• Journal of Microbiology and Biotechnology
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• v.27 no.1
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• pp.112-121
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• 2017

Edwardsiella tarda is a gram-negative pathogenic bacterium in aquaculture that can cause hemorrhagic septicemia in fish. Many secreted proteins have already been identified as virulent factors of E. tarda. Moreover, since virulent phenotypes are based on the expression regulation of virulent genes, understanding the expression profile of virulent genes is important. A quantitative RT-PCR is one of the preferred methods for determining different gene expressions. However, this requires the selection of a stable reference gene in E. tarda, which has not yet been systematically studied. Accordingly, this study evaluated nine candidate reference genes (recA, uup, rpoB, rho, topA, gyrA, groEL, rpoD, and 16S rRNA) using the Excel-based programs BestKeeper, GeNorm, and NormFinder under different culture conditions. The results showed that 16S rRNA was more stable than the other genes at different culture growth phases. However, at the same culture time, topA was identified as the reference gene under the conditions of different strains, different culture media, and infection, whereas gyrA was identified under the condition of different temperatures. Thus, in experiments, the expression of gapA and fbaA in E. tarda was analyzed by RT-qPCR using 16S rRNA, recA, and uup as the reference genes. The results showed that 16S rRNA was the most suitable reference gene in this analysis, and that using unsuitable reference genes resulted in inaccurate results.

• Korean Journal of Microbiology
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• v.32 no.4
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• pp.252-257
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• 1994

A new hydrogen sulfide-oxidation bacterium, Thiobacillus sp. was isolated from waste coal mine water around Hawsun in Chunnam province. The isolate was motile gram-negative rod shape, formed spore and grew up to be aerobically facultative chemolithotroph by using energy released from the oxidation of reduced inorganic sulfur compounds. It could assimilate various kinds of organic compounds and grew well upon thiosulfate-supplemented basal medium. To the lelvel of 32 mM in thiosulfate concentration, thiosulfate in itself was utilized as energy source for growth. However, from those of the higher concentration than 32 mM, thiosulfate functioned specifically as the substrate inhibitor rather than as the energy source. It was found that the optimum thiosulfate concentration for growth was 32 mM. The G+C content of the DNA was 65.0 mol%. The isolate had 16 : 1 + 17$_{cyc}$, 16 : 0 as their major non-hydroxylated cellular fatty acids, 3-OH 12 : 0 as a hydroxylated fatty acid and also contained unidentified $C_{18}$ branched fatty acid. The ubiquinone system in the respiratory chain was Q-9. Based on the physiological and biochemical characteristics, the isolate was assigned to a novel species of the genus Thiobacillus sp. iw.

• Journal of dental hygiene science
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• v.23 no.4
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• pp.296-301
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• 2023

Background: Periodontal disease is a major cause of tooth loss in adults and is a representative oral disease commonly suffered by most people around the world. Mainly the proliferation of Gram-negative bacteria and secreted virulence factors cause an inflammatory response and destroy periodontal tissue. Gossypetin, isolated from Hibiscus sabdariffa L, is known to have various pharmacological effects, including antibacterial and anticancer activities. We aimed to confirm the anti-inflammatory effect of gossypetin through interleukin-6 (IL-6) regulation in human gingival fibroblasts (HGFs) stimulated with lipopolysaccharide (LPS) of Porphyromonas gingivalis, a major cause of adult periodontitis. Methods: CCK-8 assay was performed to confirm the concentration-dependent cytotoxicity of gossypetin against HGFs. The secretion level and mRNA expression of IL-6, an inflammation-related cytokine, and the effect of gossypetin on these in HGFs stimulated with P. gingivalis LPS were confirmed by ELISA and qRT-PCR analysis, respectively. Results: Up to a concentration of 100 µM gossypetin with or without P. gingivalis LPS, the survival rate for HGFs was maintained at over 95% and showed no toxicity. ELISA and qRT-PCR analysis results showed that P. gingivalis LPS increased IL-6 secretion and mRNA levels in HGFs compared to the control group. However, this increase in IL-6 was significantly down-regulated by gossypetin treatment in a dose-dependent manner. In particular, 80 µM gossypetin inhibited IL-6 production to the level of the control group. Conclusion: These results indicated that gossypetin attenuated IL-6 production in HGFs stimulated by P. gingivalis LPS, which may ultimately suppress the inflammatory response in periodontal tissue. Therefore, gossypetin may have potential as a natural ingredient for the prevention and treatment of periodontal disease.

