• 한국작물학회지
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• 제40권4호
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• pp.487-493
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• 1995

본 실험은 콩나물 재배과정 중에 일어나는 부패문제를 해결하기 위하여 사용이 허가된 산성 식품 첨가제들을 대상으로 그 이용 가능성을 찾아보고자 수행되었다. 다소 노화된 은하콩을 재료로 콩나물 배축의 부패에 관여하는 균(부패균)을 순수 분리하여 그 특성을 조사하였고, propionic acid 등 8가지 약제처리가 부패균의 증식 억제효과를 인왕배지상에서 검토하였다. 또한 1% 이하의 약액처리가 콩나물 발아와 유묘생장에 미치는 영향을 조사하여 약해유발의 가능성도 검토하였으며 그 결과들을 요약하면 다음과 같다. 1. 부패균으로 확인된 3종류의 균계를 대상으로 Gram stain등 8가지 미생물학적 검정을 통하여 분석한 결과 상호 약간의 특성 차이는 있었으나 Pseudomonas속의 균계로 판단되었으며, 분리된 곰팡이류 중에는 부패균이 없었다. 2. 5% 이상의 농도에서는 공시약제 중 sodium hypochlorite의 부패균 증식억제 효과가 가장 컸으나 발아를 극심하게 저해하여 실용성이 없다고 판단되었다. 3. Propionic acid, acetic acid, calcium propionate, sodium propionate등의 약제 효과가 큰 것으로 나타났는데 propionic acid와 acetic acid의 효과가 상대적으로 더 뚜렷하였다. 4. Propionic acid, acetic acd, calcium propionate, sodium propionate 등의 선발된 4가지 약제는 1.0% 및 그 이하의 농도에서도 다소의 부패균 증식억제 효과가 나타나 부패경감제로서의 충분한 이용 가능성을 보였다. 5. 1%이하의 용액에 콩종자를 침지처리 하였을 때 무처리에 비해 선발된 4가지 약제처리에서 모두 발아율, 초기생육 및 비정상발아 개체율에서 차이를 나타내지 않아 약해는 문제시 되지 않을 것으로 판단되었다.

• 대한미생물학회지
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• 제16권1호
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• pp.19-28
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• 1981

The Pseudomonas infection has been increased in incidence and suspected as a cause of opportunistic pathogen. Protease and elastase produced by Pseudomonas aeruginosa are reported to be closely associated with pathogenicity of Pseudomonas aeruginosa. We examined, in this work, the relationship between production of exoenzyme of Pseudomonas aeruginosa and susceptibility to antimicrobial agents in view of possible application to the management of Pseudomonas infection. 1. In 295 Pseudomonas aeruginosa isolated from clinical specimens, 34.6% were from pus, 20.7% from sputum, 15.6% from wound including burn sites and 12.9% from urine. 2. Distribution of protease and elastase production by clinically isolated Pseudomonas aeruginosa, showed that protease and elastase producing strains were 83.1%, protease producing strains were 7.5%, elastase producing strains were 2.0%, and non producing strains were 7.5%. 3. MIC(minimum inhibitory concentration) peak for tetracycline and chloramphenicol were observed at 25mcg/ml and 200mcg/ml respectively, but there were no Pseudomonas aeruginosa which correspond to MIC peak, 6.25mcg/ml. Gentamicin of aminoglycosides was highly susceptible to Pseudomonas aeruginosa clinically isolated from pus, sputum and wound sites, but susceptible to isolates from nasal discharge and urine. Regarding MIC peak of carbenicillin, 100mcg/ml, 81.8% of Pseudomonas aeruginosa were from urine, 54.8% from wound including burn sites, 52.7% from pus, and 50.8% from sputum. 4. Enzyme producing strains showed no susceptibility to kanamycine and carbenicillin at low concentration, but protease producing strains tend to resistant to antimicrobial agents.

