• Journal of Ginseng Research
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• 제38권3호
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• pp.215-219
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• 2014

Background: Biological control of plant pathogens using benign or beneficial microorganisms as antagonistic agents is currently considered to be an important component of integrated pest management in agricultural crops. In this study, we evaluated the potential of Bacillus subtilis strain HK-CSM-1 as a biological control agent against Colletotrichum panacicola. Methods: The potential of B. subtilis HK-CSM-1 as a biological control agent for ginseng anthracnose was assessed. C. panacicola was inoculated to ginseng plants and the incidence and severity of disease was assessed to examine the efficacy of the bacterium as a biological control against C. panacicola. Results: Inoculation of Panax ginseng plants with B. subtilis significantly suppressed the number of disease lesions of C. panacicola and was as effective as the chemical fungicide iminoctadine tris(albesilate). The antifungal activity of B. subtilis against C. panacicola was observed on a co-culture medium. Interestingly, treatment with B. subtilis did not significantly affect the diameter of the lesions, suggesting that the mechanism of protection was through the reduction in the incidence of infection related to the initial events of the infection cycle, including penetration and infection via spore germination and appressorium formation rather than by the inhibition of invasive growth after infection. Conclusion: Our results suggest that B. subtilis HK-CSM-1 can be used as an effective and ecologically friendly biological control agent for anthracnose in P. ginseng.

• 보존과학회지
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• 제25권2호
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• pp.197-206
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• 2009

천연보존제는 주로 식물에서 추출된 항균물질로 만들어지며 부패되기 쉬운 식품의 보존제나 천연화장품, 약품등에 주로 사용되고 있다. 본 연구는 현재 천연화장품의 보존제로 개발되어진 천연보존제를 직물에 처리하여 이것이 섬유문화재 보존에 적용이 가능한지를 탐색하고 평가하는데 그 목적이 있다. 따라서 천연보존제로 처리한 직물의 특성을 알아보고자 천연보존제 1%로 처리한 면직물과 견직물에 대해 실험한 결과 색 및 인장강도의 변화가 극히 미약하고 중성에 가까운 pH를 나타내었으며 우수한 항균성과 항곰팡이성을 가지는 것으로 나타났고 견직물에 피해를 주는 Bacillus cereus에 대해서도 우수한 항균활성을 나타내었다. 또한 섬유문화재에 적용시키기 위한 예비실험으로 출토직물 편을 천연보존제 1%로 처리한 직물로 싸서 72시간 보관한 후 출토직물편의 미생물 실험결과 미생물의 증식이 확연히 준것을 알 수 있었다.

• 한국식품위생안전성학회지
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• 제14권4호
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• pp.319-326
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• 1999

