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: Thermal Characteristics and Dynamics of Tropical Cyclone over Western North Pacific Ocean: A Case Study of Typhoon Songda (Chedeng) 2011
Abstrak: The frequent occasion of Tropical Cyclone (TC) over Western North Pacific (WNP) Ocean lies from 10˚N to 26˚N and 121˚E to 170˚E. Sources of TC development come from warm ocean temperature where latent heat is released during condensation processes and subsequently concentrated in the boundary layer. Relative humidity at 850-700 hPa is responsible to produce the most intense storm. Meanwhile, weak vertical wind shear between 850-200 hPa is one of the dynamical factors that lead to the development of TC. Pressure level of 850-200 hPa is chosen to minimize the thermodynamic effect in the lower troposphere. Typhoon Songda (Chedeng in the Philippines) or TSC lasted from May 18th to 30th, 2011 and strengthened into powerful Super Typhoon stage between May 24th and 27th. Long curving track and the exhibition of all sequences of TC life cycle, TSC is then considered as an ideal case of TC. The objective of the study with case of TSC is to investigate the role of thermal characteristics and dynamics on TC intensity. The research is carried out by using Advanced Research of Weather Research and Forecasting model (WRF ARW model) version 3.3. Two domains are employed in the model. The first domain situate from 02˚N to 40˚N and 118˚E to 149˚E and cover spatial resolution () of 33.1 km. The second domain situate from 09˚N to 27˚N and 119˚E to 132˚E with of 11 km. Timestep of the model () is 120 seconds. The model is supported by the following physical parameterization, i.e., Yonsei University Scheme (YSU) in the boundary layer, Kain-Fritsch scheme (KF) in the cumulus, and WRF Single-Moment 3-class scheme in the microphysics. Initial meteorological condition prior to the formation of the cyclone is generated using WRF ARW standard-release model. Sensitivity of the model output is obtained from a selected single-parameter change scenarios, namely, 10 % to 20 % decrease and increase of wind shear initial data at 850-200 hPa, and by 10 % to 20 % decrease of relative humidity initial data at 850-700 hPa. The result showed that the negative correlations between wind shear and intensity are found in wind shear scenarios. Wind shears of 10 ms-1 which lead to strengthening of the wind intensity in the early period of Typhoon development are found in wind shear scenarios. The effect of wind shear changes on wind intensity is statistically significant in the 20 % wind shear scenarios. During mature stage, weak wind intensity occurred when wind shear increase as given in the WRF standard-release and the 20 % decreasing scenario. Different situation is found in the 20 % increasing scenario where wind shear tend to weak and lead to strong wind intensity at this stage. Meanwhile, the reduction of moisture supply at 850-700 hPa resulting from 20 % decreasing relative humidity play a major role in the weakening of wind intensity and reduces mechanical energy of the cycle process as much as 300 J kg-1.
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