• Korean journal of applied entomology
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• v.19 no.3 s.44
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• pp.169-174
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• 1980

Regardless of the kind of the apple orchards whether received various fungicides application or not Rovral exhibited the most efficient inhibitory effect on the sporulation of Alternaria mali with the spotted leaf disks at the recommended dose $0.5{\mu}g/ml$ as well as the lower or the higher doses. When applied at the recommended doses $0.7{\mu}g,\;0.75{\mu}g,\;and\;0.7{\mu}g/ml$ of Antracol, Dithane M-45, and Dikar, respectively, these fungicides showed complete inhibitory effects on the sporulation. At the lower levels of application, they allowed the sporulation of 10,000 to 25,000 conidia/ml. Polyoxin and Difolatan, when applied on the leaf disks from the orchard that had received the fungicides application, exhibited low effects allowing the sporulation of around 20,000 conidia/ml. On the leaf disks from the orchard that had received no fungicide application, however, both fungicides showed relatively high inhibitory effects of the sporulation. The inhibitory effects of Captan, Dakonil, and Spat on the sporulation were lower than those of the aforementioned fungicides. Bayleton was the least effective among the fungicides used in the present investigation. Benlate showed promoting effect on the sporulation of the apple leaf spot fungus rather tan inhibiting.

• Research in Plant Disease
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• v.15 no.2
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• pp.130-133
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• 2009

We have conducted in vitro experiments with nano-silver liquid for their effect against various plant pathogenic bacteria. Different types of nano-silver liquid WA-CV-WA13B, WA-AT-WB13R and WA-PR-WB13R were used. These are classified based on different manufacturing processes. The tested bacteria were provided by KACC. We experimented ten bacterial isolates in Clavibacter, Erwinia, Pseudomonas, Ralstonia, and Xanthomonas genera. In order to determine the level of concentrations of control effects, different concentrations (10, 25, 50, and 100 ppm) of each different nano-silver liquid were added in the culture media. As a result, WA-CV-WA13B showed high inhibition effect against C-1 at 10 ppm, and showed minor inhibition effects against P-6, X-1, and X-2. WA-AT-WB13R showed bactericidal effect against P-6 at 10 ppm. At 10 ppm, WA-AT-WB13R showed relatively high inhibition effects against C-1, X-1, and X-2. WA-PR-WB13R showed bactericidal effects against P-5, P-6 and X-2 at 10 ppm or higher concentrations. All the tested three nano-silver liquid showed bactericidal effects against all the tested plant pathogenic bacteria at concentrations of 25 ppm or higher. These results indicated the possible use of nano-silver liquid for the control of plant pathogenic bacteria.

• Journal of agriculture & life science
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• v.53 no.3
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• pp.27-39
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• 2019

The purpose of this study was to investigate the effect of hot water treatment and pH corrected lime sulfur combination treatment on the fungicidal and bacterial disinfection effects and germination rate of organic lettuce seeds. Among the followers, Alternaria sp. was infected 53.3% and Aspergillus sp. and Cladosporium sp. Infected 14.5% and 5.4%, respectively. Bacteria were isolated only Pseudomonas sp., and infected with 16.5%. In order to investigate the effect of disinfection on the temperature of hot water (45℃, 50℃, 55℃ and 60℃). The seed germination rate sharply decreased with increasing temperature and treatment time. The germination effect and germination rate of the follower were highest when hot water treatment was carried out for 20 minutes in hot water at 50℃. In the case of combined treatment of 50℃ hot water for 10 min and 0.4% pH adjusted lime sulfur mixture, showed the highest sterilization effect and germination rate with 100% and 97.6%, respectively. The results of this study can contribute to the development of technology to sterilize not only seed surface but also fungi and bacteria inside of seed.

• Research in Plant Disease
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• v.28 no.3
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• pp.122-131
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• 2022

Colletotrichum acutatum s. lat. 20JDS8 sensitive and 20CDJ6 resistant to pylaclostrobin were used to investigate the cross-resistance with fungicides belonging to the strobilurins and the characteristics of fungicidal controlling activities with different mechanisms against the isolate resistant to the fungicide. The resistant isolate of 20CDJ6 also showed the resistance to azoxystrobin, trifloxystrobin, and kresoxim-methyl, suggesting that there is a cross-resistance relationship. All fungicides with different action mechanisms inhibited mycelial growth of both susceptible and resistant isolates of C. acutatum s. lat., but their disease control effects in fruits were different according to the fungicides. The disease control effect of isopyrazam against 20JDS8 and 20CDJ6 was very low, and fluazinam showed a control effect of 91.9% and 88.1% against 20JDS8 and 20CDJ6 only when it was treated before inoculation by spraying spore suspensions on pepper fruits without wounds. Tebuconazole and prochloraz effectively inhibited not only the mycelial growth of 20JDS8 and 20CDJ6 on potato dextrose agar medium, but also disease incidence in red pepper fruits. As a result of this study, C. acutatum s. lat. 20CDJ6 resistant to pyraclostrobin showed cross-resistance with other strobilurin fungicides. In addition, we think that fluazinam, tebuconazole, and prochloraz can be recommended as alternative fungicides for the control of red-pepper pyranthracnose pathogens resistant pyraclostrobin. However, fluazinam can be effective only if it is treated protectively before the occurrence of the disease.