• Journal of Ginseng Research
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• 제5권1호
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• pp.73-84
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• 1981

Effect of environmental factors and host on the growth and outbreak of various ginseng diseases was reviewed Environmental lectors included hydrogen ion concentration, moisture content, temperature, nutrition, and microbiol populations. Age of the ginseng plants in relation to several ginseng disease occurrence was also included in order to formulate the effective control measure for ginseng diseases. Damping-off caused by Rhizoctonia, Pythium, and Phytophthora, greymold by Botrytis, sclerotinia by Scleretinia, and phytophthora blight caused by Phytophthora were usually prevalent during the early growing season of ginseng when temperature is below 20$^{\circ}C$, while anthrac se caused by Colletotrichum, alternaria blight by Alternaria, and bacterial soft rot by Erwinia were so during the latter growing season when temperature is above 25$^{\circ}C$. However, the root rot incited by Fnarium and Cylindrocarpon caused severe damages throughout the growing season. Growth range of the temperature for a pathogen was highly related to the corresponding disease outbreak. Hydrogen ion concentration was highly related to the outbreak of sclerotinia, root rot, and red rot. Most severe outbreak of those diseases where the soil acidity was pH 4.7, pH 6.5- 7.5, and pH6.0-6.5, respectively. Nitrogen content in the soil was also related to outbreak of root rot and red rot. More red rot occurred where NH,-nitrogen is above 30 ppm and more root rot obtained when excessive nitrogen fertilizer applied. Yellow necrosis apparently was related to magnesium especially its ratio with potassium or calcium content in a soil. Fusarium Population showed significant .relations to missing rate of ginseng Plants in a Implanting ginseng field, while that of total bacteria showed similar relations in all ginseng field, However, in six year old ginseng fields, the more the Streptomyces population was, the less the Fusarium obtained. Consequently, less missing rate observed in a field where Streptomyces population was high. Damping-off, root rot, Rhytophthor a blight were mose severe on the nursery and on 2-3 years old ginseng plants, whereas sclerotinia, and grey cod, alteraria blight, anthracnose were severe on 4-6 years old ginseng plants. Root rot caused by Fusarium and Erwinia, however, was also severe regardless of the age of the plants when the roots were injured. Therefore, for the effective control of ginseng root rot most careful control of the disease during the early year should be rendered.

• 약학회지
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• 제55권3호
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• pp.227-233
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• 2011

We previously reported the protein isolated from Coptidis Rhizoma (CRP), which has antifungal activity against a fungal pathogen, Candida albicans. In the current study, we investigated what portion in the CRP is responsible for the antifungal activity. For the investigation, the CRP was fractionated on a Shepadex G-50 column. Data resulting from the fractionation, seven fractions were obtained. Fractions (Fr.) I, II, and III eluted initially from the column showed no inhibitory effect on the growth of C. albicans, whereas Fr. IV, V, and VI eluted later revealed inhibition of the growth, and Fr. IV and VI showed potent antifungal activity by broth susceptibility analysis. However, Fr. VI was contained in the CRP more than Fr. IV, which led us to select the VI for the following experiments. In a murine model of a subcutaneous candidiasis caused by C. albicans, the Fr. VI displayed a therapeutic effect on nude mice pretreated with anti-neutrophil monoclonal antibody (RB68C5) and then infected subcutaneously with live C. albicans. At day 16, these mice were healed almost up to 78% of the infected area when compared to infected area of control nude mice that received diluent (Dulbecco's Phosphate-Buffered Saline; DPBS), instead of the Fr. VI (P<0.01). The Fr. VI blocked hyphal formation from blastoconidial form of C. albicans (P<0.01), which might prevent penetration of hyphae to the deeper site of skin and thus helps the healing. In the ionic strength test, the effect of Fr. was influenced by $Ca^{2+}$ ion just like other known antimicrobial peptides, but the influence was affected at an extremely high concentration such as 500 mM. Thus, such ion-concentration is considered to be meaningless in the clinical situation. Considering all data together, Coptidis Rhizoma is appeared to produce an antimicrobial peptide that has therapeutic effect on subcutaneous infection caused by C. albicans.

