• The Plant Pathology Journal
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• v.38 no.4
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• pp.313-322
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• 2022

Seed-borne pathogens in crops reduce the seed germination rate and hamper seedling growth, leading to significant yield loss. Due to the growing concerns about environmental damage and the development of resistance to agrochemicals among pathogen populations, there is a strong demand for eco-friendly alternatives to synthetic chemicals in agriculture. It has been well established during the last few decades that plant seeds harbor diverse microbes, some of which are vertically transmitted and important for plant health and productivity. In this study, we isolated culturable endophytic bacteria and fungi from soybean seeds and evaluated their antagonistic activities against common bacterial and fungal seed-borne pathogens of soybean. A total of 87 bacterial isolates and 66 fungal isolates were obtained. Sequencing of 16S rDNA and internal transcribed spacer amplicon showed that these isolates correspond to 30 and 15 different species of bacteria and fungi, respectively. Our antibacterial and antifungal activity assay showed that four fungal species and nine bacterial species have the potential to suppress the growth of at least one seed-borne pathogen tested in the study. Among them, Pseudomonas koreensis appears to have strong antagonistic activities across all the pathogens. Our collection of soybean seed endophytes would be a valuable resource not only for studying biology and ecology of seed endophytes but also for practical deployment of seed endophytes toward crop protection.

• 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.

• Korean Journal of Microbiology
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• v.51 no.4
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• pp.407-418
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• 2015

This study is focused on establishing the optimal conditions to enhance the production of antilisterial substances by Lactobacillus paracasei BK57 isolated from Baikkimchi. In addition, the growth and in situ lactic acid and bacteriocin production of this strain were investigated during the manufacture of fresh cheese. And then the efficacy of using Lactobacillus starter as a protective culture to improve the safety of fresh cheese against Listeria monocytogenes KCTC 3569 was estimated. Maximum growth rate and activity of antibacterial substances were obtained in Lactobacilli MRS broth at $37^{\circ}C$ with controlled pH 6.0 after 30 h of incubation under aerobic condition. However, the growth rate and antimicrobial activity of bacteriocin produced in whole milk supplemented with yeast extract (2.0%) as a substrate were lower than those obtained in MRS broth. Live cells and cell-free culture supernatant of BK57 strain were effective in the suppression of L. monocytogenes in milk, whereas the inhibitory of the bacteriocin obtained from BK57 strain was higher in BHI broth than in milk. During storage at $4^{\circ}C$ and $15^{\circ}C$ for 6 days, no significant difference was found in the cell viability and antimicrobial activity of BK 57 strain in fresh cheese. In samples held at two temperatures, there was at least a 15% reduction in the numbers of the pathogen in fresh cheese artificially contaminated with approximately $10^5CFU/ml$ of L. monocytogenes within 6 days. Our results demonstrated the usefulness of L. paracasei BK57 having antilisterial activity as a biopreservative in the cheese making process.

• Journal of Environmental Science International
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• v.25 no.6
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• pp.789-798
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• 2016

Lactic acid bacteria (LAB) are industrially important microorganisms for probiotics. The recent widespread application of LAB for preparation of functional food is attributable to the accumulating scientific evidence showing their beneficial effects on human health. In this study, we isolated and characterized plant-derived LAB that show angiotensin-converting enzyme (ACE) inhibitory and antioxidant activities. The selected strain K2 was isolated from Kimchi, and identified as Lactobacillus plantarum by 16S rRNA gene analysis. The strain grew under static and shaking culture systems. They were also able to grow in different culture conditions like $25^{\circ}C{\sim}37^{\circ}C$ temperature, 4~10 pH range and ~6% NaCl concentration. L. plantarum K2 was highly resistant to acid stress; survival rate of the strain at pH 2.5 and 3 were 80% and 91.6%, respectively. The strain K2 also showed high bile resistance to 0.3% bile bovine and 0.3% bile extract with more than 74% of survival rate. The cell grown on MRS agar plate containing bile extract formed opaque precipitate zones around the colonies, indicating they have bile salt hydrolase activity. The strain showed an inhibitory activity against pathogenic bacteria such as Escherichia coli, Staphylococcus aureus and Listeria monocytogenes; antibacterial activity was probably due to the lactic acid. The K2 strain showed relatively higher autoaggregation values, antihypertensive and antioxidant activities. These results suggest that L. plantarum K2 could be not only applied as a pharmabiotic for human health but also is also starter culture applicable to fermentative products.