• Korean Journal of Food Science and Technology
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• v.18 no.4
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• pp.283-287
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• 1986

E.O. and gamma irradiation treatment on the sterilization of ground samples of 5 different types of spices(red and black pepper, onion, garlic and ginger) were investigated. Populations of mesophilic bacteria, mesophilic spores, acid tolerant bacteria and fungi in various samples were $10^4-10^6/g,\;10^3-10^5/g,\;10^3-10^5/g\;and\;10^3-10^4/g$, respectively. Coliforms and osmophilic molds were found only in red and black pepper as $10^3-10^4/g$. A radiation dose of 5 to 7 kGy proved sufficient to redure the viable cell count of the total bacteria and fungi to the level of $10^3/g$ and they were sterilized completely by radiation dose of 10 kGy or more. Coliforms, mesophilic spores and acid tolerant bacteria were sterilized at 5,7 and 10 kGy, respectively. In the mean time $D_{10}$ values of each spices ranged from 1.38 to 2.88 kGy. Comparison of E.O. and gamma irradiation treatment showed that E.O. treatment was less effective than radiation in controlling microbial contamination in spices.

• Proceedings of the Korean Vacuum Society Conference
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• 2016.02a
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• pp.192.1-192.1
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• 2016

최근 들어, 열악한 실내 공기 환경과 미세 먼지의 유입으로 아토피 피부염, 알레르기성 비염 및 천식 등의 감염성 질환이 증가하고 있다. 따라서, 공기 중 병원균(Airborne pathogens)을 친환경적으로 제거하는 기술이 요구되고 있는 추세이다. 본 연구에서 제안하는 시스템은 물을 이용하여 플라즈마를 발생시키는 시스템이다. 기존 플라즈마를 이용한 공기 정화 장치는 공기를 사용하여 플라즈마를 발생시키므로 오존과 같은 인체에 유해한 물질들이 발생되는 문제점이 있다. 하지만, 본 연구에서는 물을 사용하여 플라즈마를 발생시키므로 활성 라디칼들이 포함된 물을 미스트 형태로 분사하여 인체에 무해하며, 대기 중 병원균 살균이 가능한 장점이 있다. 물 플라즈마 젯 분사장치는 전원 공급 장치, 플라즈마 전극 그리고 플라즈마 노즐로 이루어져 있으며 주입되는 물을 기반으로 플라즈마를 발생시킨다. 장치의 특성을 분석하기 위하여, 오실로스코프로 전압 및 전류를 측정하였고 적정법을 이용하여 생성되는 활성 라디칼들의 농도를 측정하였다. 또한 살균 능력을 평가하기 위하여 병원균 중 대표적으로 대장균을 배양하여 살균 실험을 수행하였으며, 결과적으로 90% 이상의 대장균이 사멸하는 것을 확인하였다.

• Proceedings of the Korean Society of Marine Engineers Conference
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• 2011.06a
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• pp.189-189
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• 2011

본 논문에서는 에너지 절감형 선박평형수 처리시스템 개발을 위하여, 저압 자외선 램프의 살균효율의 증대를 위한 광촉매 처리방법에 대하여 기술하였다. $TiO_2$ 광촉매를 석영관 주위에 감싸는 방법으로 살균챔버 내부에 설치하고 253.7 nm파장의 자외선과 광촉매에 의한 해수내 미생물 살균효과를 분석하였다.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.41 no.8
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• pp.113-117
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• 2004

In this paper, we present a new microwave applicator to sterilize a liquid material by using the electromagnetic energy. Also, we conducted an experiment on streamlet water with our proposed sterilizer and investigated the chosen samples according to the inspection agency The result exhibited that the total number of colitis germ and general bacillus in sterilized water has been decreased rapidly as the operating time to illuminate the microwave power risen from 10 to 60 seconds.

• Journal of Aquaculture
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• v.16 no.2
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• pp.118-123
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• 2003

This study was conducted to investigate the disinfection effects of chlorine dioxide ($ClO_2$) on 4 fish pathogenic bacteria (Vibrio anguillarum, Edwardsiella tarda, Streptococcus sp. and Staphylococcus sp.) isolated from infected olive flounders. The bacteria were exposed to different concentrations of ClO$_2$ (0.129, 0.246 and 0.455 ppm) and response times (0.5, 1, 3, 5 and 10 min), and then were incubated for 12 hr. The effective disinfection concentrations of $ClO_2$ against experimental bacteria by $ClO_2$ for 0.5 min were observed with 0.455 ppm for Staphylococcus sp., 0.246 ppm for V. anguillarum and E. tarda, and 0.129 ppm for Streptococcus sp., respectively. The duration of exposure at low concentration of $ClO_2$ increased for the disinfectant ability to experimental bacteria.

• Microbiology and Biotechnology Letters
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• v.11 no.3
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• pp.155-161
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• 1983

The effects of ultraviolet light on bacteriophage f2 were investigated to determine the inactivation kinetics and its mechanism. The 260nm light showed a little higher inactivation rate than the one of 300 nm. In this work, our main concern was whether structural and/or conformational changes in the protein capsid could occur by UV irradiation. The inactivation for the first 20 minutes irradiation was rapid with a loss of about 4 logs and followed by a slower rate during the next 40 minutes with no survival noted in the samples irradiated for 90 minutes or longer. The structural change of the protein capsid was examined by optical spectroscopic techniques and electron microscopy. The absorption spectra of the UV irradiated phages showed no detectable differences in terms of the spectral shape and intensity from the control phage. However, the fluorescence emission spectroscopic data, i.e. 1) fluorescence quenching of tryptophan residues upon irradiation of 300 nm light, 2) enhancement of fluorescence emission of ANS (8-aniline-1-naphthalene sulfonate) bound to the intact phages compared to the one in the UV-treated phages, and 3) decrease of energy transfer efficiency from tryptophan to ANS in the UV-treated samples, presented remarkable differences between the intact and UV-treated phages. Such a structural alteration was also observed by electron microscopy The UV-treated phages appeared to be broken and empty capsids. Therefore, the inactivation of the bacteriophage f2 by UV irradiation is thought to be attributed to the structural change in the protein capsid as well as damage in the viral RNA by UV irradiation.