• Korean Journal of Microbiology
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• v.47 no.4
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• pp.308-315
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• 2011

The purpose of this work was to examine the antimicrobial activity derived from the lactic acid bacterium, UK-3 isolated from the vaginas of women of childbearing age. Various physiological and biochemical properties of this strain were characterized. Both the BIOLOG system and phylogenetic analysis using 16S rRNA sequencing were utilized for identification, and the strain was designated as Lactobacillus plantarum UK-3, and registered in GenBank as [JK266589]. Growth rate, production of organic acids (e.g., lactic acid and acetic acid), and pH during growth were monitored. The maximum concentrations of lactic acid and acetic acid were approximately 684.11 mM and 174.26 mM, respectively, and pH changed from 7.0 to 3.7 after 72 h of incubation. High performance liquid chromatography was used to confirm lactic acid and acetic acid production. Significant antimicrobial activity of the concentrated supernatant was demonstrated against various Gram-positive (e.g., Staphylococcus aureus, Staphylococcus epidermidis, Methicillin-resistant Staphylococcus aureus, Enterococcus faecalis, Neisseria species., Listeria monocytogenes), Gram-negative bacteria (e.g., Escherichia coli, Klebsiella pneumoniae, Proteus mirabilis), and yeast (e.g., Candida albicans) by the plate diffusion method. As a result, the concentrated L. plantarum UK-3 cultures had lower acidity and inhibited the growth of all microorganisms tested, whereas the growth of L. acidophilus was not affected.

• Korean Journal of Microbiology
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• v.41 no.2
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• pp.140-145
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• 2005

Streptomyces natalensis ATCC27448 produces natamycin, a commercially important macrolide antifungal antibiotic. For molecular genetic study of S. natalensis, we have developed a system for introducing DNA into S. natalensis via conjugal transfer from Escherichia coli. An effective transformation procedure for S. natalensis was established based on transconjugation from E, coli ET12567/pUZ8002 using a ${\Phi}C31$-derived integration vector, pSET152, containing oriT and attP fragments. The high frequency was obtained on MS medium containing 10 mM $MgCl_2$ using $6.25\times10^8$ of E.coli donor cells without heat treatment of spores. In addition, southern blot analysis of exconjugants and the sequence of plasmids containing DNA flanking the insertion sites from the chromosome revealed that S. natalensis contains a single ${\Phi}C31$ attB site and at least a secondary or pseudo attB site. Similar to the case of various Streptomyces species, a single ${\Phi}C31$ attB site of S. natalensis is present within an ORF encoding a pirin-homolog, but a pseudo-attB site is present within a distinct site (GenBank accession no. $YP\_117731$) and also its sequence deviates from the consensus sequences of attB sequence.

• Journal of the Korean Society for Library and Information Science
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• v.41 no.2
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• pp.219-236
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• 2007

This study was to build a collaborative digital library model between KSTI and JST for sharing science and technology information created in Korea and Japan. For this study, digital library framework, it's main concepts and widely-used digital library technologies were investigated. And also, best practices of collaborative digital library were surveyed to characterize collaborative digital library trends. Collaborative Sci-Tech digital library model proposed in this study can be applied in real environment and expanded into other institutions and/or subject areas.

• Journal of Microbiology and Biotechnology
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• v.27 no.11
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• pp.2044-2051
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• 2017

The main pathological hallmark of Alzheimer's disease is the deposition of amyloid-beta ($A{\beta}$) peptides in the brain. $A{\beta}$ has been widely used to mimic several aspects of Alzheimer's disease. However, several characteristics of amyloid-induced Alzheimer's disease pathology are not well established, especially in mice. The present study aimed to develop a new Alzheimer's disease model by investigating how $A{\beta}$ can be effectively aggregated using prokaryotes and eukaryotes. To express the $A{\beta}42$ complex in HEK293 cells, we cloned the $A{\beta}42$ region in a tandem repeat and incorporated the resulting construct into a eukaryotic expression vector. Following transfection into HEK293 cells via lipofection, cell viability assay and western blotting analysis revealed that exogenous $A{\beta}42$ can induce cell death and apoptosis. In addition, recombinant His-tagged $A{\beta}42$ was successfully expressed in Escherichia coli BL21 (DE3) and not only readily formed $A{\beta}$ complexes, but also inhibited the proliferation of SH-SY5Y cells and E. coli. For in vivo testing, recombinant His-tagged $A{\beta}42$ solution ($3{\mu}g/{\mu}l$ in $1{\times}PBS$ containing $1mM\;Ni^{2+}$) was injected stereotaxically into the left and right lateral ventricles of the brains of C57BL/6J mice (n = 8). Control mice were injected with $1{\times}PBS$ containing $1mM\;Ni^{2+}$ following the same procedure. Ten days after the sample injection, the Morris water maze test confirmed that exogenous $A{\beta}$ caused an increase in memory loss. These findings demonstrated that $Ni^{2+}$ is capable of complexing the 50-kDa amyloid and that intracerebroventricular injection of $A{\beta}42$ can lead to cognitive impairment, thereby providing improved Alzheimer's disease models.