• Biotechnology and Bioprocess Engineering:BBE
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• v.10 no.5
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• pp.432-443
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• 2005

Microarray technology has contributed Significantly to the understanding of bacterial genetics and transcriptional regulation. One neglected aspect of this technology has been optimization of microarray-generated signals and quality of generated information. Full genome microarrays were developed for Clostridium acetobutylicum through spotting of PCR products that were designed with minimal homology with all other genes within the genome. Using statistical analyses it is demonstrated that Signal quality is significantly improved by increasing the hybridization volume. possibly increasing the effective number of transcripts available to bind to a given spot, while changes in labeled probe amounts were found to be less sensitive to improving signal quality. In addition to Q-RT-PCR, array validation was tested by examining the transcriptional program of a mutant (M5) strain lacking the pSOL1 178-gene megaplasmid relative to the wildtype (WT) strain. Under optimal conditions, it is demonstrated that the fraction of false positive genes is 1% when considering differentially expressed genes and 7% when considering all genes with signal above background. To enhance genomic-scale understanding of organismal physiology, using data from these microarrays we estimated that $40{\sim}55%$ of the C. acetobutylicum genome is expressed at any time during batch culture, similar to estimates made for Bacillus subtilis.

• BMB Reports
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• v.34 no.2
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• pp.166-171
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• 2001

The levels of $\gamma$-aminobutyric acid (GAGA) have been analyzed from pharbitis seeds by an AccQ-Tag amino acid analysis procedure. The GABA level of the pharbitis seeds was 125 nmole per gram fresh weight. To investigate the effects of pharbitis seed diets on serum and hepatic lipid levels, as well as enzyme activities of rats administered with ethanol chronically, Sprague-Dawley male rats were fed with either a AIN-76 diet (control), a control diet plus ethanol, a control plus pharbitis seed diet, or a control plus pharbitis seed diet plus ethanol for 30 days. Pharbitis seed diets decreased the serum total cholesterol, triglyceride, LDL-cholesterol, and $\gamma$-GTP levels that were increased by the chronic ethanol administration. In addition, pharbitis seed diets decreased the liver triglyceride and total lipid levels that were increased by the ethanol administration. However, ethanol metabolism was not retarded by the pharbitis seed supplemented diets. The present Endings, plus previous data showing the differences in the effects of cabbage diets having a high or a low level of GABA on the lipid levels and the enzyme activities of rats (Cha and Oh [2000] J. Korean Soc. Food Sci. Nutr. 29, 500-505), raise the possibility that GABA in plants could have a nutraceutical role in the recovery of chronic alcohol-related diseases.

• Journal of Microbiology and Biotechnology
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• v.18 no.9
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• pp.1496-1499
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• 2008

A Gram-negative, aerobic, rod-shaped, nonspore-forming bacterial strain, designated Gsoil $357^T$ was isolated from soil sample of a ginseng field in Pocheon Province (South Korea). The isolate contained Q-8 as the predominant ubiquinone and iso-$C_{16:0}$, iso-$C_{17:1}$ ${\omega}9c$, and iso-$C_{15:0}$ as the major fatty acids. The G+C content of the genomic DNA was 69.3 mol%. A phylogenetic analysis based on 16S rRNA gene sequences revealed that strain Gsoil $357^T$ was most closely related to Lysobacter gummosus (97.6%) and Lysobacter antibioticus (97.6%). However, the DNA-DNA relatedness value between strain Gsoil $357^T$ and its phylogenetically closest neighbors was less than 17%. On the basis of its phenotypic properties and phylogenetic distinctiveness, strain Gsoil 357T should be classified as representing a novel species in the genus Lysobacter, for which the name Lysobacter ginsengisoli sp. novo is proposed. The type strain is Gsoil $357^T$ (=KCTC $12602^T$=DSM $18420^T$).