최근 국내에서는 Escherichia coli O157:H7, Listeria monocytogenes등의 미생물에 대한 건강위해성이 강조되면서 미생물 위해성평가에 대한 필요성이 제기되고 있고, U.S.FPA, U.S.DA, FAO/WHO를 비롯한 국제기구 및 외국 유관기관들에서도 미생물 위해성평가 방법을 식품관리에 활용하고자 방법론 연구에 주력하고 있다. 미생물 위험성은 화학물질과 달리 인체건강에 대한 영향이 즉각적이고, 심각하게 나타나 정량적인 위해성평가가 용이하지 않고 유해화학물질과는 다른 평가방법이 요구된다. 식품중 미생물의 위해성평가는 크게 4단계로 구분되는데, 미생물관련질환 추세파악 및 미생물 관련질병에 관한 역학조사 등을 활용하는 위험성확인 단계와 실제 식품원료, 식품가공, 수송, 포장단계 중 식품의 물리적, 화학적 조건에 따른 미생물 변화를 고려하여 식품중 미생물에 대한 노출을 정량화하는 노출평가 단계, 미생물의 용량에 따른 질병발생에 근거하여 용량-반응관계를 규명하는 용량-반응평가 단계, 규명된 모델을 활용하여 모든 평가결과를 통합함으로 위해 도치 예측과 불확실성 분석 등을 수행하는 위해도결정단계로 구성되어 있다. 미생물 용량-반응평가는 크게 비역치(Nonthreshold)와 역치(Threshold) 평가 방법론으로 구분되는데, 비역치 평가방법론은 단일 병원균이 감염을 일으킬 수 있다는 것과 감염을 일으킬 수 있는 확률이 독립적이라는 가정을 전제로 하고, 역치평가방법론은 미생물이 감염을 일으키기 위해서 각기 개별 역치가 존재하는데 어느 정도의 미생물수가 모여 서로 작용해야 독성유발물질을 만들어 낸다는 가정을 전제로 한다. 현재 받아들여지고 있는 비역치 모델로는 Exponential, Beta-poisson, Gompertz, Gamma-weibull 모델 등이 있으며, 역치모델로는 Log-normal, Log-logistic모델 등이 있다. 본 연구에서는 인체 volunteer자료를 활용하여 용량-반응자료를 입력하고 용량-반응자료를 토대로 적합한 수학적 모델을 찾아내어, 선별한 모델의 적합도 검정을 실시하는 방법론 연구를 실시하였으며, 노출평가 자료와 용량-반응평가 결과를 연계하여 위해도를 결정하는 과정에 대해 연구하였다 이 밖에도 모델(Food MicroModel)을 이용하여 식품의 염도, 수분활성도, 온도, pH등의 조건에 따른 미생물의 성장률, 사멸률 등 변화를 예측할 수 있는 방법론 연구를 통해 식품의 최적 보관 조건등을 찾아내는 방법을 습득하였다. 미생물 위해성평가는 외국에서도 아직 초기 연구단계에 있으며 현재로서 사후조사자료인 역학자료보다 건강한 성인남자를 대상으로 한 volunteer 자료를 우선적으로 활용하고 있으나 노약자나 민감그룹에 대한 실험은 현실적으로 불가능하여 동물실험을 이용한 평가방법을 연구중에 있다. 추후 연구방향으로는 국내 volunteer들을 대상으로 한 미생물별 용량-반응결과를 토대로 population sensitivity를 비교할 수 있는 기초자료를 확보함으로써 미생물에 대한 인구집단의 반응 민감성 차이를 비교하고 시료채취 후 즉각적인 실험실적 분석이 가능토록하여 정확한 인체노출평가를 수행함으로써 미생물 위해성평가방법론을 식품미생물관리에 적용하는 것이다.

• Journal of Ginseng Research
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• 제40권2호
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• pp.97-104
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• 2016

Background: Rhizobacteria play an important role in plant defense and could be promising sources of biocontrol agents. This study aimed to screen antagonistic bacteria and develop a biocontrol system for root rot complex of Panax notoginseng. Methods: Pure-culture methods were used to isolate bacteria from the rhizosphere soil of notoginseng plants. The identification of isolates was based on the analysis of 16S ribosomal RNA (rRNA) sequences. Results: A total of 279 bacteria were obtained from rhizosphere soils of healthy and root-rot notoginseng plants, and uncultivated soil. Among all the isolates, 88 showed antagonistic activity to at least one of three phytopathogenic fungi, Fusarium oxysporum, Fusarium solani, and Phoma herbarum mainly causing root rot disease of P. notoginseng. Based on the 16S rRNA sequencing, the antagonistic bacteria were characterized into four clusters, Firmicutes, Proteobacteria, Actinobacteria, and Bacteroidetesi. The genus Bacillus was the most frequently isolated, and Bacillus siamensis (Hs02), Bacillus atrophaeus (Hs09) showed strong antagonistic activity to the three pathogens. The distribution pattern differed in soil types, genera Achromobacter, Acidovorax, Brevibacterium, Brevundimonas, Flavimonas, and Streptomyces were only found in rhizosphere of healthy plants, while Delftia, Leclercia, Brevibacillus, Microbacterium, Pantoea, Rhizobium, and Stenotrophomonas only exist in soil of diseased plant, and Acinetobacter only exist in uncultivated soil. Conclusion: The results suggest that diverse bacteria exist in the P. notoginseng rhizosphere soil, with differences in community in the same field, and antagonistic isolates may be good potential biological control agent for the notoginseng root-rot diseases caused by F. oxysporum, Fusarium solani, and Panax herbarum.

