilase dari bakteri Bacillus licheniformis dengan metode fermentasi substrat padat menggunakan limbah pertanian dedak padi. Optimasi dilakukan dengan berbagai parameter seperti waktu produksi (fermentasi), konsentrasi substrat, pH produksi, suhu fermentasi, dan ko-substrat. Pengukuran aktivitas amilase menggunakan metode DNS dan diukur absorbansinya menggunakan spektrofotometri pada panjang gelombang 540 nm. Produksi enzim α-amilase maksimum didapatkan pada waktu fermentasi selama 36 jam, dengan penambahan substrat dedak padi pada konsentrasi 50 g/L, pada kondisi pH 8, suhu 370C, maltosa sebagai kosubstrat dengan konsentrasi 1.5%.
Keyword: Amylase activity, Bacillus licheniformis, Optimization

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