Judul: In Silico and In Vitro Characterization and Production Optimization of Phytase Enzyme from Aspergillus niger IPB CC 93 0265
Abstrak: Asam fitat merupakan senyawa kimia yang terdiri dari inositol dan asam fosfat dan merupakan senyawa antinutrien yang terdapat pada bahan pakan unggas monogastrik yang terbuat dari tanaman serealia. Fitase merupakan enzim yang dapat menghidrolisis ikatan fosfoester pada asam fitat sehingga menghasilkan fosfat anorganik dan ester fosfat. Aspergillus merupakan salah satu genus kapang yang dapat menghasilkan fitase dan telah banyak digunakan dalam produksi fitase karena mudah dibudidayakan. A. niger, A. awamori dan A. ficuum merupakan tiga spesies Aspergillus yang menghasilkan fitase dengan struktur dan sifat fisikokimia yang paling sesuai untuk diaplikasikan pada pakan unggas serta memiliki tingkat homologi yang cukup tinggi. Penelitian terdahulu telah membuktikan bahwa kapang A. niger, A. ficuum dan A. awamori merupakan tiga spesies Aspergillus yang menghasilkan fitase dengan karakteristik fisikokimia serta struktur yang homolog dan cocok untuk diaplikasikan pada pakan secara in silico. Namun, belum dilakukan penelitian mengenai perbandingan penambatan molekuler enzim fitase dari ketiga kapang untuk menentukan spesies Aspergillus yang paling cocok. Tujuan dari penelitian ini adalah melakukan simulasi penambatan molekuler pada enzim fitase dari tiga spesies Aspergillus dengan kemiripan tertinggi serta mengoptimalkan kondisi produksi dan karakterisasi sederhana enzim fitase dari spesies Aspergillus yang mempunyai karakteristik terbaik hasil dari molekuler docking sebagai langkah pertama dalam produksi enzim fitase skala besar untuk diterapkan pada pakan unggas. Metode yang digunakan adalah pemodelan struktur dan penambatan molekuler in silico yang dikombinasikan dengan optimasi kondisi produksi secara in vitro meliputi pH, waktu inkubasi dan konsentrasi penginduksi fitase A. niger IPB CC 93 0265. Hasil docking ketiga struktur fitase menggunakan YASARA menunjukkan bahwa fitase 1QFX memiliki skor ΔG paling negatif dan skor Kd terkecil yang menunjukkan afinitas tertinggi terhadap substrat asam fitat. Fitase A. niger IPB CC 93 0265 mempunyai aktivitas spesifik tertinggi setelah produksi 4 hari dengan medium pH 7 dan induser fitat 0,5%. Kemurnian tertinggi diraih dari fraksi dialisis dengan aktivitas spesifik sebesar 0.18 U/µg, persentase yield sebesar 49.61% dan kemurnian meningkat sebesar 4.01 kali lipat dibandingkan ekstrak kasar. Nilai Km terukur 6.583 µmol serta vmaks sebesar 0.139 µmol/menit. Fitase A. niger IPB CC 93 0265 memiliki bobot molekul di rentang 25 – 37 KDa. Kesimpulan dari penelitian ini adalah diantara 3 struktur fitase yang telah dibandingkan dan di-docking dengan asam fitat, fitase 1QFX dari A. niger merupakan fitase yang paling sesuai untuk diaplikasikan pada pakan unggas setelah 4 hari produksi enzim dalam medium pH 7 dan konsentrasi fitat 0,5%., Phytic acid is a chemical compound consisting of inositol and phosphoric acid and is an antinutrient compound found in monogastric poultry feed ingredients made from cereal crops. Phytase is an enzyme that can hydrolyze phosphoester bonds in phytic acid, resulting in inorganic phosphate and phosphate esters. Aspergillus is a genus of mold that can produce phytase and has been widely used in the production of phytase because it is easily cultured. A. niger, A. awamori and A. ficuum are three Aspergillus species that produce phytase with the most suitable structure and physicochemical properties for application in poultry feed and have a fairly high level of homology. Previous research has proven that A. niger, A. ficuum and A. awamori are three Aspergillus
Keyword: Enzyme Activity, Fractionation, Hydrolysis, Phytic acid

Judul: In Silico Phylogenetic, Physicochemical Properties, and Structure Analysis of Phytase from Pseudomonas spp.
Abstrak: Pseudomonas sp. diketahui dapat menghasilkan tiga jenis enzim fitase berbeda yang jarang ditemukan pada bakteri lain. Fitase Pseudomonas sp. memiliki kelebihan dalam meningkatkan aktivitas katalitiknya serta mempertahankan aktivitasnya pada suhu rendah. Namun, fitase Pseudomonas belum banyak diteliti dan belum banyak dimanfaatkan dalam industri. Penelitian ini bertujuan menganalisis enzim fitase berdasarkan kekerabatan filogenetik, sifat fisikokimia, dan struktur setiap jenis enzim fitase pada berbagai spesies Pseudomonas serta mencari fitase Pseudomonas yang berpotensi untuk dikembangkan lebih lanjut. Penelitian ini menggunakan 20 fitase dari 17 spesies Pseudomonas yang didapat dari Uniport dan NCBI dengan metode berupa Neighbor Joining (NJ), Protparam, dan AlphaFold. Hasil penelitian menunjukkan bahwa ke-20 fitase ini terbagi menjadi 3 kelompok, yaitu kelompok Beta Propeller Phytase (BPP), Histidine Acid Phytase (HAP), dan 1 fitase yang belum dapat ditentukan jenisnya. Fitase-fitase tersebut juga menghasilkan struktur, sisi aktif, dan sifat fisikokimia yang berbeda-beda. Perbedaan jenis fitase didukung oleh pohon filogenetiknya, yaitu fitase HAP terletak pada cabang yang berbeda dengan fitase BPP serta jarak kekerabatan yang jauh. Kata kunci: Enzim, filogenetik, fisikokimia, fitase, Pseudomona, Pseudomonas sp. is known to produce three different types of phytase that are rarely found in other bacteria. Pseudomonas sp. phytase has the advantage of increasing its catalytic activity and maintaining its activity at low temperatures, but has not been widely studied and used in industry. This research aims to analyze phytase based on phylogenetic, physicochemical properties and structure of each type of phytase in various species of Pseudomonas and to search for Pseudomonas phytases that have the potential for further development. This research used 20 phytases from 17 Pseudomonas species obtained from Uniport and NCBI using methods such as Neighbor Joining (NJ), Protparam, and AlphaFold. The results showed that 20 phytases were divided into 3 groups. Beta Propeller Phytase (BPP), Histidine Acid Phytase (HAP), and 1 phytase that could not be determined. Phytases produce different structures, active sites and physicochemical properties. Phylogenetic tree also shows the differences of phytase. HAP phytase is located on a different branch from the BPP phytase and has a far distance of genetic relationship Keywords: Enzyme, phylogenetic, physicochemical, phytase, Pseudomonas
Keyword: Enzyme, Phylogenetic, Physicochemical, Phytase, Pseudomonas

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