• 한국유기농업학회지
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• 제23권1호
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• pp.77-89
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• 2015

본 연구는 수박 과실썩음병의 원인균인 Acidovorax avenae subsp. citrulli 균에 대해서 항균활성을 갖는 친환경 유기농자재를 개발할 목적으로 약용식물 133종을 대상으로 진행되었다. 이들 133종 약용식물의 MeOH 추출물에 대한 bioassay를 통해 항균 활성을 검정한 결과 청피(Citrus unshiu Markovich) 추출물에서 강한 항균활성을 보였다. 청피(Citrus unshiu Markovich)로부터 항균활성물질을 구명하고자 용매분획을 하였고, 용매분획 중에서 hexane fraction이 가장 강한 활성을 나타내었다. Hexane fraction을 GC-MS로 분석하여 chromatogram상의 각각의 peak에 해당하는 mass spectrum과 Wiley library를 비교하여 profiling 한 결과, essential oil인 d-limonene, ${\gamma}$-terpinene, ${\beta}$-linalool, terpineol과 지방산인 palmitic acid, 9,12-octadecadienoic acid, linolenic acid 그리고 steroid 화합물인 stigmasterol이 검출되었다. 이들 검출화합물 중에서 항균 활성물질로 추정되는 d-limonene, ${\gamma}$-terpinene, ${\beta}$-linalool, terpineol의 항균 활성을 검정하기 위해 표준품을 사용하여 bioassay한 결과 두 화합물 d-limonene, ${\gamma}$-terpinene에서 높은 항균활성을 보였다. 따라서 본 연구를 통해 청피로부터 분리한 d-limonene과 ${\gamma}$-terpinene 화합물이 항균 활성물질인 것을 구명하였다. 항균력이 강한 청피 추출물 또는 d-limonene과 ${\gamma}$-terpinene을 주성분으로 하는 추출물을 수박 과실썩음병에 대한 친환경 방제용 자제로 개발이 가능할 것으로 판단되었다.

• Journal of Ginseng Research
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• 제41권3호
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• pp.353-360
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• 2017

Background: Endophytic fungi play an important role in balancing the ecosystem and boosting host growth. In the present study, we investigated the endophytic fungal diversity of healthy Panax notoginseng and evaluated its potential antimicrobial activity against five major phytopathogens causing root-rot of P. notoginseng. Methods: A culture-dependent technique, combining morphological and molecular methods, was used to analyze endophytic fungal diversity. A double-layer agar technique was used to challenge the phytopathogens of P. notoginseng. Results: A total of 89 fungi were obtained from the roots, stems, leaves, and seeds of P. notoginseng, and 41 isolates representing different morphotypes were selected for taxonomic characterization. The fungal isolates belonged to Ascomycota (96.6%) and Zygomycota (3.4%). All isolates were classified to 23 genera and an unknown taxon belonging to Sordariomycetes. The number of isolates obtained from different tissues ranged from 12 to 42 for leaves and roots, respectively. The selected endophytic fungal isolates were challenged by the root-rot pathogens Alternaria panax, Fusarium oxysporum, Fusarium solani, Phoma herbarum, and Mycocentrospora acerina. Twenty-six of the 41 isolates (63.4%) exhibited activity against at least one of the pathogens tested. Conclusion: Our results suggested that P. notoginseng harbors diversified endophytic fungi that would provide a basis for the identification of new bioactive compounds, and for effective biocontrol of notoginseng root rot.

