Judul: Isolasi Bakteri Epibiotik Penghasil Senyawa Antibakteri dari Permukaan Karang
Abstrak: Marine bacteria that live on the surface of other organisms (epibiotic bacteria) such as marine algae and invertebrates have shown a high percentage to produce bioactive metabolites and sugges as a potential new source of novel antibacterial products.
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Judul: Penapisan Bakteri Penghasil Senyawa Antimikrob Asal Spons Laut
Abstrak: Sponges are invertebrate found on coral reef ecosystems. Sponges produce many bioactive compounds as a result of secondary metabolites. The bioactive compounds is produced by microorganisms in the presence of sponges tissue as symbionts. Bioactive compounds are potential to be used in the biomedical and pharmaceutical fields, one of them is antimicrobial. This study aims to screen bacteria from marine sponges of Bira Island, Thousand Islands, DKI Jakarta Province, namely Callyspongia sp. and Petrosia sp. that could potentially produce antimicrobial compounds. The results of isolation using six types of medium showed a total of 147 bacterial isolates were isolated from the sponge type Callyspongia sp. and Petrosia sp. The suitable mediums used to isolate bacteria associated with sponge to obtain various types of bacterial colonies, were medium Nutrient Agar and Zobel Marine Agar. The results of the screening obtained from 26 isolates (13%) could produce antimicrobial compound. Seven isolates (5%) of them were able to inhibit five bacterial targets, i.e. Pseudomonas aeruginosa, Staphylococcus aureus, Bacillus subtilis, Escherichia coli (ATCC 8739), and Enterophatogenic Escherichia coli (EPEC). The isolates were CAL36, CAL42, PTR8, PTR21, PTR40, PTR41 and PTR47. Gram staining performed on 26 bacterial isolates showed all of them belong to the group of gram-negative bacteria. Six isolates among 26 isolates were positive hemolysis derived from the sponge type Callyspongia sp., namely CAL22, CAL24, CAL25, CAL26, CAL34, and CAL49.
Keyword: Bogor Agricultural University (IPB), sponge Petrosia sp., sponge Callyspongia sp, hemolysis, Bira Island, antimicrobial compound

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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