• Research in Plant Disease
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• v.20 no.4
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• pp.283-288
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• 2014

Citrus canker caused by Xanthomonas citri subsp. citri (Xcc) has been quarantined by many countries in the world. Recently, the usage of methyl bromide should be limited, application by gamma irradiation on the agricultural production is raised as an alternative method. In this study, the level of gamma irradiation which could decrease of population of Xcc in the suspension or on the surface of citrus fruit was investigated. The $D_{10}$ value of Xcc, which is radiation dose required to reduce the number of the microorganism, was 55 and 28 Gy in the suspension and on the surface of citrus fruit, respectively. Furthermore, disease severity was suppressed on the citrus leaves inoculated with Xcc suspension pre-treated with gamma irradiation. Based on this study, it is suggested that Xcc on the citrus fruit could be eradicated by gamma irradiation and the results of this study may be valuable for application of gamma ray in quarantine activity.

• Journal of Life Science
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• v.24 no.10
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• pp.1110-1117
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• 2014

Tidal flats are continuously contaminated by human activities. This study assessed the bioremediation efficiency of tidal flat soil using microcosm reactors and microorganisms originating from the tidal area. We screened 135 bacterial strains that produce extracellular enzymes from the tidal area located in the North port of Incheon bay. Two bacterial strains (Pseudoalteromonas sp. and IC35 Halothiobacillus neapolitanus IC_S22) were selected and used in the microcosm reactors, which were specially designed to functionally mimic the ecological conditions of the tidal flats. Pseudoalteromonas sp. IC35 was selected based on its relatively high activity of the enzymes amylase, cellulose, lipase, and protease. Halothiobacillus neapolitanus IC_S22 was selected for oxidation of sulfur. The M1 and M2 microcosm reactors were operated by continuous feeding of seawater under the same conditions, but M2 was first inoculated with Pseudoalteromonas sp. IC35 before the seawater feeding. The initial COD in both the M1 and M2 microcosm reactors was 320 mg/l. The final COD was 21 mg/l (M1) and 7 mg/l (M2). The M3 and M4 microcosm reactors were operated by continuous feeding of seawater under the same conditions, but M4 was first inoculated with H. neapolitanus IC_S22. The initial sulfate concentration in both the M3 and M4 microcosm reactors was 660 mg/l, and the maximum sulfate concentration was 1,360 mg/l (M3) and 1,600 mg/l (M4).

• Korean Journal of Poultry Science
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• v.37 no.1
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• pp.35-41
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• 2010

The effect of combination of chitosan coating and gamma irradiation on Escherichia coli inactivation and nutritional properties of shell egg was investigated. The E. coli inoculated on shell egg was not detected by 2 kGy of gamma irradiation at day 0 and/or chitosan coating (1%, pH 5.0) after 3 days of storage. There was no E. coli detected thereafter. In the contents of moisture, crude fat, crude protein, ash, retinol, phospholipid, and minerals, no difference was found by treatment combination. However, the contents of cholesterol and carotenoids were reduced by irradiation of 2 kGy (P<0.05). Results suggest that the combination of gamma irradiation (2 kGy) and chitosan coating (1%) can be a good method to improve the safety and prolonged shelf-life of egg because of effective pathogen inactivation without significant adverse changes in nutritional quality.

• The Journal of the Korean Society for Microbiology
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• v.6 no.1
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• pp.15-20
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• 1971

A vaccine was prepared by $10^6$ r cobalt-60 irradiation of lyophilized virulent Brucella melitensis and tested in mice for immunogenic activity against a lethal challenge dose of the homologous strain. The vaccine(GIV) produced a high degree of immunity in mice, and comparative studies demonstrated it to be superior to vaccines prepared by heat or by chemical(ether, formalin, or phenol) treatment. Living vaccines, Brucella abortus. strain 19 and an R-form of Brucella melitensis were lethal for mice in larger doses. A comparison of seven adjuvant mixtures for use with the GIV showed no statistically significant difference, but. Freund's complete adjuvant and a mixture of aluminum-potassium sulfate and pectin appeared to enhance the activity of the GIV.

