Judul: Production and Characterization of Bacteriocin from Lactobacillus fermentum 2B2 and Its Antimicrobial Activities Against Pathogen Bacteria
Abstrak: Bakteri asam laktat (BAL) yang terdapat secara alami di dalam daging atau susu memiliki kemampuan sebagai bahan pengawet alami karena menghasilkan senyawa antimikroba. Salah satu senyawa antimikroba yang dihasilkan yaitu bakteriosin. Penggunaan bakteriosin sebagai biopreservative sangat menjanjikan karena bersifat bakterisidal atau bakteristatik terhadap bakteri lain khususnya bakteri yang berkerabat dekat dengan bakteri penghasilnya (Vuyst and Vandamme, 1994). Potensi bakteriosin ini meningkatkan penelitian dalam mempelajari dan mendapatkan informasi yang lebih dalam mengenai produksi bakteriosin, purifikasi parsial bakteriosin, konsentrasi penghambatan minimum dalam minimum inhibitor concentration (MIC) dan minimum bactericidal concentration (MBC) terhadap bakteri patogen, serta karakterisasi bakteriosin melalui uji kepekaan bakteriosin terhadap enzim katalase dan proteolitik, Produksi dan Karakterisasi Bakteriosin Asal Lactobacillus fermentum 2B2 dan Aktivitas Antimikrobanya terhadap Bakteri Patogen.
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Judul: Produksi dan Karakterisasi  Bakteriosin Asal Lactobacillus  plantarum  1A5 serta Aktivitas Antimikrobanya  terhadap Bakteri Patogen
Abstrak: The aims of this research were to study antimicrobial activity of bacteriocin produced by lactic acid bacteria Lactobacillus plantarum 1A5 in six different media (media with NaCl 1%, combination of NaCl 1% and YE 3%, and trypton 1% inducers that were conditioned on pH 5 dan pH 6, respectively). Characteristic of bacteriocin 1A5 determined by catalase and proteolytic enzymes with antagonistic assay against pathogenic bacterias (Staphylococcus aureus ATCC 25923, Salmonella typhimurium ATCC 14028 and enteropathogenic Escherichia coli K11) and determination of Minimum Inhibitory Concentration (MIC) and Minimum Bactericide Concentration (MBC)’s value against Staphylococcus aureus ATCC 25923. The result showed that the inhibitory activity was produced significantly by crude bacteriocin 1A5 from media with trypton 1% inducer and was conditioned at pH 6. Characterization of active compound from crude bacteriocin 1A5 could be classified as bacteriocin neither antimicrobial compounds such as hydrogen peroxide because it was stable to catalase treatment. The other characteristic of its bacteriocin was nature proteinaeous that showed loss it’s activity after trypsin treatment against Staphylococcus aureus ATCC 25923 and enteropathogenic Escherichia coli K11, neither Salmonella typhimurium ATCC 14028. Inhibition activity of crude bacteriocin 1A5 could explained with MIC and MBC’s value, especially against Staphylococcus aureus ATCC 25923. MIC’s and MBC’s value needed respectively 70% dan 80% concentration of crude bacteriocin.
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Judul: Tree berdiameter lima adalah graceful
Abstrak: This manuscript presents some proofs that every tree of diameter five is graceful. A graceful tree is a graph which has a graceful labelling. This labelling assigns absolute difference of connected vertices, such that the resulting edge labels are mutually distinct. There are three theorems to be considered. First theorem proves that every tree of diameter four is graceful. Second theorem proves that every tree of diameter five is graceful or nearly graceful. The third theorem improves the second theorem and shows that every tree of diameter five is nearly graceful, which can be transformed into graceful using some certain patterns.
Keyword: Graf, Pelabelan graceful, Bogor Agricultural University, Institut Pertanian Bogor, IPB