Judul: In vitro Adhesiveness of Beef Isolated Lactic Acid Bacteria on Intestinal Surface
Abstrak: The gut micro flora is various in number and composition, and its condition strongly effect the health of the host. Probiotic is live microorganism that to believed having potential to control pathogenic bacteria in digestive system. Lactic acid bacteria (LAB) is the one of the most popular bacteria to be used as probiotic. This experimental aims were to investigate the adhesive ability of LAB to the intestinal epithelium, to identify bacterial gram expression and to evaluate the influence of mucus component to the adhesion ability. The finding may provide more various LAB species which highly potential as a probiotic starter. The data were analyzed by ANOVA using the GLM procedure of MINITAB. There were 5 LAB strains and control evaluated in vitro using rat ileum as a model. The ileum sample (1x1 cm2) were prepared for 2 treatment: group one will be incubated in bacterial suspension after phosphate buffer saline ( PBS ) flushing and the other group are directly incubated without flushing at 37oC for 30 minute. Bacterial adhesion will be evaluated with micro-technique using gram staining. All of LAB showed a normal growth after 24 hours incubated at 37 °C in MRS with agar. The different strains of LAB had no significant on bacterial population of 1A5, 2B2, 2B4, 2C12 and 1A32 isolates. Treatment directly incubated without flushing at 37oC for 30 minute no significantly increase the growth final population of LAB (P>0,05), especially isolate 1A5, 2C12 and 1A32. Result hematoxylin-eosin expression to indicate LAB population was significant adhesive ability given the highly on treatment directly incubated without flushing than treatment will be incubated in bacterial suspension after PBS flushing. As a conclusion bacteria adhesive ability the influence by cell surface protein mucous on aggregation and adhesiveness membrane cell of LAB to intestinal epithelial.
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Judul: Characterization of indigenous lactic acid bacteria from beef as probiotic and identification by 16s rRNA gene sequencing
Abstrak: Functional foods are foods that have health promising benefit over and above their basic nutritional value. Probiotics are included as component of functional foods. Probiotics are live microorganisms which when administered in adequate amounts confer a health benefit on the host. The research was aimed to characterize the probiotic properties and to identify indigenous lactic acid bacteria (LAB) isolated from fresh beef derived from traditional market around Bogor, West Java, Indonesia. The twenty eight LAB isolates showed different ability to survive under simulated gastrointestinal conditions. Only 10 isolates could survive well at pH 2.0 (survival rate over than 50%) and the population increased at pH 2.5, 3.2 and 7.2. The ten LAB isolates (strain 2B4, 1B1, 1A5, 2C2, 2D1, 2B2, 1C4, 2B1, 1A32 and 2C12) could survive well at 0.5% bile salt, showed antibacterial activities and good coagregation capabilities against the tested pathogenic bacteria (Escherichia coli ATCC 25922, Salmonella Typhimurium ATCC 14028, Enteropathogenic Escherichia coli/EPEC, and Staphylococcus aureus ATCC 25923) and could adhere to intestinal surface by in vitro analysis. The 16S rRNA gene could be amplified by PCR (Polymerase Chain Reaction) to get single band with designed primer. Identification by 16S rRNA gene sequencing of 20 isolates showed that 11 isolates were identified as Lactobacillus plantarum, 6 isolates as Lactobacillus acidophilus, 2 isolates as Pediococcus pentosaceous and 1 isolate as Enterococcus faecium. The ten LAB isolates were proven to be probiotic candidates, which consist of 7 isolates of Lactobacillus plantarum (strain 1B1, 1A5, 2D1, 2B2, 1C4, 2B1, 2C12) and 3 isolates of Lactobacillus acidophilus (strain 2B4, 2C2, 1A32). Lactobacillus plantarum 2C12 and Lactobacillus acidophilus 2B4 were further evaluated to prevent diarrheae caused by EPEC. Albino rats (Rattus norvegicus) were daily orally administered by 108 cfu/ml of both probiotics without or simultaneously infected with EPEC (106 cfu/ml). Negative control was not infected by probiotic and EPEC while positive control was challenged with EPEC alone. It was observed that rats administered by L. plantarum 2C12 and L. acidophilus 2B4 which were challenged with EPEC had better performances when compared with the positive control for daily weight gain, feed consumption and feed efficiency rate. Both probiotics could prevent diarrhea caused by EPEC by increasing total population of lactic acid bacteria 1 log cfu/cm2 on mucosa of cecum and 1 log cfu/g on content of cecum, reducing population of E.coli 1-2 log cfu/cm2 on mucosa of cecum and 1 log cfu/g on cecum content also increasing 33.66-71.79 x 106 cell on lymphocytes. L. acidophilus 2B4 had better probiotic characteristics than L. plantarum 2C12, with specific health function to prevent diarrhea caused by EPEC.
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Judul: Penentuan Harga Opsi Put Amerika dengan Simulasi Monte Carlo
Abstrak: An American option is an option that can be exercised at the strike price anytime before or on the date of expiration. In this thesis, Monte Carlo simulation for valuation of American option is presented. Monte Carlo simulation is one of the numerical methods used to determine the price of American options. The simulation provides several examples of initial stock price , rate of interest , exercise time , volatility , and strike price K. The simulation study shows the cost of the option c decreases when S increases, c decreases when r increases, c increases when T increases, c increases when  increases, and c increases when K increases.
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