• Korean Journal of Soil Science and Fertilizer
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• v.47 no.4
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• pp.254-261
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• 2014

The scientific information between microbial activities and chemical properties of reclaimed tidal soil is not enough to apply for reclamation projects. This study was conducted to investigate the relation between chemical properties and microbial activities of reclaimed tidal lands located at western coastal area (25 samples from Nampo, Ewon, Sukmoon and Shihwa sites). Most of the reclaimed soils showed chemical characteristics as salinity soil except Nampo site. The major component influenced the salinity of reclaimed soil was identified as a sodium from the relationship between EC and exchangeable cation. With an increase in EC of soil, the population of mesophilic bacteria decreases whereas halotolerant and halophilic bacteria increases. The population of mesophilic bacteria increased with an increase in both organic matter and dehydrogenase activity. However, the population of halotolerant and halophilic bacteria decreased with an increase in organic matter. Based on the relation between chemical property and microbial activity of reclaimed tidal soil, electrical conductivity and organic matter as chemical properties of soil, population of mesophilic bacteria, halotolerant and halophilic bacteria and dehydrogenase activity as microbial activities could be the major parameters for reclamation process.

• Korean Journal of Food Science and Technology
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• v.34 no.1
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• pp.136-139
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• 2002

The discrimination of the agricultural origin, especially locally produced of imported products such as black rices was investigated by using electronic nose. Volatile components from these products were discriminated by six metal oxide sensors without pretreatment. Pattern recognition was carried out. Principal component analysis showed the differences between imported and locally produced ones. The number of 57 from 69 species of black rices were recognized as locally produced one (83.33%) and 11 from 13 species one (imported black rices) was correctly discriminated. Unknown habitat of black rice could be identified by artificial neural network system whether the imported or not. Also commercial electronic nose (E-nose 5000) that was combined with metal oxide sensor and conducting polymer sensor showed 92.75% (locally produced black rices) and 92.31% (imported one) of discrimination.

• Journal of dental hygiene science
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• v.20 no.4
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• pp.213-220
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• 2020

Background: The leaves of Perilla frutescens, commonly called perilla and used for food in Korea, contain components with a variety of biological effects and potential therapeutic applications. The purpose of this study was to identify the components of 70% ethanol extracted Perilla frutescens (EEPF) and determine its inhibitory effects on oral microbial activity and production of nitric oxide (NO) and prostaglandin E2 (PGE2) in lipopolysaccharides (LPS)-stimulated Raw264.7 macrophages, consequently, to confirm the possibility of using EEPF as a functional component for improving the oral environment and preventing inflammation. Methods: One kg of P. frutescens leaves was extracted with 70% ethanol and dried at -70℃. EEPF was analyzed using high-performance liquid chromatography analysis, and antimicrobial activity against oral microorganisms was revealed using the disk diffusion test. Cell viability was elucidated using a methylthiazolydiphenyl-tetrazolium bromide assay, and the effect of EEPF on LPS-induced morphological variation was confirmed through microscopic observation. The effect of EEPF on LPS-induced production of pro-inflammatory mediators, NO and PGE2 was confirmed by the NO assay and PGE2 enzyme-linked immunosorbent assay. Results: The main component of EEPF was rosemarinic acid, and EEPF showed weak anti-bacterial and anti-fungal effects against microorganisms living in the oral cavity. EEPF did not show toxicity to Raw264.7 macrophages and had inhibitory effects on the morphological variations and production of pro-inflammatory mediators, NO and PGE2 in LPS-stimulated Raw264.7 macrophages. Conclusion: EEPF can be used as a functional material for improving the oral environment through the control of oral microorganisms and for modulating inflammation by inhibiting the production of inflammatory mediators.

• Journal of Dairy Science and Biotechnology
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• v.7 no.1
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• pp.6-19
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• 1989

Twenty-five commercial food grade and alalytical grade lipases were used to study the patterns of release of short-chain free fatty acids (FFA) from milk fat in cheese slurries. Principal component Analysis showed that there were four distinctive groups by the FFA ratios and five groups by the FFA concentrations. However, Average Linkage Cluster Analysis showed that the patterns of FFA released were dependent upon distance defined between groups of lipases. All the lipases tested with both statistical analysis had distinctive specificities in hydrolyzing short-chain FFA from milk fat. Lipases from ruminant-animal origins produced an extremely high ratio (>40%) of butyric acid and a low ratio (<26%) of capric acid to total short chain FFA. Lipases from porcinepancreas and some microbial origins showed balanced production in both bytyric and capric acid. However, most lipases from microbial origins released a high ratio of capric acid but similar ratios to other origin enzymes for short-chain free fatty acids. Ruminant-animal origin lipases produced short-chain FFA much higher in concentration than other lipases. Lipases from porcine pancreas as well as microbial origins showed different concentrations of the fatty acids. Ratios of short-chain FFA in each sample were not significantly changed during incubation periods (4 wk), whereas concentrations of the FFA increased considerably.

• Membrane Journal
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• v.20 no.3
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• pp.173-184
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• 2010

Microbial fuel cell (MFC) is a promising renewable energy source that can generate electrical energy from organic wastes using microbe. This technology has been regarded as a future green alternative energy in that MFC makes use of organic-rich wastewater and also reduces waste sludges as well as produces electricity. To be practically realized, however, achieving higher power density than now is demanded, which may be possible by eliminating various negative factors to act as resistances in MFC operations. For instance, highly activated microbes, highly conductive electrode materials, and fast electron transfer between microbes and electrodes can lead to MFC with high power density. In particular, polymer electrolyte membranes are also a key component for improved MFC performance.