• Korean Journal Plant Pathology
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• v.14 no.5
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• pp.536-542
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• 1998

Ten isolates of the orchid mycorrhizal fungi were isolated from the roots of Korean native orchid plants (Cymbidium goeringii) which inhabitate mainly in southern and western areas of Korea. The growth rates and color of the isolates in potato dextrose agar (PDA) were various. Microscopic observations of the hyphae isolated were identified as Rhizoctonia repens and R. endophytica var endophytica or their related species. R. repens was isolated from the roots of the Korean native orchids, but R. endophytica var endophyica was only isolated from the roots of the commercial orchids introduced from foreign countries. Also, the polymorephic patterns of genomic DNA extracted from selected isolates were compared with those of DNA extracted from the orchid mycorrhizal fungi isolated previously and similar band patterns were observed among those isolates. Five isolates of R. repens were selected and cultured at the oatmeal agar for investigating their symbiosis with orchid plants. The symbiotic specificity between orchid plants and isolated orchid mycorrhizal fungi was observe by growing orchids about six months in the greenhouse. The symbiotic responses of the commercial orchid plants with selected isolates were quite different form different isolates due to the genetic variations.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1993.04a
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• pp.144-144
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• 1993

한국에서 유행하는 페염균 type을 결정하기 위한 기초 실험을 수행하여 서울대병원과 서울중앙병원의 환자로부터 분리한 88개의 폐염균주를 담즙산에 의한 용해도 및 Optochin에 대한 민감성 등을 측정하고 폐염균의 type을 결정하기 위해서 Double diffusion, Countercurrent immunoelectrophoresis, Rocket immunoelectrophoresis 방법 등으로 폐염균 항혈청과 반응하였다. 또한 ATCC로부터 구입한 폐염균주를 이용하여 배지조성의 변화에 따른 폐염균 생장을 측정하기 위해 CAT broth, Brain Heart Infusion broth, Defined Media에서 3가지 type의 균주(Type I, III, IV)를 접종하고 37$^{\circ}C$에서 배양하면서 1시간마다 550nm에서 흡광도를 측정하였다. 3가지 type (Type I, III, IV)의 폐염균주로부터 협막다당류를 phenol Iysis 추출법으로 폐염균 Capsule 다당류의 분리하여 Total Sugar 함량, Uronic acid 함량, 0-Acetyl 함량, 단백질 함량, 핵산 함량, 분자량분포 Countr-current immunoelectrophoresis 등을 실시하여 폐염균 백신 규격에 부합되는지 확인하였다. 수집한 88개의 폐염균주가 모두 담즙산에 의해 용해되고 6mm Optochin disc를 사용하였을때 성장 저지원이 모두 14mm 이상으로 나타나 감수성이 있어서 폐염균임을 확인하였으며 폐염균의 type 결정에 필요한 방법을 설정하였다. 배지조성에 따른 폐염균의 생장을 측정한 결과 CAT broth 에서는 Type I만이 잘 배양되었고 Type III, IV는 늦게 배양되었으나, Brain Heart Infusion broth에서는 3가지 Type이 모두 잘 배양되었고, Defined Media 에서는 Type I만이 성장되었을 뿐 나머지 두 Type은 배양되지 않았다. 본 실험방법으로 분리된 폐염균 다당류는 폐염균 백신 규격중의 6가지 항목에서 적합하였으며 Statens(Denmark)로부터 구입한 항체와 뚜렷한 침강선을 나타내었다.

• The Korean Journal of Mycology
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• v.21 no.2
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• pp.85-93
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• 1993

Eighty two soil samples were nation widely collected from nine places in Korea. Each soils were used as the inocula for the pot culture of arbuscular mycorrhizal fungi. The twenty two species of arbuscular mycorrhizal fungi were successfully cultured by using the small pots under the conditions of green house and identified under light microscopes. Out of them, the five species were first isolated and decribed in Korea; Acaulospora morrowiae, A. rugosa, A. longula, Glomus fecundisporum, Gl. deserticolar. Three species of genus Glomus were not identified and Glomus clarum reporeted by Eom and Lee (1989) was redescribed.

