• Journal of Life Science
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• v.29 no.2
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• pp.248-255
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• 2019

This research confirmed the diversity and characterization of gut microorganisms isolated from the intestinal organs of Muraenesox cinereus, collected on the Samcheonpo Coast and Seocheon Coast in South Korea. To isolate strains, Marine agar medium was basically used and cultivated at $37^{\circ}C$ and pH7 for several days aerobically. After single colony isolation, totally 49 pure single-colonies were isolated and phylogenetic analysis was carried out based on the result of 16S rRNA gene DNA sequencing, indicating that isolated strains were divided into 3 phyla, 13 families, 15 genera, 34 species and 49 strains. Proteobacteria phylum, the main phyletic group, comprised 83.7% with 8 families, 8 genera and 26 species of Aeromonadaceae, Pseudoalteromonadaceae, Shewanellaceae, Enterobacteriaceae, Morganellaceae, Moraxellaceae, Pseudomonadaceae, and Vibrionaceae. To confirm whether isolated strain can produce industrially useful enzyme or not, amylase, lipase, and protease enzyme assays were performed individually, showing that 39 strains possessed at least one enzyme activity. Especially the Aeromonas sp. strains showed all enzyme activity tested. This result indicated that isolated strains have shown the possibility of the industrial application. Therefore, this study has contributed for securing domestic genetic resources and the expansion of scientific knowledge of the gut microbial community in Muraenesox cinereus of South Korea.

• Journal of Microbiology and Biotechnology
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• v.23 no.4
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• pp.518-526
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• 2013

Gut-derived lipopolysaccharides (LPS) are critical to the development and progression of chronic low-grade inflammation and metabolic diseases. In this study, the effects of probiotics Lactobacillus and Bifidobacterium on gut-derived lipopolysaccharide and inflammatory cytokine concentrations were evaluated using a human colonic microbiota model. Lactobacillus reuteri, L. rhamnosus, L. plantarum, Bifidobacterium animalis, B. bifidum, B. longum, and B. longum subsp. infantis were identified from the literature for their anti-inflammatory potential. Each bacterial culture was administered daily to a human colonic microbiota model during 14 days. Colonic lipopolysaccharides, and Gram-positive and negative bacteria were quantified. RAW 264.7 macrophage cells were stimulated with supernatant from the human colonic microbiota model. Concentrations of TNF-${\alpha}$, IL-$1{\beta}$, and IL-4 cytokines were measured. Lipopolysaccharide concentrations were significantly reduced with the administration of B. bifidum ($-46.45{\pm}5.65%$), L. rhamnosus ($-30.40{\pm}5.08%$), B. longum ($-42.50{\pm}1.28%$), and B. longum subsp. infantis ($-68.85{\pm}5.32%$) (p < 0.05). Cell counts of Gram-negative and positive bacteria were distinctly affected by the probiotic administered. There was a probiotic strain-specific effect on immunomodulatory responses of RAW 264.7 macrophage cells. B. longum subsp. infantis demonstrated higher capacities to reduce TNF-${\alpha}$ concentrations ($-69.41{\pm}2.78%$; p < 0.05) and to increase IL-4 concentrations ($+16.50{\pm}0.59%$; p < 0.05). Colonic lipopolysaccharides were significantly correlated with TNF-${\alpha}$ and IL-$1{\beta}$ concentrations (p < 0.05). These findings suggest that specific probiotic bacteria, such as B. longum subsp. infantis, might decrease colonic lipopolysaccharide concentrations, which might reduce the proinflammatory tone. This study has noteworthy applications in the field of biotherapeutics for the prevention and/or treatment of inflammatory and metabolic diseases.

• Korean Journal of Microbiology
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• v.49 no.4
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• pp.415-418
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• 2013

Since the development of the next generation sequencing (NGS) technology, 16S rRNA gene sequencing has become a major tool for microbial community analysis. Recently, human microbiome project (HMP) has been completed to identify microbes associated with human health and diseases. HMP achieved characterization of several diseases caused by bacteria, especially the ones in human gut. While human intestinal bacteria have been well characterized, little have been studied about other animal intestinal bacteria. In this study, we surveyed diversity of livestock animal fecal microbiota and discuss importance of studying fecal microbiota. Here, we report the initiation of the fecal microbiome project in South Korea.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.3 no.1
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• pp.7-18
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• 1970

