• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.1521_1522
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• 2009

Chemotaxis is the directed movement of cells in gradients of signaling molecules, an essential biological process that underlies morhpogenesis during development, and the recruitment of immune cells to sites of infection. Especially, bacterial chemotaxis has utilized as an important prelude to study metabolism, prey-predator relationship, symbiosis, other ecological interactions in microbial communities. Recently, novel analytical formats integrated with microfluidics were introduced to investigate the chemotaxis of the cells with the precise control of chemical gradient and small volume of cells. In this study, we present a method to detect bacterial chemotaxis by direct fluidic contacting. The developed fluidic-handling method is driven by capillary force, hydrophobic barrier and a cohesion force between fluids. We have investigated the chemotactic response of E Coli. and Pseudomonas aeruginosa to three kinds of chemoeffectors such as HEPES buffer, peptone and chloroform.

• Journal of Chest Surgery
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• v.53 no.6
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• pp.400-402
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• 2020

Primary tracheobronchial lipoma is an extremely rare entity, the diagnosis of which is often missed initially. Cases are generally diagnosed late after initial treatment for asthma and bronchitis. We report a case of a 42-year-old man with a left main bronchus lipoma that caused near-total obstruction. The lipoma was treated by bronchoscopic resection with an electrosurgical snare and cryoablation.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.50 no.4
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• pp.265-267
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• 2005

Study on effectiveness of Bradyrhizobium japonicum on soybean [Glycine max (L.) Merr.], local cultivar 'Sathiya' were carried out in the garden soil of Trib-huvan University. Different parameters like nodulation, chlorophyll content in fresh leaves and growth of plant in inoculated and uninoculated plant was studied. Pot experiment was conducted in the green house to evaluate the effectiveness of B. japonicum on soybean. It was observed that B. japonicum inoculation increased the number of nodules, shoot length of plant and total chlorophyll content in fresh leaves of soybean plant. However, root length was decreased in all inoculated plants.

• Journal of Microbiology and Biotechnology
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• v.4 no.3
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• pp.176-182
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• 1994

The light-organ symbiont of pine cone fish, Vibrio fischeri, senses its presence in the host and responds to environmental changes by differentially expressing its symbiosis-related luminescence genes. The V. fischeri luminescence genes are activated by LuxR protein in the presence of an autoinducer. In an effort to elucidate the mechanism of regulation of luxR, a plasmid containing luxR was mutagenized in vitro with hydroxylamine and a luxR mutant plasmid was isolated by its ability to activate luminescence genes cloned in E. coli in the absence of the autoinducer. The specific base change identified by DNA sequencing was only single base transition at ＋78 from the transcriptional start of luxR. Based on a Western immunoblot analysis, the nucleotide change directed the synthesis of much higher level of LuxR protein without any amino acid substitutions. The results suggest that the region including the ＋78th base is presumably internal operator required for autorepression of luxR, and the increased cellular level of LuxR results in activation of luminescence genes by autoinducer independent fashion.

• Proceedings of the Korean Institute of Interior Design Conference
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• 2007.05a
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• pp.110-113
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• 2007

Modernity which is superficial phenomenon set off the mass scale for mass consumption and provide uniformly artificial environment. But natural destruction, environment pollution, resources exhaustion and so on has been caused by this and now ecology is threatened by destruction and damage beyond the limitation and human beings survival is even threatened. Accordingly furniture development for environment preservation considered environment problem is the urgent real situation. Recent paradigm is the concept of Eco-design which is the green design possible to live together in symbiosis, and new types of alternative furniture are needed in Korea as well. 'Furniture for disassembly' is presented as new method for alternative furniture.

