• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.28 no.6
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• pp.15-20
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• 2014

Recently, LED (Light Emitting Diode) application research is studying by using a specific wavelength. LED plant factory produced a lot of green plants in a closed spaces, so it should be taken to guard against harmful microbes. Until today, a lot of studies for green plant production in plant factory is proceed but there were no study on harmful microbes in plant factory. Thus, the analysis on sterilization for harmful microbes in plant factory were experimented using UV (Ultra Violet) LED with 282nm of wavelength. As a results on sterilization of three harmful microbes, 50% of sterilization efficiency was achieved after 2.5 hours, 97% was achieved after 12 hours of UV LED irradiation, respectively.

• Korean Journal of Microbiology
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• v.44 no.4
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• pp.358-361
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• 2008

Effect of extract of fermented dropwort (Oenanthe stolonifera) on growth of intestinal harmful/useful bacteria and enzyme activity were investigated in vitro. The extract showed strong inhibition on harmful microbes including Vibrio and Salmonella, but mild inhibition on Bifidobacterium longum in both agar plate and liquid cultivation. Minimum inhibitory concentration (MIC) value of B. longum was the highest among tested microbes. Inhibition effect of fermented extract on harmful microbes increased according to fermentation period. Extract of fermented dropwort showed inhibitory effects on activity of microbial ${\beta}$-glucuronidase and tryptophanase. The inhibitory effects were also proportional to fermentation period. As consequence, it is assumed that the uptake of fermented dropwort might be useful for human intestinal health.

• Journal of Korean Society of Water and Wastewater
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• v.23 no.4
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• pp.491-497
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• 2009

The purpose of this study is to propose a method of controlling redtide microbes which grow abundantly and form harmful algal bloom in eutrophic waterbody with yellow loess and hydrogen peroxide. In the laboratory test, hydrogen peroxide was applied to single species of C. polykrikoides and multispecies of redtide microbes. The seawater was evaluated by the pre-test analysis including chlorophyll-a, luminance and transmittance. The test results showed that both single and mixed species of redtide microbes could be controlled with the dose of 30mg $H_2O_2/L$. Residual hydrogen peroxide was completely decomposed with the addition of powdered yellow loess at 2g/L~10g/L. However, the decomposition rate of residual hydrogen peroxide for sintered granular yellow loess was relatively low compared to the use of powdered one. With the addition of dissolved oxygen concentration was increased at a rate of 0.013 mg DO/mg $H_2O_2$, which is a little lower than the one predicted theoretically. No evidence for any detrimental effects on Artemia, a type of brine shrimps, was shown up to the concentration of 100mg $H_2O_2/L$.

• Applied Chemistry for Engineering
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• v.22 no.2
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• pp.119-124
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• 2011

Currently, people are exposed to many harmful diseases. Therefore, there are many schemes, such as automation of productive facilities, development of information and communication technology, enhanced the quality of human life and wealth. However, these processes lead to weakened immune system. Thus, people are more vulnerable to infections from pathogens and environmental stress. Misuse and abuse of drugs resulted in the rapid emergence of multidrug-resistant microbes and tumors, therefore, to find new antibiotics are urgently needed. One of them is a peptide-antibiotic, that is not or less occurred a drug-resistance, comparing to conventional drugs. Peptides with various antibiotic activities have been identified from life organisms. The present review provides an overview of activities and application of peptide antibiotics.

• IMMUNE NETWORK
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• v.15 no.1
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• pp.1-8
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• 2015

Innate immune cells survey antigenic materials beneath our body surfaces and provide a front-line response to internal and external danger signals. Dendritic cells (DCs), a subset of innate immune cells, are critical sentinels that perform multiple roles in immune responses, from acting as principal modulators to priming an adaptive immune response through antigen-specific signaling. In the gut, DCs meet exogenous, non-harmful food antigens as well as vast commensal microbes under steady-state conditions. In other instances, they must combat pathogenic microbes to prevent infections. In this review, we focus on the function of intestinal DCs in maintaining intestinal immune homeostasis. Specifically, we describe how intestinal DCs affect IgA production from B cells and influence the generation of unique subsets of T cell.

• Journal of Microbiology and Biotechnology
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• v.16 no.10
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• pp.1513-1517
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• 2006

One single lactic acid producing bacterium, isolated from kimchi, inhibited the growth and adherence of Helicobacter pylori to the human gastric epithelial cell line MKN-45. This isolate was identified as Lactobacillus plantarum and termed L. plantarum strain PL9011. The adherence of H pylori, in the presence of live or nonviable L. plantarum strain PL9011 (10-fold CFU), decreased to 14-20%. The spent culture supernatant of L. plantarum strain PL9011 resulted in the eradication of H pylori. This activity remained stable following neutralization and heat treatment, but not following pepsin treatment, thereby suggesting small peptides as the inhibitory factor. L. plantarum strain PL9011 did not produce any harmful metabolites or enzymes. The results obtained in this study suggest that the L. plantarum strain PL9011 may be a potential novel probiotic for the stomach.

