Judul: Isolasi dan Karakterisasi Bakteri Proteolitik Asal Feses Kuda (Equus caballus)
Abstrak: Penelitian ini bertujuan untuk mengisolasi dan menyeleksi bakteri proteolitik sebagai kandidat bakteri pendegradasi protein asal feses kuda secara morfologi dan biokimia. Penelitian dilakukan dalam tiga tahap. Tahap pertama adalah isolasi bakteri asal feses kuda dengan Skim Milk Agar + Rumen 10% dan tahap kedua dilakukan skrining bakteri proteolitik untuk mengetahui nilai indeks proteolitik tertinggi. Tahap ketiga dari hasil isolat terpilih dilanjutkan serangkaian uji karakterisasi yang meliputi uji gula pereduksi, uji makroskopis, uji katalase, pewarnaan gram, dan uji aktivitas enzim protease. Analisis aktivitas enzim menggunakan Rancangan Acak Lengkap (RAL) pola faktorial dengan perlakuan suhu dan pH. Suhu yang diuji adalah 40 ℃, 50 ℃, dan 60 ℃, pH yang diuji adalah 5, 6, 7, 8 dengan 3 kali ulangan. Hasil penelitian didapatkan isolat dengan nilai indeks proteolitik tertinggi yaitu isolat 1 (985.T.K.1.4 di SMA), isolat 2 (985.T.K.1.4 di SMA+R) dan isolat 3 (SMA+R.K.4.10). Hasil uji karakterisasi menunjukkan bahwa ketiga isolat memiliki morfologi yang hampir sama. Ketiga isolat tersebut merupakan bakteri gram negatif, dapat mendegradasi gula pereduksi dan memiliki aktivitas katalase. Pengujian morfologi menunjukkan bahwa ketiga isolat termasuk genus Bacteroides. Uji aktivitas enzim protease menunjukkan bahwa ketiga isolat melakukan aktivitas optimum pada suhu 60 ℃ dan pH 5 dengan nilai aktivitas enzim isolat 1 sebesar 0,027 U mL-1, isolat 2 dan 3 sebesar 0,018 U mL-1. Kesimpulannya, isolat 2 merupakan isolat yang memiliki nilai indeks proteolitik tertinggi dan perlu dilakukan analisis lebih lanjut.
Keyword: aktivitas enzim, karakterisasi, kuda, protease

Judul: Isolasi, dan karakterisasi bakteri selulolitik asal feses kuda (Equus caballus).
Abstrak: Penelitian ini bertujuan untuk mengisolasi dan karakterisasi bakteri selulolitik asal feses kuda yang diambil dari Equistrian center, Unit Rehabilitasi dan Reproduksi, Sekolah Kedokteran Hewan dan Biomedis Institut Pertanian Bogor (URR SKHB IPB). Penelitian dilakukan dalam tiga tahap. Tahap pertama adalah isolasi bakteri asal feses kuda dengan media N 98-5 dan media selektif selulolitik, tahap kedua dilakukan penapisan bakteri selulolitik dan tahap ketiga uji karaktererisasi isolat terpilih (uji gula-gula pereduksi, uji makroskopis, uji katalase, pewarnaan gram, dan uji aktivitas enzim selulase). Analisis aktivitas enzim menggunakan rancangan acak lengkap (RAL) pola faktorial dengan suhu, pH dan substrat yang berbeda. Suhu yang digunakan ialah 40o C, 50o C dan 60oC, pH yang digunakan ialah 5,6,7,8 serta substrat yang digunakan ialah CMC, Avicel dan Kertas Saring. Hasil penelitian ini di peroleh 3 isolat dengan nilai indeks selulolitik tertinggi yaitu isolat 1 (985.P.K.2.2), isolat 2 (985.P.K.2.3) dan isolat 3 (985.P.K.2.4). Hasil uji karakteriasi menunjukkan ketiga isolat memiliki morfologi yang berbeda. Isolat 2 dan 3, gram positif dan isolat 1, gram negatif. Hasil uji gula-gula pereduksi menunjukkan isolat 1 mampu mereduksi laktosa dan sukrosa, isolat 2 mampu mereduksi laktosa, dan isolat 3 mampu mereduksi sukrosa. Isolat 2 merupakan isolat dengan nilai indeks tertinggi dibandingkan isolat 1 dan 3 serta memiliki aktivitas enzim tertinggi. Hasil uji aktivitas enzim menunjukkan isolat 2 menghasilkan aktivitas terbaik dengan suhu optimum pada suhu 40o C dan pH optimum 5 dengan substrat kertas saring. Disimpulkan bahwa isolat 2, kandidat isolat terbaik dan hasil uji karakterisasi isolat 2 mengarah pada genus dari Bacillus., This study aimed to isolate and characterize cellulolytic bacteria from horse faeces taken from the Equistrian center, Rehabilitation and Reproduction Unit, School of Veterinary Medicine and Biomedical, Bogor Agricultural University (URR SKHB IPB). The research was conducted in three stages. The first stage was the isolation of bacteria from horse feces using N 98-5 media and selective cellulolytic media, the second stage was screening for cellulolytic bacteria and the third stage was the characterization test of the selected isolates (reducing sugar test, macroscopic test, catalase test, gram staining, and cellulase activity). The enzyme activity analysis used a factorial completely randomized design (CRD) with different temperatures, pH and substrates. The temperatures used were 40oC, 50oC and 60oC, the pH used was 5,6,7,8 and the substrates used were CMC, Avicel and filter paper. The results of this study obtained 3 isolates with the highest cellulolytic index value, namely isolate 1 (985.P.K.2.2), isolate 2 (985.P.K.2.3) and isolate 3 (985.P.K.2.4). The results of the characterization test showed that the three isolates had different morphology. Isolates 2 and 3, gram positive and isolate 1, gram negative. The results of the reducing sugar test showed that isolate 1 was able to reduce lactose and sucrose, isolate 2 was able to reduce lactose, and isolate 3 was able to reduce sucrose. Isolate 2 was the isolate with the highest index value compared to isolates 1 and 3 and had the highest enzyme activity. The results of the enzyme activity test showed that isolate 2 produced the best activity at an optimum temperature of 40oC and an optimum pH of
Keyword: bacillus, cellulolytic bacteria, enzyme activity, faeces hourse, fibrobacter

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