The present paper deals with mortality and pathogenetic investigation of the oysters Crassostrea gigas cultured by tile coventional bamboo and hanging method in Kimhae and Koje-Do in 1969. The results of the investigation may be summarized as follows: 1. Mortality of the oysters by the bamboo method in Kimhae was $9.5\%$ in June, $10.2\%$ In July, $12.3\%$ in August and $12.1\%$ in September, respectively, 2. Mortality of the oysters cultured by the hanging method in Koje-Do was $2.4\%$ in June, $2.9\%$ in July, $30.7\%$ in October, $37.3\%$ in November and $30.0\%$ in December, respectively 3. The diseased oysters had severe inflammation, necrosis and multiple abscess in the epithelia of stomach, mid-gut, digestive tubules, blood vessels and gonads, mucous membrane and surrounding tissue. 4. From August gram negative bacteria were found in the nodules of connective tissue and multiple abscess of the diseased oysters. Particularly the connective tissue of the diseased oysters contained more bacteria than epithelia. 5. Since the bacteria are less abundant in the region of digenerated tissue, mortality of the oysters is not caused only by the infectious bacteria but seems that is also caused by other environmental factors such as extreme temperatures and salinities.

• The Journal of the Korean dental association
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• v.40 no.8 s.399
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• pp.620-627
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• 2002

Oral health depends on the intergrity of the oral mucosa for prevention of the penetration of microbes and macromolecules that might be infectious, allergenic or antigenic. The intraoral immune systems include the tonsils, adenoids and nasopharyngeal-associated lymphoreticular tissue, or NALT. Mucosal inductive sites of the gastrointestinal tract(Peyer's patches and the appendix) and solitary lymph nodes collectively compose the gut-associated lymphoreticualr tissue, or GALT system. Both NALT and GALT are inductive regions where foreign antigens derived from viruses, bacteria, yeast and other molecules are encountered. The integration of tissues in NALT and GALT as part of the mucosal immune system, is very important to keep the oral immune system.

• Journal of Korean Society of Environmental Engineers
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• v.30 no.6
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• pp.653-658
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• 2008

The bacteria responsible for the reduction of ammonia concentration in a food-wastewater treatment facility were isolated and their characteristics were analyzed. The isolated bacteria were closely related to the bacteria belonging to genus Citrobacter, Enterobacter, Buttiauxella, Shigella, and Aeromonas, which were found in gut of animals, indicating the isolated bacteria may come from the butchery-byproduct of pigs which is the main component of wastewater. When we monitored the concentration of nitrite and nitrate in the process, it was relatively constant, indicating the isolated bacteria reduce ammonia concentration through ammonia assimilation. Based on the removal efficiency of ammonia by the isolated bacteria, we concluded that they play a role in the reduction of odorous compounds.

• Asian-Australasian Journal of Animal Sciences
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• v.24 no.8
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• pp.1128-1135
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• 2011

This study was conducted to investigate the effect of dietary green tea extract (GTE) on the performance, carcass and gastrointestinal tract (gut) traits, caecal coliform bacteria count, and pH and color (CIE $L^*$, $a^*$, and $b^*$) values of the breast muscle in broilers. A total number of 600 day-old broilers (Ross 308) was allocated to three treatments with four replicates containing 50 (25 males and 25 females) birds. The dietary treatments consisted of the basal diet as the control (0GTE) and diets with GTE at 0.1 (0.1GTE) or 0.2 (0.2GTE) g/kg. Body weights and the feed intake of broilers were measured at 1, 21 and 42 days, the feed intake was measured for different periods and the feed conversion ratio was calculated accordingly. At 42 day four birds per replicate were slaughtered for the determination of carcass and organ weights, caecal coliform bacteria count, and also quality of the breast muscle. The dietary GTE increased the body weight, feed efficiency, carcass weight and dressing percentage and decreased caecal coliform bacteria count of broilers (p<0.05). The 0GTE broilers consumed (p<0.01) less feed than the 0.1GTE birds in the entire experimental period. The relative abdominal fat weight and gut length of broilers in the 0.2GTE were tended to be lower (p<0.07) than those in the 0GTE group. The breast meat from 0.1GTE birds had a lower pH value when compared to that from 0GTE birds. The 0.1GTE broilers had lighter breast meat than 0GTE and 0.2GTE birds. The dietary GTE increased $a^*$ and $b^*$ values of the breast meat. Thus this product appeared to have a measurable impact on CIE color values of the breast meat in broilers. The results of the present study may indicate that the improved production results in the group with added GTE are directly connected with physiological mechanisms such as the regulation of the caecal micro-flora.