• Preventive Nutrition and Food Science
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• v.15 no.4
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• pp.322-328
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• 2010

This study was conducted to examine the sensory attributes, gingerol content and volatile components of ginger paste resulting from microbial fermentation. In the ginger samples, a total of eighteen attributes were determined to characterize the sensory attributes from descriptive analysis. These eighteen attributes consisted of the following: one appearance, eight odor/aroma, eight taste, and one aftertaste attribute. The ginger fermented using Lactobacillus plantarum produced a ginger aroma and putrid taste, whereas the sample fermented with Lactobacillus brevis showed a decreased ginger aroma and taste, and generated a lemon flavor. A total gingerol content of fresh and fermented ginger was 100.19 mg% and 89.55 mg%, respectively. Sixty-one volatile components in the fresh and fermented ginger were identified, and constituted eight kinds of monoterpenes, twenty-one kinds of sesquiterpenes, eight kinds of oxygenated monoterpenes and nine kinds of oxygenated sesquiterpenes. The most abundant volatile component identified in the fresh ginger was $\alpha$-gingerberine (26.52%), whereas fermented ginger was increased in its alcohol components.

• Journal of Microbiology and Biotechnology
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• v.33 no.10
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• pp.1257-1267
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• 2023

Although rational genetic engineering is nowadays the favored method for microbial strain improvement, building up mutant libraries based on directed evolution for improvement is still in many cases the better option. In this regard, the demand for precise and efficient screening methods for mutants with high performance has stimulated the development of biosensor-based high-throughput screening strategies. Genetically encoded biosensors provide powerful tools to couple the desired phenotype to a detectable signal, such as fluorescence and growth rate. Herein, we review recent advances in engineering several classes of biosensors and their applications in directed evolution. Furthermore, we compare and discuss the screening advantages and limitations of two-component biosensors, transcription-factor-based biosensors, and RNA-based biosensors. Engineering these biosensors has focused mainly on modifying the expression level or structure of the biosensor components to optimize the dynamic range, specificity, and detection range. Finally, the applications of biosensors in the evolution of proteins, metabolic pathways, and genome-scale metabolic networks are described. This review provides potential guidance in the design of biosensors and their applications in improving the bioproduction of microbial cell factories through directed evolution.

• Journal of Microbiology
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• v.42 no.1
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• pp.9-13
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• 2004

Culture-independent approaches, based on 16S rDNA sequences, are extensively used in modern microbial ecology. Sequencing of the clone library generated from environmental DNA has advantages over fingerprint-based methods, such as denaturing gradient gel electrophoresis, as it provides precise identification and quantification of the phylotypes present in samples. However, to date, no method exists for comparing multiple bacterial community structures using clone library sequences. In this study, an automated method to achieve this has been developed, by applying pair wise alignment, hierarchical clustering and principle component analysis. The method has been demonstrated to be successful in comparing samples from various environments. The program, named CommCluster, was written in JAVA, and is now freely available, at http://chunlab.snu.ac.kr/commcluster/.

• Archives of Pharmacal Research
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• v.15 no.1
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• pp.41-47
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• 1992

In order to obtain acetaminophen, a popular analgesic-antipyretic, though microbial p-hydroxylation and N-acetylation of aniline, various Streptomyces strains were screened. Aniline N-acetylation activity was rather ubiquitous but-hydroxylation activity was selective. Microbial conversion pathway of aniline to acetaminophen was considered to be through N-acetylation and p-hydroxylation or vice versa. However, depending on species used, o-hydroxylation and its degradation activity (S. fradiae) and acetaminophen degradation activity (S. coelicolar) were also detected. Among the screened Streptomyces strains, S fradiae NRRL 2702 showed the highest acetanilide p-hydroxylation activity (203% conversion rate). Furthermore, in S. fradiae carbon source and its concentration, phosphate ion concentration and pH of growth medium were found to play the crucial roles in p-hydroxylation activity. Through the proper combination of factors mentioned above, the ten times more activity (26-30% conversion rate) was attained.

• Molecules and Cells
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• v.27 no.2
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• pp.211-215
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• 2009

Toll-like receptors (TLRs) play a critical role in sensing microbial components and inducing innate immune and inflammatory responses by recognizing invading microbial pathogens. Lipopolysaccharide-induced dimerization of TLR4 is required for the activation of downstream signaling pathways including nuclear factor-kappa B ($NF-{\kappa}B$). Therefore, TLR4 dimerization may be an early regulatory event in activating ligand-induced signaling pathways and induction of subsequent immune responses. Here, we report biochemical evidence that 6-shogaol, the most bioactive component of ginger, inhibits lipopolysaccharide-induced dimerization of TLR4 resulting in the inhibition of $NF-{\kappa}B$ activation and the expression of cyclooxygenase-2. Furthermore, we demonstrate that 6-shogaol can directly inhibit TLR-mediated signaling pathways at the receptor level. These results suggest that 6-shogaol can modulate TLR-mediated inflammatory responses, which may influence the risk of chronic inflammatory diseases.