• The Korean Journal of Food And Nutrition
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• v.26 no.3
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• pp.470-475
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• 2013

The objective of this study was to investigate the perceptions and purchase behaviors on foreign matters in food. For that, we conducted a survey of 348 adults living in a metropolitan area. Concern over the presence of foreign matters in food was a lower than that for other harmful factors such as heavy metals, BSE, harmful microbes and so on. 70% of respondents would not take the snack which was detected a rat's head, including the manufacturer's product and similar products with it after the foreign matter incident. In contrast, about of 54% respondents were willing to buy canned tuna after the incident. It is necessary to prepare more detail management and policy on foreign matters in food.

• The Plant Pathology Journal
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• v.24 no.3
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• pp.283-288
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• 2008

Plant leaf surface is an important niche for diverse epiphytic microbes, including bacteria and fungi. Plant leaf surface plays a critical frontline defense against pathogen infections. The objective of our study was to evaluate the effectiveness of a starch-based super-absorbent polymer(SAP) combination, which enhances water potential and nutrient availability to plant leaves. We evaluated the effect of SAP on the maintenance of bacterial populations. In order to monitor bacterial populations in situ, a SAP mixture containing Pseudomonas syringae pv. tabaci that expressed recombinant green fluorescent protein(GFPuv) was spray-challenged onto whole leaves of Nicotiana benthamiana. The SAP combination treatment enhanced bacterial robustness, as indicated by disease severity and incidence. Unexpectedly, bacterial numbers were not significantly different between leaves treated with the SAP combination and those treated with water alone. Furthermore, young leaves treated with the SAP combination had more severe symptoms and a greater number of bacterial spots caused by primary and secondary infections compared to young leaves treated with the water control. In contrast, bacterial cell numbers did not statistically differ between the two groups, which indicated that measurement of viable GFP-based bacterial spots may provide a more sensitive methodology for assessing virulence of bacterial pathogens than methods that require dilution plating following maceration of bacterial-inoculated leaf tissue. Our study suggests that the SAP combination successfully increased bacterial aggressiveness, which could either be used to promote the ability of biological agents to control weedy plants or increase the robustness of saprophytic epiphytes against competition from potentially harmful microbes.

• Journal of Microbiology and Biotechnology
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• v.34 no.4
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• pp.828-837
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• 2024

Vancomycin (VAN) and metronidazole (MTR) remain the current drugs of choice for the treatment of non-severe Clostridioides difficile infection (CDI); however, while their co-administration has appeared in clinical treatment, the efficacy varies greatly and the mechanism is unknown. In this study, a CDI mouse model was constructed to evaluate the therapeutic effects of VAN and MTR alone or in combination. For a perspective on the intestinal ecology, 16S rRNA amplicon sequencing and non-targeted metabolomics techniques were used to investigate changes in the fecal microbiota and metabolome of mice under the co-administration treatment. As a result, the survival rate of mice under co-administration was not dramatically different compared to that of single antibiotics, and the former caused intestinal tissue hyperplasia and edema. Co-administration also significantly enhanced the activity of amino acid metabolic pathways represented by phenylalanine, arginine, proline, and histidine, decreased the level of deoxycholic acid (DCA), and downregulated the abundance of beneficial microbes, such as Bifidobacterium and Akkermansia. VAN plays a dominant role in microbiota regulation in co-administration. In addition, co-administration reduced or increased the relative abundance of antibiotic-sensitive bacteria, including beneficial and harmful microbes, without a difference. Taken together, there are some risks associated with the co-administration of VAN and MTR, and this combination mode should be used with caution in CDI treatment.

• Journal of Microbiology and Biotechnology
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• v.25 no.9
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• pp.1510-1518
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• 2015

In this work, we wanted to develop a probiotic from famous longevity villages in Korea. We visited eight longevity villages in Korea to collect fecal samples from healthy adults who were aged above 80 years and had regular bowel movements, and isolated lactic-acid-producing bacteria from the samples. Isolated colonies that appeared on MRS agar containing bromophenol blue were identified by means of 16S rRNA sequencing, and 102 of the isolates were identified as lactic-acid-producing bacteria (18 species). Lactobacillus fermentum was the most frequently found species. Eight isolates were selected on the basis of their ability to inhibit the growth of six intestinal pathogens (Escherichia coli O157:H7, Salmonella enterica subsp. enterica Typhimurium, Salmonella enterica subsp. enterica Enteritidis, Enterococcus faecalis, Staphylococcus aureus, and Listeria monocytogenes) and their susceptibility to 15 antimicrobial agents. Among these eight isolates, four Lactobacillus fermentum isolates were found not to produce any harmful enzymes or metabolites. Among them, Lactobacillus fermentum isolate no. 24 showed the strongest binding to intestinal epithelial cells, the highest immune-enhancing activity, anti-inflammation activity, and anti-oxidation activity as well as the highest survival rates in the presence of artificial gastric juice and bile solution. This isolate, designated Lactobacillus fermentum PL9988, has all the characteristics for a good probiotic.