Judul: Identification of Bacterial Isolates IR5 and IR9,  Relationships, Optimization of Media, and Synthesized Pigments
Abstrak: Bakteri isolat IR9 dan IR5 merupakan bakteri fotosintetik ungu yang biasa ditemukan di laut dan diketahui dapat menghasilkan pigmen. Isolat IR5 dan IR9 telah berhasil diisolasi dari laut. Penelitian ini bertujuan menganalisis kekerabatan antar kedua isolat tersebut berdasarkan sekuens 16S rRNA, mengoptimasi media pertumbuhan, dan mengidentifikasi jenis pigmen yang dihasilkan oleh kedua isolat tersebut. Analisis kekerabatan kedua isolat berdasarkan kemiripan sekuens 16S rRNA menunjukkan isolat IR5 dan IR9 tergolong ke dalam spesies Rhodovulum sulfidophilum. Kedua isolat tersebut diduga merupakan strain yang berbeda. Berdasarkan pengamatan secara kualitatif pada tingkat kepekatan warna kultur, isolat IR9 memiliki pertumbuhan yang lebih baik apabila dibandingkan dengan isolat IR5 pada media pertumbuhan yang sama. Komposisi media pertumbuhan yang paling optimum dan direkomendasikan untuk pertumbuhan isolat IR5 dan IR9 adalah 1% gula pasir + 0,5% NPK + 2,5% NaCl kasar. Media yang mengandung NPK mendukung pertumbuhan bakteri yang lebih optimum dibandingkan dengan media yang mengandung TSP tanpa NPK. Isolat bakteri IR9 mengalami pertumbuhan optimum pada hari ke-3. Identifikasi berdasarkan serapan panjang gelombang pada spektrofotometer UV-VIS menunjukkan bakteri tersebut mampu menghasilkan beberapa jenis pigmen, yaitu bacteriopheophytin, β-carotene, canthaxanthin, dan bacteriochlorophyll a.
Keyword: Identifikasi pigmen, kurva tumbuh, optimasi media, pohon filogenetik Rhodovulum sulfidophilum, Identifikasi pigmen, kurva tumbuh, optimasi media, pohon filogenetik Rhodovulum sulfidophilum

Judul: Analisis keragaman genetik dan sintasan sejumlah isolat bekteri fotosintetik anoksigenik asal laut
Abstrak: Eighty isolates of anoxygenic photosynthetic bacte- ria were isolated from 49 samples collected from a number of Indonesian seashores. All of the isolates showed similar color (i.e. photosynthetically in red to brownish red) when grown Sea Water Complete (SWC) medium. under illumination of tungsten light (± 200 lux). Many of the isolates were gram-negative, rod shape bacteria. However, genetic analysis employing Asel-schizotyping of 45 selected isolates indicated extensive genetic diversi- ty which apparently did not show any biogeographic relat- edness. A number their survival of selected isolates in sterile sea water were examined for supplemented with peptone (0,1 g/1) and yeast extract (0,02 g/1). All of the isolates demonstrated significant growth until 5 days of incubation and most of them maintained their viability up to 7 days of incubation. However, SKX121 is the only isolate which could maintain its viability up to 2 x 109 cell/ml after 7 days of incubation. From 47 isolates examined, 35 isolates were signifi- cantly more tolerant to Na2S (up to 100 µg/ml than isolate MW4, a reference isolate which has been known as sulphide tolerant anoxygenic photosynthetic bacteria.
Keyword: keragaman genetik, Bakteri fotosintetik, laut

Judul: Hedging strategy for loan with interest rate Cap.
Abstrak: A bank usually charges a specific nominal interest for a loan, which is influenced by the market’s interest rate. When the market interest rates fluctuate, the customer will face financial loss with the growing burden. Interest rate cap is one of the solutions to anticipate any negative impacts of increasing interest rate, by limiting the maximum interest rate paid by customer to the bank. Thus, customer gets a guarantee against increase in interest rate. To obtain this guarantee, the customer is required to pay a premium. The aims of this paper are to analyze the form of a loan with the interest rate cap strategy, and to discuss Vasicek model approach to determine the amount of the premium. A numerical illustration is given to show the advantage of the interest rate cap strategy. The results show that the interest rate cap will provide protection to the customer as the market interest rates fluctuate. Vasicek model states that the price cap interest rate can be expressed as an expected value of a random variable that has bivariate normal distribution. Numerical results show that this strategy provides benefits in the form of lower amortization cost than that of a loan without interest rate cap.
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