Judul: Studi sifat penempelan bakteri asam laktat asal air susu ibu
Abstrak: Probiotics are live microorganism that will exert beneficial effect to the host when ingested in sufficient amounts. The ability to adhere to intestinal epithelial cells is a prerequisite for probiotic action. The aim of this study was to identify the adherence properties of nine lactic acid bacteria isolated from breast milk which are potential as probiotic (L. rhamnosus A15, Lactobacillus A27, L. rhamnosus A29, L. rhamnosus R14, L. rhamnosus R21, L. rhamnosus R23, L. rhamnosus R26, L. rhamnosus B10, L. rhamnosus B13, dan L. rhamnosus B16). This study was conducted in three stages i.e. (1) the evaluation of adherence method on mucus of broiler and rat intestine (2) the evaluation of adherence properties that consist of hydrophobicity, autoaggregation, adhesion to rat intestinal cells, and adhesion to the surface of rat intestine and (3) the competition of adhesion between LAB and EPEC which included competition, exclusion, displacement, and observation of the bacteria adherence on the surface of rat intestine used SEM. The use of rat intestine gave better result in showing the adhesion ability of LAB tested than mucus of broiler. The exposure of rat intestine in suspension of LAB raised the total number of LAB which indicated the attachment of LAB isolates while reducing the total number of E. coli which indicated competition between LAB and indigenous E. coli on the surface of rat intestine. All of nine LAB isolates tested have low autoaggregation ability due to their hydrophobicity. There were only three LAB isolates that adhered to rat intestinal cells, they were A27, B16, and R23. However, all LAB isolates adhered to the surface of rat intestine. The most adhesive LAB was A27 followed by B16, R14, and R23. The degree of adherence of LAB was strain specific and affected by the type of adherence medium. The competition test showed that the LAB isolates tested were able to compete with EPEC. The adhesion of the LAB isolates affected by the number of LAB, the higher the number of LAB the higher the number of adhering bacteria. The exclusion and displacement test showed that the LAB isolates tested were likely able to attach well on the surface of rat intestine. R23 isolate was not able to be excluded by EPEC while B16 isolate was slightly excluded. Both LAB isolates were not able to displace EPEC. The observation of adherence using SEM showed bacilliform of bacteria on the surface of rat intestine that have been incubated with LAB R14, R23, B16, and A27.
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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: Closed Knight’s Tour pada Papan Catur Berbentuk Persegi Panjang dengan Ukuran Maksimal 8 × 8
Abstrak: Closed Knight’s Tour merupakan langkah kuda yang mengunjungi setiap kotak pada papan catur tepat satu kali dengan langkah kuda berawal dan berakhir pada kotak yang sama. Graf yang terbentuk dari closed knight’s tour dinotasikan sebagai graf G(m,n), dengan m adalah banyaknya baris dan n adalah banyaknya kolom. Graf tersebut memuat Hamiltonian cycle. Sebuah graf terhubung G adalah graf bipartite jika dan hanya jika graf tersebut tidak memiliki cycle dengan panjang ganjil. Papan catur yang memenuhi syarat cukup untuk memiliki closed knight’s tour adalah papan catur berukuran 5 × 6, 5 × 8, 6 × 6, 6 × 7, 6 × 8, 7 × 8, dan 8 × 8.
Keyword: bipartite, closed knight’s tour, hamiltonian cycle, knight’s tour, teori graf