• 한국식품과학회지
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• 제37권4호
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• pp.671-677
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• 2005

최근 식중독 발생이 대형화됨에 따라 식중독 예방과 식품의 위생적 생산관리를 위하여 식품제조시설에서의 살균소독제 사용 요구가 증가되는 추세이다. 또한 미국 FDA에서는 E. coli와 S. aureus에 대하여 $5\;log_{10}$ CFU/mL의 균수를 감소시키는 화학제제를 살균소독제로 인정하고 있다. 국내에서 유통되는 11종의 살균소독제와 5가지 식품 위해 미생물인 P. aeruginosa, E. coli, S. typhimurium, S. aureus, E. hirae를 대상으로 살균소독제의 유효성을 평가한 결과 현재 시중에서 유통되고 있는 살균소독제 중 자몽추출물과 chlorine를 원료로 사용하는 일부 품목의 경우 법적허용기준인 $5\;log_{10}$ CFU/mL의 살균효과에 미치지 못하는 것으로 판단되었다.

• Journal of Biosystems Engineering
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• 제43권4호
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• pp.401-409
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• 2018

Decay of fruit is one of the greatest issues in fruit storage. Purpose: In this study, citrus sterilization was performed to evaluate a dry sterilization method using an atmospheric-pressure nonthermal plasma treatment based on a dielectric-barrier discharge technique. Methods: Citrus samples were stored under four different environmental conditions as follows: group A had cold storage with plasma treatment with a temperature of $6.2{\pm}1.0^{\circ}C$ and relative humidity (RH) of $93.4{\pm}8.2%$, group B had ambient-temperature storage with $22.9{\pm}2.3^{\circ}C$ and $82.1{\pm}4.5%$ RH, group C ambient-temperature storage with plasma treatment with $25.3{\pm}2.2^{\circ}C$ and $90.0{\pm}2.8%$ RH, and group D had cold storage with $5.7{\pm}1.0^{\circ}C$ and $93.4{\pm}6.5%$ RH. Results: As a result of citrus surface sterilization by plasma treatment, treatment groups A and C together showed an average of 16.1 CFU/mL of mold colonies, while control groups B and D showed an average of $2.2{\times}10^2CFU/mL$ or approximately 13 times greater than the treatment groups. Regarding the mean concentration of aerobic bacteria colonies, the treatment groups (A and C) and control groups (B and D) showed an average of 7.1 CFU/mL and $1.9{\times}10^3CFU/mL$, respectively. This is approximately a 270-fold difference in the concentration of pathogen colonies between treatment and control groups. Conclusions: The results showed the potential of nonthermal plasma treatment for citrus storage in enhancing storage duration and quality preservation.

• Journal of Ginseng Research
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• 제48권2호
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• pp.229-235
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• 2024

Background: Plant health is directly related to the change in native microbial diversity and changes in soil health have been implicated as one of the main cause of root rot. However, scarce information is present regarding allelopathic relationship of Panax notoginseng root exudates and pathogenic fungi Fusarium oxysporum in a continuous cropping system. Methods: We analyzed P. notoginseng root exudate in the planting soil for three successive years to determine phenolic acid concentration using GC-MS and HPLC followed by effect on the microbial community assembly. Antioxidant enzymes were checked in the roots to confirm possible resistance in P. notoginseng. Results: Total 29 allelochemicals in the planting soil extract was found with highest concentration (10.54 %) of p-hydroxybenzoic acid. The HPLC showing a year-by-year decrease in p-hydroxybenzoic acid content in soil of different planting years, and an increase in population of F. oxysporum. Moreover, community analysis displayed negative correlation with 2.22 mmol. L^-1 of p-hydroxybenzoic acid correspond to an 18.1 % population of F. oxysporum. Furthermore, in vitro plate assay indicates that medium dose of p-hydroxybenzoic acid (2.5-5 mmol. L^-1) can stimulate the growth of F. oxysporum colonies and the production of macroconidia, as well as cell wall-degrading enzymes. We found that 2-3 mmol. L^-1 of p-hydroxybenzoic acid significantly increased the population of F. oxysporum. Conclusion: In conclusion, our study suggested that p-hydroxybenzoic acid have negative effect on the root system and modified the rhizosphere microbiome so that the host plant became more susceptible to root rot disease.

