Judul: Karakterisasi ekstrak kasar lakase dari isolat jamur liginolitik basidiomesetes Bsd
Abstrak: Lignin merupakan penyusun biomasa tumbuhan yang sulit untuk didegradasi. Salah satu cara untuk mengatasi hal tersebut adalah menggunakan enzim lakase yang dihasilkan oleh jamur Basidimisetes. Penelitian ini bertujuan untuk mengetahui aktivitas dan kondisi optimum reaksi enzim lakase dari isolat jamur Basidiomisetes Bsd menggunakan metode spektrofotomettri.
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Judul: Isolasi, Purifikasi, dan Karakterisasi Enzim Lakase (Lac) dari Jamur Cerrena sp. B.Md.TA.1.
Abstrak: ASEP HIDAYAT. Lakase (EC 1.10.3.2) adalah enzim oksidoreduktase yang menggunakan molekul oksigen untuk mengoksidasi berbagai macam senyawa aromatik. Saat ini lakase banyak dimanfaatkan dalam proses oksidatif, delignifikasi, bioremediasi, dan menjadi subyek penelitian yang menarik sebagai komponen biofuel cell. Penelitian ini bertujuan untuk mengisolasi, memurnikan dan mengkarakterisasi lakase dari Cerrena sp. B.Md.T.A.1 yang diproduksi menggunakan media ampas sagu aren sebagai substratnya. Waktu optimasi produksi fungi terdapat pada hari ke-5.Ekstrak kasar yang diperoleh selanjutnya dimurnikan menggunakan ammonium sulfat dengan kejenuhan 0-20%, 20-40%, 40-60%, 60-80%. Fraksi 40- 60% memiliki aktivitas spesifik tertinggi yaitu sebesar 1742.28 U/mg, kemurnian 2.77 kali, nilai perolehan (yield) 13.497%. Lakase hasil pemurnian fraksi 40-60% kemudian dilakukan desalting menggunakan AKTA Start dan memiliki aktivitas spesifik sebesar 3069.74 U/mg, kemurnian 4.88 kali, nilai perolehan (yield) 1.29%. Lakase hasil desalting mencapai kondisi optimum pada pH 5.0 dan suhu 40°C. Penambahan ion logam Cu2+ dan Mn2+ dengan konsentrasi 1 mM dalam reaksi berperan sebagai aktivator, sedangkan Fe2+ dan NaN3 dengan konsentrasi 1 mM dalam reaksi berperan sebagai inhibitor. Nilai Km dan Vmaks hasil desalting adalah 0.069 mM dan 35.07 U/mL.
Keyword: ampas sagu, Cerrena sp, B.Md.T.A.1, pemurmian lakase

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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