• Journal of Microbiology and Biotechnology
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• v.26 no.6
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• pp.1035-1045
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• 2016

To evaluate the effects of lactic acid bacteria (LAB) on Peyer's patch cells, mice were treated with a high dose of kanamycin to disturb the gut microbial environment. The overarching goal was to explore the potential of LAB for use as a dietary probiotic that buffers the negative consequences of antibiotic treatment. In vitro, LAB stimulated the production of immunoglobulin A (IgA) from isolated Peyer's patch cells. Inflammation-related genes (TNF-α, IL-1β, and IL-8) were up-regulated in Caco-2 cells stimulated with lipopolysaccharide (LPS), while tight-junction-related genes (ZO-1 and occludin) were down-regulated; the effects of LPS on inflammatory gene and tight-junction gene expression were reversed by treatment with LAB. Mice treated with a high dose of kanamycin showed increased serum IgE levels and decreases in serum IgA and fecal IgA levels; the number of Peyer's patch cells decreased with kanamycin treatment. However, subsequent LAB treatment was effective in reducing the serum IgE level and recovering the serum IgA and fecal IgA levels, as well as the number of Peyer's patch cells. In addition, ZO-1 and occludin mRNA levels were up-regulated in the ileum tissues of mice receiving LAB treatment. Lactic acid bacteria can enhance the intestinal immune system by improving the integrity of the intestinal barrier and increasing the production of IgA in Peyer's patches. Lactic acid bacteria should be considered a potential probiotic candidate for improving intestinal immunity, particularly in mitigating the negative consequences of antibiotic use.

• Journal of Microbiology
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• v.43 no.4
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• pp.345-353
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• 2005

The complex ecosystem of intestinal micro flora is estimated to harbor approximately 400 different microbial species, mostly bacteria. However, studies on bacterial colonization have mostly been based on culturing methods, which only detect a small fraction of the whole microbiotic ecosystem of the gut. To clarify the initial acquisition and subsequent colonization of bacteria in an infant within the few days after birth, phylogenetic analysis was performed using 16S rDNA sequences from the DNA iso-lated from feces on the 1st, 3rd, and 6th day. 16S rDNA libraries were constructed with the amplicons of PCR conditions at 30 cycles and $50^{\circ}C$ annealing temperature. Nine independent libraries were produced by the application of three sets of primers (set A, set B, and set C) combined with three fecal samples for day 1, day 3, and day 6 of life. Approximately 220 clones ($76.7\%$) of all 325 isolated clones were characterized as known species, while other 105 clones ($32.3\%$) were characterized as unknown species. The library clone with set A universal primers amplifying 350 bp displayed increased diversity by days. Thus, set A primers were better suited for this type of molecular ecological analysis. On the first day of the life of the infant, Enterobacter, Lactococcus lactis, Leuconostoc citreum, and Streptococcus mitis were present. The largest taxonomic group was L. lactis. On the third day of the life of the infant, Enterobacter, Enterococcus faecalis, Escherichia coli, S. mitis, and Streptococcus salivarius were present. On the sixth day of the life of the infant, Citrobacter, Clostridium difficile, Enterobacter sp., Enterobacter cloacae, and E. coli were present. The largest taxonomic group was E. coli. These results showed that microbiotic diversity changes very rapidly in the few days after birth, and the acquisition of unculturable bacteria expanded rapidly after the third day.

• Ocean Science Journal
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• v.41 no.2
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• pp.113-119
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• 2006

Seventeen lactic acid bacterial strains (LAB) were isolated using MRS agar medium from Jeotgal, a Korean fermented food, purchased at the Jukdo market of Pohang. To identify the strains isolated, they were tested by examining their cell morphologies, gram-staining, catalase activity, arginine hydrolase activity, D-L lactate form and carbohydrate fermentation. According to the phenotypic characteristics, three strains were tentatively identified as Lactobacillus spp., ten were Enterococcus spp. (or Streptococcus spp., or Pediococcus spp.) and the rest were Leuconostoc spp. (or Weissella spp.). Five strains among 17 were chosen by preliminary bacteriocin activity test. Four bacterial strains which inhibited both indicator microorganisms were identified by 16S rRNA sequencing. The results are as follows; Leuconostoc mesenteroides (HK 4), Leuconostoc mesenteroides (HK 5), Leuconostoc mesenteroides(HK 11), Streptococcus salivarius(HK 8). In order to check LAB which are showing a high survival rate in gut, we investigated three strains inhibiting both indicator microorganisms in artificial gastric acid and bile juice -all except HK8. The three strains mentioned above grew in extreme low acid conditions.