• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2003.09a
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• pp.152-157
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• 2003

Diesel-contaminated soils were ozonated for different times (0 - 900 min) and incubated for 9 wk to monitor petroleum hydrocarbons (PH)-degradative potential of indigenous microorganisms in the soils. Increased ozonation time decreased not only concentration of PH but also number of microorganisms in the soils. Microorganisms in the ozonated soils increased during 9-wk incubation as monitored by culture- and nonculture-based methods. Higher (1-2 orders of magnitude) cell number was observed by quantitative analysis of soil DNA using probes detecting genes encoding 165 rRNA(rrn), naphthalene dioxygenase (nahA), toluene dioxygenase (todC), and alkane hydroxylase (alkB) than microbial abundance estimated by culture-based methods. Such PH-degraders were relatively a few or under detection limit in 900-min ozonated soil. Further PH-removal observed during the incubation period supported the presence of PH-degraders in ozonated soils. Highest reduction (25.4%) of total PH (TPH) was observed in 180-min ozonated soil white negligible reduction was shown in 900-min ozonated soil during the period, resulting in lowest TPH-concentration in 180-min ozonated soil among the ozonated soils. Microbial community composition in 9-wk incubated soils revealed slight difference between 900-min ozonated and unozonated soils as analyzed by whole cell hybridization using group-specific rRNA-targeted oligonucleotides. Results of this study suggest that appropriate ozonation and subsequent biodegradation by indigenous microorganisms may be a cost-effective and successful remediation strategy for PH-contaminated soils.

• 한국생물공학회:학술대회논문집
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• 2002.04a
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• pp.355-358
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• 2002

In this study, we have tried to find the maximum microbial efficiency at the various dissolved oxygen (DO) concentration conditions in the treatment of pharmaceutical wastewater. Experiments of activated sludge process were performed to examine the relation between microbial activity and DO concentration in a continuous bioreactor. The reduction rate of COD (chemical oxygen demand) was low at the DO concentration between 0 ppm and 1.0 ppm, but it went higher and showed maximum between 1.5 ppm and 3.0 ppm. Then the COD reduction rate was quickly decreased above the DO concentration of 3.0 ppm.

• Food Science and Preservation
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• v.6 no.3
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• pp.276-280
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• 1999

To maintain the quality characteristics of vegetables, produce was dipped in Korean medical herb extracts (KMHE) such as Rheum palmatum L. or Coptis chinensis Franch with different concentration. Dipping in 500 ppm KMHE solution was suitable for the reduction or microbial load on cucumber, and 100 ppm KMHE solution was appropriate for others. Dipping time was suitable for produce about 10 minutes, and the temperature of dining solution had a limited effect cm the microbial load reduction. Antimicrobial activity of Coptis chinensis Franch and Rheum palmatum L. was maintained for cucumber and zucchini wrapped with polyvinylchloride film during storage at 10$^{\circ}C$.

• Bulletin of the Korean Chemical Society
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• v.33 no.11
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• pp.3581-3588
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• 2012

A new series of acyclic mononuclear gadolinium(III) complexes have been prepared by Schiff-base condensation derived from 5-methylsalicylaldehyde, diethylenetriamine, tris(2-aminoethyl) amine, triethylenetetramine, N,N-bis(3-aminopropyl)ethylene diamine, N,N-bis(aminopropyl) piperazine, and gadolinium nitrate. All the complexes were characterized by elemental and spectral analyses. Electronic spectra of the complexes show azomethine (CH=N) within the range of 410-420 nm. The fluorescence efficiency of Gd(III) ion in the cavity was completely quenched by the higher chain length ligands. Electrochemical studies of the complexes show irreversible one electron reduction process around -2.15 to -1.60 V The reduction potential of gadolinium(III) complexes shifts towards anodic directions respectively upon increasing the chain length. The catalytic activity of the gadolinium(III) complexes on the hydrolysis of 4-nitrophenylphosphate was determined. All gadolinium(III) complexes were screened for antibacterial activity.

• The Korean Journal of Food And Nutrition
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• v.17 no.4
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• pp.436-441
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• 2004

As the production of agricultural products showing high quality and environmental safety is required increasingly these days, it is really necessary to study on technology for producing agricultural products which are safe microbiologically. Among several sanitizing reagents contacted easily, we investigated the most effective and useful method for reducing microorganisms by sanitizer treatment. From this study, it was showed that treatment of 3% hydrogen peroxide solution over 1 minute, which decreased microbiological level less than one tenth of natural state(no sanitizer treatment) in all microorganisms tested, was the most effective sanitizing method to green vegetables, especially raw lettuce used in this study, for reducing microorganisms. By utilizing this sanitizing method in farming step, the improvement of safety and added value of agricultural products, especially raw green vegetables, is expected.

• Development and Reproduction
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• v.26 no.4
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• pp.145-153
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• 2022

The gut microbiota is involved in the maintenance of physiological homeostasis and is now recognized as a regulator of many diseases. Although germ-free mouse models are the standard for microbiome studies, mice with antibiotic-induced sterile intestines are often chosen as a fast and inexpensive alternative. Pathophysiological changes in the gut microbiome have been demonstrated, but there are no reports so far on how such alterations affect the bacterial composition of the uterus. Here we examined changes in uterine microbiota as a result of gut microbiome disruption in an antibiotics-based sterile-uterus mouse model. Sterility was induced in 6-week-old female mice by administration of a combination of antibiotics, and amplicons of a bacteria marker gene (16S rRNA) were sequenced to decipher bacterial community structures in the uterus. At the phylum-level, Proteobacteria, Firmicutes, and Actinobacteria were found to be dominant, while Ralstonia, Escherichia, and Prauserella were the major genera. Quantitative comparisons of the microbial contents of an antibiotic-fed and a control group revealed that the treatment resulted in the reduction of bacterial population density. Although there was no significant difference in bacterial community structures between the two animal groups, β-diversity analysis showed a converged profile of uterus microbiotain the germ-free model. These findings suggest that the induction of sterility does not result in changes in the levels of specific taxa but in a reduction of individual variations in the mouse uterus microbiota, accompanied by a decrease in overall bacterial population density.