• Microbiology and Biotechnology Letters
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• v.32 no.1
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• pp.1-10
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• 2004

Many bacteria monitor their population density and control the expression of specialized gene sets in response to bacterial cell density based on a mechanism referred to as quorum sensing. In all cases, quorum sensing involves the production and detection of extracellular signaling molecules, auto inducers, as which Gram-negative and Gram-positive bacteria use most prevalently acylated homoserine lactones and processed oligo-peptides, respectively. Through quorum-sensing communication circuits, bacteria regulate a diverse array of physiological functions, including virulence, symbiosis, competence, conjugation, antibiotic production, motility, sporulation, and biofilm formation. Many pathogens have evolved quorum-sensing mechanisms to mount population-density-dependent attacks to over-whelm the defense responses of plants, animals, and humans. Since these AHL-mediated signaling mechanisms are widespread and highly conserved in many pathogenic bacteria, the disruption of quorum-sensing system might be an attractive target for novel anti-infective therapy. To control AHL-mediated pathogenicity, several promising strategies to disrupt bacterial quorum sensing have been reported, and several chemicals and enzymes have been also investigated for years. These studies indicate that anti-quorum sensing strategies could be developed as possible alternatives of antibiotics.

• Ocean and Polar Research
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• v.22 no.1
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• pp.1-13
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• 2000

Chemoautotrophic symbiotic bacteria of organisms inhabiting the hydrothermal vent and cold seep communities in the deep-sea were histologically examined using a transmission electron microscopy on symbionts of Calyptogena sp. A from the site east off Miyako (water depth at 1,700m), Calyptogena sp. B from the Calyptogena Site, vestimentiferan tube worm Lamellibrachia sp. A from Sagami Bay Lamellibrachia sp. B from Calyptogena Site of the Iheya Ridge, pogonophoran tube worms from Sagami Bay and Calyptogena Site of the Iheya Ridge, Bathymodiolus spp. from Sagami Bay, the Iheya Ridge and the North Fiji Basin. Based on the morphological microscopic observations, two species of Calyptogena from Miyako and the Iheya Ridge, two species of vestimentiferan tube worms from Sagami Bay and the Iheya Ridge, and pogonophoran tube worms from Sagami Bay and the Iheya Ridge observed to host sulfur-oxidizing symbiotic bacteria. The occurrence of chemosynthetic symbionts in these organisms was expected beforehand based on the ecological observations of their habitats. Other members of these groups from the world oceans, and the recent advances in the symbiosis at vents and seeps were reviewed.

• Journal of Plant Biology
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• v.34 no.1
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• pp.31-35
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• 1991

Induction of symbiosis between N. muscorum and cultured tobacco cells associately cultured on nitrogen-free medium and effects of polyamines on culture condition were carried out. Analysis of amino acid composition in associate cultures showed increase in total amino acid amounts than single culture of cultured tobacco cells and methionine was markly increased in associative culture on N-free medium treated with 1 mM spermine. These results indicated that the composition of amino acids increased effectively in associative cultures by nitrogen fixation of N. muscorum.scorum.

• Journal of the Korean Wood Science and Technology
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• v.43 no.5
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• pp.628-640
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• 2015

Cellulase is the key enzyme in the use of cellulose-based biomaterials. Because of its structure, cellulose is difficult to be degraded by enzymes. In order to utilize cellulose-based biomaterials efficiently, evolutionary wisdom of how to use enzymes accurately and harmoniously in a biological system is needed, such as the cellulose digestive system in animals. In this study, the symbiotic bacteria from snails, Achatina fulica, were identified and their cellulase activity was evaluated. The 16S rRNA sequence analysis of 100 aerobic bacteria showed that they belonged to 9 genus and almost half of the bacteria were Lactococcus spp. Among 100 identified strains, only two Aeromonas sp. strains showed cellulase activity. Aeromonas sp. KMBS020 had both endo-${\beta}$-glucanase and ${\beta}$-glucosidase activities but Aeromonas sp. KMBS018 had ${\beta}$-glucosidase activity only. None of the 100 bacterial colonies had any cellobiohydrolase activity.

• Mycobiology
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• v.30 no.1
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• pp.18-21
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• 2002

Four arbuscular mycorrhizal fungal(AMF) inocula collected from three arable sites in Korea were used to determine plant growth, mycorrhizal root colonization rate and spore production in three different host plant species; Sorghum bicolor, Allium fistulosum, Tagetes patula. Growth of plant treated with AMF differed from those without AMF. Different AMF inocula showed significantly different root colonization rates and spore production of AMF on the wild plants, A. fistulosum and T. patula, but did not on the cultivated plant, S. bicolor. Results suggested that indigenous mycorrhizal fungal community would be important factors in mycorrhizal symbiosis, and play important roles in the plant succession.