• Korean Journal of Microbiology
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• v.46 no.1
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• pp.73-79
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• 2010

The Korea Polar Research Institute (KOPRI) has assembled a culture collection of cold-adapted bacterial strains from both the Arctic and Antarctic. To identify excellent protease-producers among the proteolytic bacterial collection (874 strains), 78 strains were selected in advance according to their relative activities and were subsequently re-examined for their extracellular protease activity on $0.1{\times}$ ZoBell plates supplemented with 1% skim milk at various temperatures. This rapid and direct screening method permitted the selection of a small group of 15 cold-adapted bacterial strains, belonging to either the genus Pseudoalteromonas (13 strains) or Flavobacterium (2 strains), that showed proteolytic activities at temperatures ranging between $5-15^{\circ}C$. The cold-active proteases from these strains were classified into four categories (serine protease, aspartic protease, cysteine protease, and metalloprotease) according to the extent of enzymatic inhibition by a class-specific protease inhibitor. Since highly active and/or cold-adapted proteases have the potential for industrial or commercial enzyme development, the protease-producing bacteria selected in this work will be studied as a valuable natural source of new proteases. Our results also highlight the relevance of the Antarctic for the isolation of protease-producing bacteria active at low temperatures.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1996.04a
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• pp.233-233
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• 1996

배지의 영향에 대하여 검토하기 위하여 SDA, MHA, NA 및 BHIA를 사용하였으며, 시험균주 중 Pseudomonas aeruginosa에 대하여만 NA에서의 MIC 값이 낮게 나타났을 뿐 나머지 균주에 대하여는 배지에 따른 항균력 변화가 관찰되지 않았으며, 배지의 pH를 5.4-8.4까지 변화시켰을 때 pH 변화에 따른 DA-1131의 유의적인 항균력 변화와 접종균량에 따른 항균력 변화가 관찰되지 않았다. Methicillin-resistant Staphylococcus aureus(MRSA)에 대하여는 DA-1131과 vancomycin 간의 상승 및 상가작용이 관찰되었고, P. aeruginosa, Klebsiella pneumoniae, Enterobacter cloacae 및 Serratia marcescens 등의 균종에 대하여는 ciprofloxacin의 상가작용이 확인되었다. Sisomicin은 P. aeruginosa에 대한 상승 및 상가작용이 인정되었으나 ceftazidime은 DA-1131에 의한 길항작용이 관찰되었다.

• Korean Journal Plant Pathology
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• v.3 no.2
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• pp.137-138
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• 1987

1985년에서 1986년, 전남지방과 제주지방에서 채집한 바나나의 이병엽과 이병과에서 Fusarium moniliforme Sheld. 가 빈번하게 분리되었다. 분리된 F. moniliforme의 대형분생포자는 대부분 3개 내지 5개의 격막이 있고, 크기는 $20.0-50.0\times2.0-3.5{\mu}m$였으며, 소형분생포자의 크기는 $5.0-12.0\times1.5-2.5{\mu}m$였다. 병원성검정 결과, 이 균의 분리균주 중에는 병원성인 계통과 비병원성인 계통이 있음을 발견하였다. 접종시험에 의해 병원성인 계통의 균주들은 바나나의 잎에 잎끝마름병을 일으켰으며, 열매에는 열매끝썩음병과 수관썩음병을 일으켰다.

• The Korean Journal of Food And Nutrition
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• v.14 no.3
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• pp.211-216
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• 2001

성인 남녀의 분변과 시판 요구르트로부터 분리한 10주의 균주들을 밤용액에 접종 발효하고 산생성과 생균수 면에서 각각 우수한 Lactobacilus sp. PAP1 과 MGG2를 분리하였다. 발효액의 저장 중 균수는 발효액의 산도에 의존하였고 산도를 낮추었을 때 생균수는 증가하였다. 이들을 혼합 배양하였을 때 발효제품의 산도와 생균수는 각각의 단독배양액에 비하여 더 컸으며 3주간 저장후 생균수도 100배 이상 컸다. 밤 용액의 발효에서 이들을 상업용 수입 종균제품과 비교하였을 때 24시간 배양엣 생균수가 더 많았다.