• Journal of Forest and Environmental Science
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• v.29 no.2
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• pp.173-180
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• 2013

Berries of Korean mistletoe (Viscum album var. coloratum [Kom.] Ohwi) contained one seed, which have, in general, one or two embryos but very rarely three embryos. Mucilaginous substances in berries may help them adhere to the branches of host trees. It was observed that seeds need more than one and half years to develop into normal and healthy seedlings from the time of inoculation. Many factors such as adhesion of berry, thickness of host branch, orientation of haustorial root, etc. influenced the successful development of mistletoe plants. Through the application of six-year observation results on the germination of seeds and growth of seedlings, about 80% of germination rate for mistletoe seeds and 61% of survival ratio for germinated seeds, which is more than 23 times higher in natural conditions, were obtained after inoculation of seeds on the one-year-old branches of Malus pumila var. dulcissima and Quercus mongolica trees. The technological aspects of the success can be applied to other host plants and provide a critical clue to an artificial propagation system, for this medicinally valuable genus. This is the first successful report on artificial inoculation and plant development of Korean mistletoe.

• Pediatric Infection and Vaccine
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• v.6 no.2
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• pp.239-244
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• 1999

Purpose : In 1998, there was an outbreak of mumps in Taejon, Korea. We analyzed the monthly incidence, clinical manifestations, and complications during the outbreak and the annual incidence of the recent ten years. Methods : We reviewed the clinical records of 35 mumps patients who had been admitted to Taejon St. Mary's Hospital from January to December, 1998. Results : Mumps was prevalent in summer(from June to August) with 20 cases(57%). Thirthy-three patients(94.3%) received MMR at 15 months of age and no patients received a booster mumps vaccine. The mean age of the mumps patients was 10.5 years-old and the majority of mumps(71%) occurred between 5 and 12 year of age. The male female ratio was 2.2 : 1. The clinical manifestations were swelling of parotid gland(100%), fever (91%), vomiting(77%), abdominal pain(74%) and headache(66%) in order of frequency. Meningitis occurred in 20 cases(57%) and the mean WBC count of CSF was $464{\pm}263/mm^3$. In serology, the mean serum amylase level was $483{\pm}294IU/dL$ and anti-mumps IgM and IgG were positive in 11 and 15 out of 18 cases, respectively. From 1989 to 1997, the mean number of inpatients with mumps was 3.4 per year. Conclusion : We experienced an outbreak of mumps in 1998. It is suggested that there was a primary mumps vaccine failure in Korea and that further studies for vaccine faiure and method of booster mumps vaccine are necessary.

• Journal of the Korean Society of Food Science and Nutrition
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• v.34 no.5
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• pp.729-733
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• 2005

This study was conducted to sanitize fried-frozen cheese ball by gamma irradiation. Total aerobic bacteria and yeasts and molds counts were 4.4 and 2.8 log CFU/g in non-irradiated sample, respectively. Microorganisms were decreased with increase of irradiation dose $(D_{10}=1.25\;kGy)$, and were not detected in samples irradiated at 3 kGy or more $(<10^2\;CFU/g)$. $D_{10}$ value for Escherichia coli (KCTC 1682) was 0.25 kGy. TBA (2-thiobarbituric acid) values were increased as irradiation dose was increased, but there was no significant difference between non-irradiated and irradiated samples at 3 kGy or less (p<0.05). The results of sensory evaluation showed that there was no significant difference between non-irradiated and irradiated samples at 3 kGy or less, the sensory scores were decreased with irradiation at 5 kGy or more (p<0.05). These results indicated that gamma irradiation at 3 kGy was considered to be an effective treatment to ensure the microbiological safety of fried-frozen cheese balls without any sensorial change, even though further studies should be investigated to reduce detrimental effects induced by irradiation.