• Korean Journal of Clinical Pharmacy
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• v.27 no.3
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• pp.186-194
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• 2017

Objectives: A significant concern has been raised about the emerging resistance that is largely caused by the excessive or inappropriate use of antibacterial agents for viral respiratory infections. This study investigated the trend of respiratory tract infections (RTIs) and the use of antibiotics. Methods: Utilizing the national level health insurance claims data from 2005 to 2008, we examined encounter days, antibiotic use, and the prescription rate for respiratory tract infections including upper respiratory tract infections (URTIs), lower respiratory tract infections (LRTIs), and otitis media in outpatient settings. The antibiotic use was measured as defined daily dose per 1,000 patients per day (DDD/1,000 patients/day). Results: The visit for URTI increased from 141,693,465 in 2005 to 120,717,966 in 2008 and the visit for LRTI decreased from 61,778,718 to 66,930,122. For RTIs, prescription rates of antibiotics decreased from 65.2% to 58.5% for URTIs and 76.9% to 68.3% for LRTIs from 2005 to 2008. The antibiotic use decreased to 20.85 DDD/1,000 patients/day after a significant increase of 22.01 DDD/1,000 patients/day in 2006. Among antibiotics, J01CR had the highest use- 7.93 DDD/1,000 patients/day followed by J01DC of 3.71 DDD/1,000 patients/day and J01FA of 3.2 DDD/1,000 patients/day. One notable trend is that J01FA presented a continuous increase in antibiotic use from 2.3 in 2005 to 3.26 DDD/1,000 patients/day in 2008. Conclusion: The use of antibiotics had poor compliance to guidelines for RTIs. Despite decrease in the use of antibiotics, prescription rates for URTIs were still about 50% indicating that the delayed prescribing antibiotics (or wait-and-see) were not observed.

• Korean Journal of Ichthyology
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• v.29 no.1
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• pp.41-51
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• 2017

To understand the application in farm for the fish aquaculture, we investigated biological and pathological traits on red sea bream Pagrus major which were reared in each copper-alloy net cage and the synthetic fiber net cage for 9 months. Two groups of cage were made and set in Yokji-eup, Tongyoung, Gyeongsangnam-do in size of 25 m in diameter and 10 m of depth. Survival rate of the red sea bream in the rearing copper-alloy net cage and synthetic fiber cage showed 99.75% and 99.70% respectively, there was no significant difference. Daily weight growth rate in each net was shown to 2.13 g/day and 1.65 g/day. Health analysis by blood composition analysis showed a favorable result in the copper-alloy net cage rather than in the synthetic fiber net. Bioaccumulation of heavy metal such as Cu and Zn especially in gonad was higher than other organ. Bioaccumulation of Cu and Zn in the muscle was lower compared to the permitted standard for food safety. Pathogenic infection test discovered Microcotyle tai for parasite, V. alginolyticus and other five species for bacteria. But there was a little bit difference of bacteria infection in copper-alloy net cage and copper-alloy net cage is expected to be has antibacterial effect. Thus, copper-alloy net cage can be applied to farm considering its system stability, recycling, antibiosis and food safety.

• Journal of the korean academy of Pediatric Dentistry
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• v.39 no.4
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• pp.366-372
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• 2012

The aim of this study was to compare two commercial root canal medicaments, ProRoot MTA (Dentsply Tulsa, USA) and OrthoMTA (Bio MTA, Korea), by assessing the antimicrobial effects on three selected species commonly found in root canals of infected teeth, namely Enterococcus faecalis, Fusobacterium nucleatum and Staphylococcus epidermidis. Colonies of these bacteria were treated with varied concentrations of ProRoot MTA or OrthoMTA over different lengths of time. The results are as follows : 50, 25 and 12.5 mg/mL of ProRoot MTA or OrthoMTA did not completely inhibit the growth of E. faecalis, but a decreased growth rate was evident in comparison to the control (p < 0.05). 50 mg/mL of both materials successfully eliminated F. nucleatum during the first 24 hours. Regrowth of microbes after 24 hours, however, indicated a diminished effect of ProRoot MTA whereas OrthoMTA showed its continuously sustained antimicrobial actions (p < 0.05). 50 mg/mL of ProRoot MTA and 50, 25 mg/mL of OrthoMTA exerted their full antibacterial actions against S. epidermidis during the first 24 hours. Although the regrowth of colony was observed after 24 hours, the rate of growth was significantly decreased, approximating a complete inhibition (p < 0.05). The present study revealed that OrthoMTA, recently developed in Korea, had antimicrobial activity higher than ProRoot MTA.

