Judul: Identifikasi Amilase dari Isolat Bakteri Lokal MII₁₀ dan DKW₈ dengan Metode Kromatografi Lapis Tipis (KLT)
Abstrak: Amilase adalah enzim yang dapat menghidrolisis pati, glikogen, dan turunan polisakarida. Amilase mikroorganisme digunakan pada industri pembuatan pati menjadi simp glukosa. Enzim ini diproduksi pada media berpati. Selama inkubasi dilakukan pengamatan nilai rapatan optis, aktivitas enzim, kadar gula reduksi, kadar protein, aktivitas spesifik enzirn, dan pH. Amilase pada media fermentasi diendapkan dengan penambahan aseton dingin, kemudian dipisahkan dengan cara sentrifugasi. Penentuan jenis amilase dilakukan dengan eara menganalisis jenis gula hasil hidrolisis enzimatis pati tapioka dengan metodeKLT.
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Judul: Karakterisasi amilase dari isolat bakteri lokal MII 10
Abstrak: Pati yang banyak dihasilkan oleh tumbuhan tingkat tinggi, terdiri dari dua komponen yaitu amilosa dan amilopektin. Amilosa merupakan polimer linier dari sekitar 1000 unit D-glukosa dengan ikatan a-1,4 glikosidik dan beberapa percabangan ikatan a-1,6 sedangkan amilopektin memiliki lebih banyak percabangan. Enzim yang mampu menghidrolisis ikatan a-1,4 glikosidik pada pati disebut enzim amilolitik atau amilase (a- amilase, ß-amilase, dan glukoamilase). Amilase tersebut sangat dibutuhkan untuk industri makanan, minuman, dan tekstil. Kebutuhan impor enzim untuk industri di Indonesia pada tahun 1995 mencapai 4.693.400 dolar Amerika (BPS, 1996). Dalam penelitian ini dilakukan karakterisasi amilase kasar yang dihasilkan bakteri isolat lokal MII10 hasil isolasi Balai Penelitian Bioteknologi Tanaman Pangan, Bogor. Karakter-karakter yang dimaksud meliputi kondisi katalitik optimum (pH dan suhu), kestabilan enzim, kinetika enzimatik, bobot molekul, serta sifat dan perilaku inhibisi dan aktivasinya terhadap beberapa senyawa kimia. Bakteri MII10 yang ditumbuhkan pada suhu 38°C menggunakan substrat pati sagu mampu menghasilkan amilase kasar (Amilase MII10) dengan aktivitas sebesar 53860,65 Unit/ml. Satu unit aktivitas amilase didefinisikan sebagai sejumlah enzim yang dapat menghasilkan 1 mmol gula reduksi (standar maltose) per menit. Dari pengujian aktivitas pada pH reaksi 4,0; 5,0, 6,0; 7,0; 8,0 dan 9,0 diketahui bahwa pH optimum Amilase MII, dicapai pada pH 7,0. Sedangkan penentuan suhu reaksi optimum, dilakukan dengan mengukur aktivitas enzim pada suhu reaksi 30°C, 40°C, 50°C, 60°C, dan 70°C. Dari pengujian tersebut diketahui suhu aktivitas optimum Amilase MII10 adalah 50° 60°C. ...
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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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