Judul: Ekstrak Kasar Biopigmen Bakteri Laut yang Memiliki Aktivitas Antibakteri dan Antioksidan serta Identifikasi Senyawa Kimianya
Abstrak: Metabolit sekunder yang dihasilkan oleh bakteri laut asosiasi spons sangat beragam, salah satunya adalah biopigmen. Biopigmen bakteri memiliki berbagai potensi dalam bidang farmakologis seperti antibakteri, antifungi, dan antioksidan. Penelitian ini bertujuan menganalisis aktivitas antibakteri dan antioksidan ekstrak biopigmen dari isolat SAB E-64 dan P1.S9, mengidentifikasi kandungan kimianya, serta mengidentifikasi jenis isolat bakteri tersebut melalui pendekatan molekuler. Uji aktivitas antibakteri menunjukkan ekstrak biopigmen SAB E-64 paling baik menghambat pertumbuhan Staphylococcus aureus sedangkan biopigmen isolat P1.S9 paling baik menghambat pertumbuhan Bacillus subtilis. Hasil uji toksisitas berupa nilai LC50, 144,62 µg/ml untuk SAB E-64 dan 122,15 µg/ml untuk P1.S9 menggunakan metode Brine Shrimp Lethality Test (BSLT). Uji aktivitas antioksidan biopigmen menunjukkan nilai IC50 sebesar 238,25 µg/ml untuk biopigmen SAB E-64 serta 164,05 µg/ml untuk biopigmen P1.S9. Analisis senyawa kimia dengan GC-MS menunjukkan bahwa komponen yang mendominasi ekstrak biopigmen SAB E-64 adalah golongan alkana sedangkan P1.S9 didominasi oleh asam lemak. Analisis gen 16S-rRNA menunjukkan bahwa SAB E-64 memiliki kesamaan terdekat dengan Kocuria marina dan P1.S9 dengan Pseudomonas aeruginosa.
Keyword: bakteri laut, biopigmen, antibakteri, antioksidan, senyawa kimia.

Judul: Antimicrobial, Antioxidant, and Toxicity Activity of Marine Actinomycetes Biopigment Extract
Abstrak: Aktinomiset merupakan bakteri Gram-positif yang mempunyai potensi sebagai sumber metabolit sekunder baru. Salah satu metabolit sekunder tersebut adalah biopigmen. Biopigmen yang dihasilkan oleh aktinomiset mempunyai berbagai aktivitas biologis. Penelitian ini bertujuan menguji kemampuan antimikrob, antioksidan, dan toksisitas ekstrak biopigmen aktinomiset laut kode HV11.P3 dan SCA54.P2. Aktivitas antimikrob diuji terhadap beberapa mikrob patogen dan menunjukkan hasil terbaik dalam menghambat pertumbuhan Bacillus subtilis ATCC 19659 untuk ekstrak HV11.P3 kemudian Escherichia coli ATCC 8739 untuk SCA54.P2.Aktivitas antioksidan terhadap radikal DPPH menunjukkan nilai IC50 231,084 μg/ml untuk HV11.P3 dan 369,296 μg/ml untuk SCA54.P2. Hasil uji toksisitas berupa nilai LC50 yaitu 94,603 μg/ml untuk HV11.P3 dan 131,220 μg/ml untuk SCA54.P2 menggunakan metode Brine Shrimp Lethality Test (BSLT). Senyawa kimia penyusun ekstrak diidentifikasi menggunakan GC-MS. Hasilnya senyawa 1H-Purine-2,6-dione, 3,7-dihydro-1,3,7-trimethyl- (CAS) menjadi penyusun dominan ekstrak HV11.P3 dengan peak area 44,65% dan 5-Methoxypyrrolidin-2-one dengan luas peak area 30,23% untuk ekstrak biopigmen SCA54.P2. Analisis gen 16S rRNA menunjukkan bahwa HV11.P3 memiliki kesamaan terdekat dengan Micromonospora chalcea strain 1464-217L dan SCA54.P2 dengan Micromonospora tulbaghiae strain TVU1., Actinomycetes are Gram-positive bacteria that have potency as a source of new secondary metabolites. One of those secondary metabolites is biopigments. Biopigments produced by actinomycetes have various biological activities. This study aimed to determine antimicrobial, antioxidant, and toxicity activity from marine actinomycetes biopigment extract coded as HV11.P3 and SCA54.P2. Antimicrobial activities were tested against several pathogenic bacteria and showed the best result for inhibiting Bacillus subtilis ATCC 19659 for HV11.P3 and Escherichia coliATCC 8739 for SCA54.P2. The antioxidant activity against DPPH radical showed IC50 value 231,084 μg/ ml for HV11.P3 and 369,296 μg/ ml for SCA54.P2. The toxicity test results (LC50) based on Brine Shrimp Lethality Test (BSLT) were 94,603 μg/ ml and 131,220 μg/ ml for HV11.P3 and SCA54.P2, respectively. The major chemical compounds of HV11.P3 extract were identified as 1H-Purine-2,6-dione, 3,7-dihydro-1,3,7-trimethyl- (CAS) (peak area 44,65%) and 5-Methoxypyrrolidin-2-one for SCA54.P2 (peak area 30,23%). The 16S rRNA gene analysis showed that HV11.P3 had the closest similarity with Micromonospora chalcea strain 1464-217L and SCA54.P2 with Micromonospora tulbaghiae strain TVU1.
Keyword: BSLT, DPPH, Extract, GC-MS, 16S rRNA gene

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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