• Parasites, Hosts and Diseases
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• v.32 no.4
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• pp.271-274
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• 1994

Stools of the residents in a village in Saengbiryang-myon, Sanchong-gun, Kyongsangnam-do were examined for the eggs of intestinal helminths. In 1987, infEction rate of 76 residents by Clonorchis sinenis was 80.3% with mean eggs per gram of feces (EPG) 27.781 C. sinensis-infected persons were treated once with praziquantel 60 mg/kg, q. i.d. Seventeen persons (22.4%) infected by Metosonimw yokogcwoi was coinfected with C. sinensis. In 1993. C. sirensis egg positive rate was 48.4% with mean EPG 5,929. Reinfection rate of follow-up cases by C. sinensis was 55.2% during 5 years and 5 months. Infection rate by MW. yokogauwai was 3.2%. This village was an endemic focus of clonorchiasis occurring reinfection high.

• Journal of Microbiology and Biotechnology
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• v.12 no.4
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• pp.643-648
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• 2002

For wastewater treatment and utilization of the biomass, a photosynthetic bacterium was isolated based on its cell growth rate, cell mass, and assimilating ability of organic acids. The isolate was a Gram-negative rod-shaped bacterium that contained a single polar flagellum and formed a lamellar intracytoplasmic membrane (ICM) system, including bacteriochlorophyll $\alpha$. The major isoprenoid quinone component was identified as ubiquinone Q-10, and the fatty acid composition was characterized as to contain relatively large amount of C-16:0 (18.74%) and C-18:1 (59.23%). Based on its morphology, phototrophic properties, quinone component, and fatty acid composition, the isolate appeared to be closely related to the Rhodopseudomonas subgroup of purple nonsulfur bacteria. A phylogenetic analysis of the isolate using its 16S rRNA gene sequence data also supported the phenotypic findings, and classified the isolate closely related to Rhodopseudomonas palustris. Accordingly, the nomenclature of the isolate was proposed as Rhodopseudomonas palustris KUGB306. A bench-scale photosynthetic bacteria (PSB) reactor using the isolate was designed and operated for the treatment of soybean curd wastewater.

• Journal of Environmental Science International
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• v.30 no.5
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• pp.369-378
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• 2021

In this study, we investigated the effects of indole on biofilm formation inhibition in Pantoea agglomerans (P. agglomerans). In the biofilm growth assay, indole inhibited biofilm formation across all the growth time. Depending on biofilm growth stage, indole exhibited biofilm inhibition and anti-bacterial effects on planktonic cells. Through the analysis of the proportion rate between biofilm and Colony Forming Units (CFU) and inhibition rate of indole, we confirmed that depending on the biofilm stage of P. agglomerans, indole treatment timing was more important than the treatment duration. By comparing gene expression rates through rt-qPCR P.agglomerans affected by indole was found to significantly change quorum sensing (pagI/R) and indole transportation (bssS) gene expressions. Throughout all, indole exhibited both antimicrobial and anti-biofilm effects on P. agglomerans. In addition, we confirmed the anti-biofilm effects of indole on mature biofilm. In conclusion, indole as a signal molecule, can exhibit anti-biofilm effects through bacterial quorum sensing inhibition and indole affects. Therefore, indole can regulate biofilm bacteria especially gram-negative opportunistic pathogens.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.11
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• pp.44-52
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• 2020

This study was conducted to investigate the effect on Brain Quotient from inhalation of blended oils. The subjects of the study were 64 people aged 20 to 59 years, with 32 in the experimental group and 32 in the control group. Blended oil with six aromas (Lavender, Bergamot, Mandarin, Lemon, Cedarwood, Roman Chamomile) was given to the experimental group, and Jojoba oil was given to the control group, for 30 minutes. Before and after the experiment, BQ tests (SRQ, BRQ, ATQ, ACQ, EQ, ASQ, CQ, and BQ) from the experimental group and the control group were compared and analyzed using a brain-training machine (NeuroHarmony S). There was a significant difference between the experimental group and the control group in three out of the eight tests analyzed ATQ (p<.05), ACQ (p<.05), BQ (p<.05). In other words, aromatherapy improves concentration and memory by increasing attention, and helps to maintain mental activity, thinking ability, and behavioral balance. BQ also represents a comprehensive brain function, and aromatherapy is a good way to maintain human mental and physical health.