• The Plant Pathology Journal
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• v.25 no.3
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• pp.263-269
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• 2009

Bacterial wilt, Fusarium wilt and Foot rot caused by Ralstonia solanacearum, Fusarium oxysporum, and Phytophthora capsici respectively, continue to be severe problems to tomato, potato and black pepper growers in Vietnam. Three bio-products, Bacillus vallismortis EXTN-1 (EXTN-1), Bacillus sp. and Paenibacillus sp. (ESSC) and Bacillus substilis (MFMF) were examined in greenhouse bioassay for the ability to reduce bacterial wilt, fusarium wilt and foot rot disease severity. While these bio-products significantly reduced disease severities, EXTN-1 was the most effective, providing a mean level of disease reduction 80.0 to 90.0% against bacterial wilt, fusarium wilt and foot rot diseases under greenhouse conditions. ESSC and MFMF also significantly reduced fusarium wilt, bacterial wilt and foot rot severity under greenhouse conditions. Bio-product, EXTN-1 with the greatest efficacy under greenhouse condition was tested for the ability to reduce bacterial wilt, fusarium wilt and foot rot under field condition at Song Phuong and Thuong Tin locations in Ha Tay province, Vietnam. Under field condition, EXTN-1 provided a mean level of disease reduction more than 45.0% against all three diseases compared to water treated control. Besides, EXTN-1 treatment increased the yield in tomato fruits 17.3% than water treated control plants.

• Journal of Microbiology and Biotechnology
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• v.26 no.9
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• pp.1542-1550
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• 2016

This is the first report that paromomycin, an antibiotic derived from Streptomyces sp. AG-P 1441 (AG-P 1441), controlled Phytophthora blight and soft rot diseases caused by Phytophthora capsici and Pectobacterium carotovorum, respectively, in chili pepper (Capsicum annum L.). Chili pepper plants treated with paromomycin by foliar spray or soil drenching 7 days prior to inoculation with P. capsici zoospores showed significant (p < 0.05) reduction in disease severity (%) when compared with untreated control plants. The disease severity of Phytophthora blight was recorded as 8% and 50% for foliar spray and soil drench, respectively, at 1.0 ppm of paromomycin, compared with untreated control, where disease severity was 83% and 100% by foliar spray and soil drench, respectively. A greater reduction of soft rot lesion areas per leaf disk was observed in treated plants using paromomycin (1.0 μg/ml) by infiltration or soil drench in comparison with untreated control plants. Paromomycin treatment did not negatively affect the growth of chili pepper. Furthermore, the treatment slightly promoted growth; this growth was supported by increased chlorophyll content in paromomycin-treated chili pepper plants. Additionally, paromomycin likely induced resistance as confirmed by the expression of pathogenesis-related (PR) genes: PR-1, β-1,3-glucanase, chitinase, PR-4, peroxidase, and PR-10, which enhanced plant defense against P. capsici in chili pepper. This finding indicates that AG-P 1441 plays a role in pathogen resistance upon the activation of defense genes, by secretion of the plant resistance elicitor, paromomycin.

• Korean journal of food and cookery science
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• v.20 no.6 s.84
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• pp.589-597
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• 2004

This study was conducted to investigate the effects of various kinds of electrolyzed and chlorinated waters on the sensory and microbiological qualities of fresh-cut lettuce and to determine the most suitable electrolyzed water for the vegetable dishes, without heat treatment, at institutional foodservices. The sensory evaluation resulted in higher scores on the 1st-day of storage for the EW-1 (diaphragm type 1) and EW-3 (non-diaphragm type) compared to that for EW-2 (diaphragm type 2), with regard to their appearance, discoloration, texture, taste and overall acceptability characteristics. However, over time, EW-3 ranked highest, with a score of 8.00 (very like), on the 4th-day of storage, which maintained the highest level up to the 7th-day of storage, at which time the score was 7.00 (fairly like). The CW (chlorinated Water) had a significantly lower score, due to the smell of chlorine, although there was no concern with relation to chlorine residue from the electrolyzed waters. Microbial examinations of the total plate count revealed that immersing lettuce into EW-3 brought about l/3,000 to 1/30,000 reductions in the microbial counts of the TW treatment or untreated samples for up to seven days of storage. The CW treatment gave a 1/10 reduction in the microbial counts compared with the TW (tap water) treatment. The coliform bacterial counts also showed similar trends to those of the total plate count values. With regards to the psychotropic bacterial count, EW-3 was able to result in as much as a 1/30,000 reduction in the initial counts. As vegetable dishes, such as salad, can not be heat-sterilized, the utilization of EW-3 for the preparation of vegetable dishes without heat treatment will be an excellent choice to improve the critical control point in production state as a new effective means for sanitizing management.

• Microbiology and Biotechnology Letters
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• v.7 no.4
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• pp.197-204
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• 1979

Chlorine alone was not effective in reducing the numbers of microorganisms on the chicken carcasses. The chlorine in addition to succinic acid, in which the carcasses were immersed for 30 minutes succeeded in reducing the numbers of microorganisms on the chicken skin. Chicken drumsticks treated with 200 ppm NaOCl plus 0.5％ succinic acid stored at 5$^{\circ}C$ showed a little reduction in microbial quantity for approximately 2 days, but the microbial load increased thereafter to the point of indicating organoleptic spoilage in approximately 7 days. This method extended the shelf life of chicken by 2 days.