• Journal of Microbiology and Biotechnology
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• 제15권6호
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• pp.1164-1169
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• 2005

Characteristics of sophorolipid and rhamnolipid were evaluated as antifungal agents against plant pathogenic fungi. Eight percent of mycelial growth of plant pathogen (Phytophthora sp. and Pythium sp.) was inhibited by 200 mg/l of rhamnolipid or 500 mg/l of sophorolipid, and zoospore motility of Phytophthora sp. decreased by $90\%$ at 50 mg/l of rhamnolipid and $80\%$ at 100 mg/l of sophorolipid. The effective concentrations for zoospore lysis were two times higher than those of zoospore motility inhibition. The highest zoospore lysis was observed with Phytophthora capsici; $80\%$ lysis at 100 mg/I of di-rhamnolipid or lactonic sophorolipid, showing the dependency of structure on the lysis. In the pot test, the damping-off disease incidence ratio decreased to $42\%\;and\;33\%$ of control value at 2,000 mg/l sophorolipid and rhamnolipid, respectively. These results showed the potential of microbial glycolipid biosurfactants as an effective antifungal agent against damping-off plant pathogens.

• 한국응용과학기술학회지
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• 제25권4호
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• pp.477-484
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• 2008

It is inevitable to use chemical germicidal agents like paraben, imidazolidinyl urea and phenoxyethanol to preserve the emulsions which is usually used in cosmetics. Although these chemical preservatives are good enough to reduce the microbiological contamination, they are irritative, allergenic to the skin. Several kinds of polyols are used in cosmetics as moisturizer and solvent. In this study, we evaluate the effects of polyols on anti-microbial activities, safety and resistant index. MIC(minimal inhibitory concentration) of polyols determined against 6 germs including Staphylococcus aureus. The order of MIC was PG $\cong$ DPG $\cong$ 1,3BG > HG > 1,2-PD > 1,2-HD $\cong$ 1,2-OD. The $2{\sim}3\;wt%$ of 1,2-HD(hexanediol) shows good anti-microbial effects in emulsions without allergenic response. Resistant index of 1,2-HD was less than 2 and this value was smaller than that of chemical preservatives. The mechanism of antimicrobilogical effect might be disturb the membrane of germs by investigating using electron microscope. Added to that, using this paradigm, low preservative contents, paraben-free system, and even preservative-free systems can be expected from these results.

• ETRI Journal
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• 제32권3호
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• pp.440-446
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• 2010

Array-based gas sensors now offer the potential of a robust analytical approach to odor measurement for medical use. We are developing a fast reliable method for detection of microbial infection by monitoring the headspace from the infected wound. In this paper, we present initial results obtained from wound-state monitoring for burn patients using an electronic nose incorporating an automated solid-phase microextraction (SPME) desorption system to enable the system to be used for clinical validation. SPME preconcentration is used for sampling of the headspace air and the response of the sensor module to variable concentrations of volatiles emitted from SPME fiber is evaluated. Gas chromatography-mass spectrometry studies prove that living bacteria, the typical infectious agents in clinical practice, can be distinguished from each other by means of a limited set of key volatile products. Principal component analysis results give the first indication that infected patients may be distinguished from uninfected patients. Microbial laboratory analysis using clinical samples verifies the performance of the system.

• Biomolecules & Therapeutics
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• 제29권3호
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• pp.263-267
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• 2021

Periodontal disease is primarily associated with bacterial infection such as dental plaque. Dental plaque, an oral biofilm harboring a complex microbial community, can cause various inflammatory reactions in periodontal tissue. In many cases, the local bacterial invasion and host-mediated immune responses lead to severe alveolar bone destruction. To date, plaque control, non-surgical, and surgical interventions have been the conventional periodontal treatment modalities. Although adjuvant therapies including antibiotics or supplements have accompanied these procedures, their usage has been limited by antibiotic resistance, as well as their partial effectiveness. Therefore, new strategies are needed to control local inflammation in the periodontium and host immune responses. In recent years, target molecules that modulate microbial signaling mechanisms, host inflammatory substances, and bone immune responses have received considerable attention by researchers. In this review, we introduce three approaches that suggest a way forward for the development of new treatments for periodontal disease; (1) quorum quenching using quorum sensing inhibitors, (2) inflammasome targeting, and (3) use of FDA-approved anabolic agents, including Teriparatide and sclerostin antibody.