• Korean Journal of Microbiology
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• v.50 no.1
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• pp.27-32
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• 2014

Autophagy is one of the lysosomal degradation pathways to maintain cellular homeostasis. The damaged proteins or organelles are uptaken through extra- and intra-cellular stress, starvation and infected pathogens, subsequently, autophagosomes are fused with lysosomes to break down the molecules. Salmonella enterica serovar Typhimurium (S. Typhimurium), intracellular bacteria, cause acute gastroenteritis and food poisoning. Given that autophagy induced by S. Typhimurium plays an important role in the cells to control the infection, we identify whether the induction of autophagy with rapamycin, chemical inducer of autophagy, before infection regulates S. Typhimurium infection. After treatment of rapamycin or 3-methyladenine (3-MA), autophagy inhibitor, RAW264.7 cells were infected with S. Typhimurium. Pretretment of rapamycin decreased the growth rate of S. Typhimurium in the cells; otherwise, pretreatment of 3-MA increased the growth rate of S. Typhimurium. The expression of autophagy-related genes was significantly increased in the S. Typhimurium-infected cells pretreated with rapamycin. To examine whether induced autophagy by rapamycin control the infection with increase the production of reactive oxygen species (ROS) and nitric oxide (NO), antibacterial radical substrates were measured in infected cells followed by the treatment with either rapamycin or 3-MA. NO production increased in RAW264.7 cells; otherwise, ROS production remained unchanged during the infection. These findings suggest that inducing autophagy with rapamycin reveals antimicrobial activity as producing NO against S. Typhimurium infection in mouse macrophages.

• Journal of Life Science
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• v.24 no.1
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• pp.46-53
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• 2014

Lactobacillus sakei 383, which showed the highest GABA content in fermented soycurd, survived in artificial gastric fluid (pH 3.0) up to 3 h, and the survival rate was 88%. L. sakei 383 was tolerant to bile juice during incubation in MRS broth with 0.3% oxgall, and the survival rate was 99%. The survival ratio of L. sakei 383 was high in media containing less than 6% NaCl. L. sakei 383 produced an antibacterial substance against various pathogens, including Listeria monocytogenes, Bacillus cereus, Staphylococcus aureus, Escherichia coli, and Salmonella typhi. The quality characteristics of soycurd fermented with L. sakei 383 were measured during the fermentation period. The viable cell number reached a peak ($10^{11}CFU/ml$) 36 h after fermentation and then slowly decreased. According to the fermentation time of L. sakei 383, the acidity of soycurd increased and the pH decreased until 12 h, and they were maintained thereafter. The moisture, crude ash, crude protein, crude fat, and crude fiber content was 94.88, 0.22, 2.38, 1.16, and 0.03%, respectively. The content of total and reducing sugar was comparatively higher in the soycurd fermented with L. sakei 383 than in nonfermented soycurd. The essential and nonessential amino acid content was 11.2 and 38.65 mg/100 g.

• Korean journal of applied entomology
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• v.60 no.3
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• pp.263-268
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• 2021

The venom of honeybees (Apis mellifera L.) is used to treat many diseases because of its anti-inflammatory and analgesic effects. Bee venom consists of several biologically active molecules and exhibits remarkable anti-cancer effects. However, biological amines, which exhibit diverse functionality such as anti-inflammatory and antibacterial effects, have not been previously reported in bee venom. In this study, we determined the content of putrescine in bee venom by using ultra-performance liquid chromatography. The specificity, accuracy, and precision of the assay were assessed, and the assay validated. The linearity of the putrescine assay was r ≥ 0.99, indicating a moderate level of putrescine in the bee venom. The limit of detection and limit of quantification were both 0.9 ㎍/mL, while the rate of recovery was 96.4%-99.9%. The relative standard deviation (RSD) of the intra-day precision and inter-day precision of the putrescine assay were 0.16% - 0.23% and 0.09% - 0.36%, respectively, with the RSD ≤ 5% indicating excellent precision. Thus, the linearity, limit of detection, limit of quantification, and recovery rate of the putrescine assay were satisfactory. The analysis of the bee venom showed that the putrescine content was 3.1 ± 0.09 mg/g. This study provides fundamental data on putrescine content in bee venom, which will prove useful in further studies of its bioactivity.