• Research in Plant Disease
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• v.22 no.2
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• pp.72-80
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• 2016

Gummy stem blight, caused by the fungus Didymella bryoniae, is major disease of watermelons worldwide. The objective of the present study was to establish an efficient screening system to identify watermelon resistant to D. bryoniae. An GSB3 isolate was prepared from a watermelon plant showing typical symptoms of gummy stem blight in Haman-gun and identified as D. bryoniae based on molecular analysis of internal transcribed spacer sequence. A simple mass-production technique of inoculum was developed based on spore production of D. bryoniae GSB3 under several incubation conditions and their virulence on watermelon plants. Resistance degrees of 22 commercial watermelon cultivars to the GSB3 isolate were evaluated. Among them, four watermelon cultivars showing different degree of resistance response were selected for further study. Development of disease on the cultivars according to various conditions including inoculum concentrations, incubation periods in dew chamber, and incubation temperatures was investigated. From the results, we suggest an efficient screening method for resistant watermelon cultivars to gummy stem blight. Seeds of watermelon cultivar are sown and grown in a greenhouse until plant stage of 2-fully expanded leaves. Seedlings are inoculated with D. bryoniae by spraying spore suspension of the fungus at a concentration of $5.0{\times}10^5spores/ml$. The infected plants are incubated in humidity chamber at $25^{\circ}C$ for 48 hours and then transferred to a growth chamber at $25^{\circ}C$ and 80% relative humidity with 12-hour light a day. Three to four days after inoculation, disease severity of the plant are measured using percentage of infected leaf area.

• Research in Plant Disease
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• v.10 no.4
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• pp.217-226
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• 2004

One hundred isolates of Magnaporthe grisea from Korea and China were characterized for pathogenicity using eight Korean differential varieties(KDV), six Chinese differential varieties(CDV) and six near isogenic lines(NILs) developed in China. The restriction length polymorphism of M. grisea isolates from each country also was analyzed using MGR586 as a probe. One hundred Korean isolates classified into 17 races on KDV were grouped into 29 pathotypes on Chinese near isogenic lines(NILs). Virulence of 46% of Korean isolates against all the six Chinese NILs indicated that the current six Chinese NILs alone was not enough to be used as differential varieties in Korea. Especially, susceptibility of the BL1 carrying resistance gene Pi-b to 70% of tested Korean isolates suggested that BL1(Pi-b) may not be a useful resistance source to Korean blast. Based on the virulence assays of M. grisea populations from each country were divided into two groups. About 50% of Chinese isolates showed similarity to the 30% of the Korean isolates. Especially, the isolates from northern part of China, where Japonica rice cultivars were grown, showed high similarity to the Korean isolates, while isolates from southern part of China, where Indica rice were mainly grown, showed low similarity to Korean isolates. The genome RFLPs of Korean isolates were quite different from those of southern part of China using MGR586 as a probe. These data indicated that the physiological and genetical characteristics of M. grisea population might be determined by strong interaction with cultivated rice.

• Korean Journal of Breeding Science
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• v.40 no.4
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• pp.394-400
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• 2008

Blast resistance of one hundred and thirty-one rice cultivars bred in Korea was tested with thirty Korean isolates and twenty-two Philippines isolates using three screening methods. In the blast nursery conducted in Korea and in the Philippines, average disease index of rice cultivars were 4.6 and 2.2, respectively. Seventy-nine cultivars showed different resistance reaction in Korea and in the Philippines, and 19 cultivars showed the same resistant reaction in two locations. In the seedling test, Korean blast isolates displayed different levels of virulence. 93-093, a Korean isolate, was compatible with 90 cultivars whereas 97-057 showed a compatible reaction with 13 cultivars. Twenty-three cultivars showed high level of resistance against Korean and Philippines isolates but Chucheongbyeo, Heugnambyeo, and Manmibyeo showed susceptible reaction to all blast isolates. Through the sequential planting test in Korea and in the Philippines, Palgongbyeo and Seomjinbyeo displayed durable resistance, and Nagdongbyeo and Gihobyeo showed high level of disease infection over the planting time. These results indicate that blast isolates collected in two countries have different genetic background and number of compatible isolates should be considered in definition the durability of rice cultivar to rice blast.

