Judul: Isolation and Confirmation of Local Bacillus cereus from Fresh Milk
Abstrak: Susu segar merupakan bahan pangan yang sering dikonsumsi untuk memenuhi kebutuhan gizi, pertumbuhan, dan perkembangan khususnya pada anak. Tingginya kandungan gizi membuat susu menjadi media yang optimal untuk pertumbuhan bakteri sehingga kerap mengakibatkan keracunan pangan. Bacillus cereus adalah salah satu bakteri patogen yang ditemukan dalam susu yang dapat mengakibatkan keracunan pangan serta merupakan penyebab penyakit bawaan pangan kedua tertinggi di Indonesia namun belum bisa dipastikan sumbernya. Penelitian mengenai keberadaannya dalam susu segar perlu dilakukan. Penelitian ini bertujuan mengetahui keberadaan dan karakteristik B. cereus dalam susu segar lalu mengonfirmasi isolat menggunakan perangkat cepat API 50CHB. Penelitian terdiri dari dua bagian yaitu evaluasi prevalensi dan konfirmasi B. cereus dalam susu segar. Sampel susu segar yang berasal dari tiga peternakan di Kota Bogor diisolasi kemudian koloni yang menunjukkan karakteristik B.cereus dilakukan uji katalase, pewarnaan Gram dan pewarnaan spora. Hasil isolasi menyatakan bahwa prevalensi susu segar yang terduga mengandung isolat B. cereus adalah 85% (17/20). Hasil konfirmasi menggunakan perangkat cepat API 50CHB menunjukkan 4 dari 5 isolat yang terpilih terkonfirmasi sebagai B. cereus (88% - 99,9%), sementara 1 isolat tidak terkonfirmasi sebagai B. cereus. Hal ini menyatakan bahwa uji katalase, pewarnaan Gram dan pewarnaan spora dapat digunakan sebagai langkah awal konfirmasi B. cereus.
Keyword: Bacillus cereus, isolasi, Prevalensi, Konfirmasi, Susu Segar

Judul: Isolation and Characterization of Bacillus cereus from Fresh Vegetables
Abstrak: Sayuran merupakan komoditas yang memiliki kandungan gizi dan kadar air tinggi sehingga rentan ditumbuhi oleh mikroorganisme, salah satunya Bacillus cereus. B. cereus dapat menyebabkan pembusukan dan penyakit bawaan pangan dan merupakan patogen penyebab penyakit bawaan pangan kedua terbesar di Indonesia. Oleh karena itu, penelitian mengenai keberadaannya dalam berbagai produk perlu dilakukan. Penelitian ini bertujuan mengetahui keberadaan, konsentrasi, dan karakteristik B. cereus dalam sayuran segar, serta mengonfirmasi isolat yang diperoleh menggunakan API 50 CHB. Penelitian dibagi menjadi isolasi, karakterisasi, serta konfirmasi isolat B. cereus yang diperoleh. Sebanyak 20 sampel sayuran diambil dan diisolasi menggunakan mannitol-egg yolk-polymyxin (MYP) agar. Koloni terduga selanjutnya dikarakterisasi dengan pewarnaan Gram, spora, uji katalase, dan dikonfirmasi dengan perangkat API 50 CHB. Isolasi menghasilkan 45 isolat terduga B. cereus dari 20 sampel, dengan konsentrasi 1,55 – 3,61 log CFU/g. Urutan sampel dari yang mengandung B. cereus paling banyak adalah kangkung, kentang, wortel dan bawang, lalu buncis. Karakterisasi dengan pewarnaan dan katalase menunjukkan 35 dari 45 isolat memiliki karakteristik morfologi serupa dengan B. cereus. Dari 20 sampel sayuran, 19 sampel mengandung isolat dengan katakteristik morfologi B. cereus sehingga prevalensinya adalah 95%. Sebanyak 4 isolat dengan karakteristik B. cereus dikonfirmasi dengan API 50 CHB dan terkonfirmasi sebagai B. cereus dengan persentase 99,70 – 99,90%, sementara itu 3 isolat yang tidak memiliki karakteristik B. cereus juga terkonfirmasi sebagai spesies selain B. cereus. Hal ini menunjukkan pewarnaan Gram, spora, dan uji katalase dapat digunakan sebagai pra-konfirmasi B. cereus dari pangan., Vegetables are commodities containing high nutrient and moisture content, so they are prone to microbial growth, such as Bacillus cereus. B. cereus in foods can cause spoilage and foodborne illnesses and was the second most pathogens to cause foodborne illnesses in Indonesia, hence research on its occurrence in various products needs to be done. This study aimed to determine the occurrence, concentration, and characteristics of B. cereus in fresh vegetables, and to confirm the isolates using API 50 CHB. The research consisted of isolation, characterization, and confirmation using a rapid test kit. Twenty samples of vegetables was collected and presumptive B. cereus was isolated using mannitol-egg yolk-polymyxin (MYP) agar. The suspected colonies were characterized by Gram, spores staining, catalase test, and confirmed using API 50 CHB.We obtained 45 suspected B. cereus isolates from all 20 samples, with concentration of 1,55 – 3,61 log CFU/g. The order of samples containing the most B. cereus was water spinach, potatoes, carrots and onions, then snap beans. Characterization concluded that 35 out of 45 suspects were having morphology resembling B. cereus. Of the 20 vegetables, 19 were confirmed to contain isolates with B. cereus morphology hence the prevalence of 95%. A total of 4 isolates with B. cereus morphology were confirmed as B. cereus 99,70 – 99,90% using API 50 CHB and 3 isolates without B. cereus morphology were confirmed as non B. cereus. The result indicates that Gram, spore staining and catalase test can be use for pre confirmation of B. cereus in foods.
Keyword: Bacillus cereus, biochemical confirmation, characterization, isolasi, isolation, karakterisasi, konfirmasi biokimiawi, sayuran, vegetables

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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