• Journal of Microbiology and Biotechnology
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• 제34권8호
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• pp.1671-1679
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• 2024

Aspergillus flavus, the primary mold that causes food spoilage, poses significant health and economic problems worldwide. Eliminating A. flavus growth is essential to ensure the safety of agricultural products, and extracellular compounds (ECCs) produced by Bacillus spp. have been demonstrated to inhibit the growth of this pathogen. In this study, we aimed to identify microorganisms efficient at inhibiting A. flavus growth and degrading aflatoxin B₁. We isolated microorganisms from soil samples using a culture medium containing coumarin (CM medium) as the sole carbon source. Of the 498 isolates grown on CM medium, only 132 bacterial strains were capable of inhibiting A. flavus growth. Isolate 3BS12-4, identified as Bacillus siamensis, exhibited the highest antifungal activity with an inhibition ratio of 43.10%, and was therefore selected for further studies. The inhibition of A. flavus by isolate 3BS12-4 was predominantly attributed to ECCs, with a minimum inhibitory concentration and minimum fungicidal concentration of 0.512 g/ml. SEM analysis revealed that the ECCs disrupted the mycelium of A. flavus. The hydrolytic enzyme activity of the ECCs was assessed by protease, β-1,3-glucanase, and chitinase activity. Our results demonstrate a remarkable 96.11% aflatoxin B1 degradation mediated by ECCs produced by isolate 3BS12-4. Furthermore, treatment with these compounds resulted in a significant 97.93% inhibition of A. flavus growth on peanut seeds. These findings collectively present B. siamensis 3BS12-4 as a promising tool for developing environmentally friendly products to manage aflatoxin-producing fungi and contribute to the enhancement of agricultural product safety and food security.

• Journal of Microbiology and Biotechnology
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• 제10권3호
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• pp.429-433
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• 2000

Giardia lamblia, a human pathogen causing outbreaks of diarrhea, recently became a focus of great concerns in the fields of both medical and environmental microbioloty. To develop the experimental tools to study giardiasis, encystation, one of the major processes in its life cycle, was reconstituted by inducing an axenic culture of a flagellated form of G. lamblia into a cyst from under high concentration of bile and alkaline pH condition. The successful induction was confirmed by Northern analysis of resulting increased expression of the CWPl gene encoding the cyst wall protein 1. An examination of the encystation process with SEM (scanning electron microscopy) and TEM (transmission electron microscopy) revealed that the trophozoite, a flagellate with a bilateral symmetry, was transformed to a cyst form with an oval-shape and defined filamentous wall. The encystation was found to cause a disappearance of the flagella and an invagination of the adhesive disc. An extensive formation of rER (rough endoplasmic reticulum) was observed after 24h of induction, indication an active synthesis and export of proteins during this process. The vital staining of the invitro-induced systs showed that most cysts maintained their viability.

• 동아시아식생활학회지
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• 제16권2호
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• pp.199-206
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• 2006

This study was designed to investigate the effect of medicinal herb extract on the antioxidant and antimicrobial activities against Helicobacter pylori, which is known as a ulcerogenic pathogen. The concentration of total phenolic compound of Scutellaria baicalensis(13.14%) was highest among water extracts and that of Ulmus parvifolia(15.12%) was highest among the ethanol extracts. The antioxidant activity of the water extract of Scutellaria baicalensis and of the ethanol extract of Ulmus parvifolia were 91.00% and 65.03%, respectively, in DPPH assay. The antioxidant activity of the water extract of Scutellaria baicalensis and of the ethanol extract of Ulmus parvifolia were 32.90% and 27.70%, respectively, in SOD assay. The antioxidant activity of the water extract of Ulmus parvifolia and of the ethanol extract of Glycyrrhiza uralensis Fischer was 2.15 and 2.17, respectively, in TBARS assay. In disc method, Scutellaria baicalensis showed the highest anti-microbial activity against H. pylori, followed by Glycyrrhiza uralensis Fischer among the water extracts and Glycyrrhiza uralensis Fischer showed the highest anti-microbial activity followed by Radix puerariae among ethanol extract.