• Research in Plant Disease
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• v.10 no.2
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• pp.130-134
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• 2004

The pathogenesity of 25 isolates of Colletotrichum gloeosporioides from apple, 42 isolates from pepper, 5 isolates from jujube, 8 isolates from persimmon was evaluated to know transmission to strawberry from other infected plants. Followings are the results. Colony morphology and spore size on potato dextrose agar was similar. When each isolate was inoculated on leaf and petiole of strawberry, isolates from persimmon was the most pathogenic. Five isolates, one pathogenic isolate per each host, were evaluated in simulated field condition under natural rainfall for their natural infectivity. All isolates infected strawberry in field condition, so C. gloeosporioides from other hosts are potential inoculum source of strawberry anthracnose.

• Journal of Environmental Health Sciences
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• v.22 no.3
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• pp.1-7
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• 1996

Polychlorinated Biphenyls(PCBs)의 생물학적 처리가 시도되고 있으며, PCBs를 분해할 수 있는 미생물을 이용할 수 있다. 따라서 본 연구에서는 폐기된 절연유의 생물학적 처리를 위하여 PCBs를 분해하는 균을 분해하였으며, 분해된 균을 이용하여 절연유 내의 Polychlorinated Biphenyls(PCBs) 분해를 회분식 실험에서 연구하였다. 대구의 신천으로부터 유일한 탄소원으로 Biphenyl을 포함하고 있는 고체배지에서 PCBs를 분해할 수 있는 Pseudomonas sp. P2 균주를 분해하였다. PCBs의 용해도를 높이기 위해 사용된 유화제 alkyl aryl ethoxylated phosphate가 200 mg/L에서는 Pseudomonas sp. P2 균주의 성장에 영향을 미치지 않았다. 1000 mg/L의 Biphenyl과 PCBs에 Pseudomonas sp. P2를 접종하여 160시간 배양후에 Biphenyl과 PCBs의 분해가 각각 97.5%, 58.0%였다. Biphenyl 1000 mg/L에서 최대성장율($\mu_{max}$)은 0.34 $day^{-1}$, 0.26 였다. 따라서 염소가 결합되지 않은 Biphenyl는 염소가 결합된 PCBs보다 분해가 빠르게 진행되었다. 또한 Pseudomonas sp. P2는 Biphenyl과 PCBs의 분해로 부터 유도된 황색의 분해대사산물을 확인하였다. 본 연구에서는 Pseudomonas sp. P2 균주가 절연유 내의 PCBs를 분해할 수 있다는 것을 확인하였다.

• Proceedings of the Korean Society for Applied Microbiology Conference
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• 1979.10a
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• pp.248.2-248
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• 1979

식초산 발효 실험을 통하여 다음과 같은 결과를 얻었다. 1. 자연에서 초산균 52균주를 분리하고 그중 식초산 농도 5.5% 이상되는 초산균 CAU-4, CAU-15, CAU-17, CAU-46, 4균주를 선별하였다. 2. 정치배양과 진탕배양을 실시한 결과 산생성랑은 진탕배양에서 월등한 효과를 보였다. 3. 유기태 질소원의 첨가시 peptone을 0.4%까지 증가를 보였고, yeast extract는 0.1~0.2%가 최적량이고 그 이상은 산량이 감소되었다. 4. $NH_4NO_3의$ 자화성을 조사한 결과 CAU-17만이 자화하지 못하였고, 무기태 질소원으로서는 $(NH_2)_2CO가$ 가장 좋았다. 5. 무기염류는 $KH/_2PO_4,$ $MgSO_4.7H_2$ O 0~0.1% 첨가하여 약간의 효과를 보았다. 6. Glucose의 첨가량별 산량의 증가는 0.25% 첨가시 0% 첨가시 보다 증가를 보인 반면 1% 첨가시는 오히려 감소하였다. 7. 초발 alcohol농도가 낮을수록 유도기와 대수기가 단축되며 10%이상에서는 4균주 모두 산을 생성하지 못하였다. 8. 초발산도가 높을 경우 유도기가 길어지고 산생성량이 줄어 들었다. 9. 초산균의 배양온도는 $30^{\circ}C,$ $35^{\circ}C에서$ 산생성 속도가 가장 빨랐다. 10. 발효시 산생성량에 따른 세균수의 증가는 접종후 2~3일 사이에 가장 많았다. 11. 초산의 증가와 더불어 균체량은 증가하였고 pH는 약간색 감소하나 PH는 2.5이하로는 내려가지 않았다. 12. alcohol 잔량은 발효 개시 후 5 ~6일의 정지기에 가장 낮았다.