• 농업과학연구
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• 제15권1호
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• pp.23-26
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• 1988

1987년(年) 대전(大田) 근교(近郊)의 vinyl house에서 재배중(栽培中)인 백합(百合)(Lilium spp.)에서 Botryis elliptica에 의한 잎마름병(病)이 국내(國內)에서 최초(最初)로 발견(發見)되었다. 본(本) 병(病)의 초기(初期) 병징(病徵)은 잎과 줄기에 나타나는 갈색(褐色) 점(點)무늬로서 점차 확대(擴大)되어 잎마름 증상(症狀)을 나타내었고 발병(發病)이 심(甚)하면 식물체(植物體) 전체(全體)가 갈변(褐變)하고 고사(枯死)되었다. 병원성(病原性) 검정(檢定) 결과(結果) 본(本) 병원균(病原菌)은 백합(百合)에만 병원성(病原性)이 있었고 고추, 토마토, 인삼, 양파, 파에는 병원성(病原性)이 없었다. 본(本) 병(病)은 국내(國內) 미기록병(未紀錄病)으로 Botrytis elliptica(Berk.) Cooke에 의(依)한 백합(百合) 잎마름병(病)(엽고병(葉枯病))으로 명명(命名)하고자 한다.

• 식물병연구
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• 제9권3호
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• pp.149-152
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• 2003

전남 광양읍 봉강면의 양란 재배농가에서 재배되고 있는 덴파레에 검은점무늬병이 발생하였다. 자연 발병한 덴파레의 잎에는 초기에 검은색의 작은 점무늬가 형성되어 점차 진전되면서 잎 전체가 누렇게 변하면서 고사해 버리며 소엽병의 마디가 약화되어 낙엽이 지고 심하면 식물체 전체가 말라죽었다. 검은점무늬병에 감염된 덴파레의 병환부로부터 분리된 병원균은 감자한천배지 상에서 초기에 흰색을 띠며, 점차 시간이 지남에 따라 진한 보라색을 띠었으며, 균사생장 적온은 $25^{\circ}C$였다. 덴파레 잎의 검은 점무늬 병반으로부터 분리한 병원균은 균학적 특성 및 병원성 검정 결과 Fusarium moniliforme로 동정되었다. 병원균은 상처 접종에 의해서만 덴파레에 병원성을 나타내었고, 호접란과 심비디움에 대해서도 모두 병원성을 나타내었다. 따라서 이 병을 Fusarium moniliforme에 의한 덴파레 검은점무늬병으로 명명할 것을 제안한다.

• The Plant Pathology Journal
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• 제22권1호
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• pp.7-10
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• 2006

Anthracnose severely occurred on begonia (Begonia semperflorens Link.) nurseries in Gyeongju, Gyeongbuk in July, 2004. More than $80\%$ of begonia seedlings were diseased in the greenhouse surveyed and diseased leaves per plant were $12.1\%$ in average. Yellowish spots occurred on the leaves of begonia as initial symptoms, and they coalesced irregularly to form large brown pleomorphic lesions. Severely infected leaves were defoliated, resulting in abnormal growth of the entire plant. Colletotrichum sp. was repeatedly isolated from the diseased plants and was identified as Colletotrichum acutatum on the basis of the mycological characteristics on potato dextrose agar and RAPD analysis. Pathogenicity of the fungus was also confirmed by artificial inoculation on healthy plants. The optimum temperature for mycelial growth of C. acutatum was around $25^{\circ}C$. The fungus was sensitive to azoxystrobin, bitertanol, diethofencarb-carbendazim, difenoconazole and tebuconazole. This is the first report on the anthracnose of begonia caused by C. acutatum in Korea.

• The Plant Pathology Journal
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• 제26권2호
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• pp.154-158
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• 2010

Early nematode development and subcellular responses in resistant soybean lines PI 88788 and PI 437654 infected with races 3 (R3) and 14 (R14) of soybean cyst nematode (SCN), Heterodera glycines Ichinohe, were compared. SCN R14 nematodes penetrated and developed significantly more than R3 at 5-6 days after inoculation. Both races also penetrated and developed more in PI 88788 than in PI 437654. Syncytia, characterized by cell wall dissolution and cellular hypertrophy, were developed more in PI 88788 than in PI 437654 and more by R14 than R3, for which less necrotic responses occurred in the former than the latter. This suggests that the latter two may be more resistant and less virulent than the former two, respectively. A common structural feature found in each of PI 437654 and PI 88788 in relation to SCN-resistance was the formation of prominent cell wall appositions and nuclear degeneration prior to cytoplasmic degradation in syncytial cells, respectively. Necrosis and cell wall apposition are types of hypersensitive responses occurring at early stages of the nematode infection so that these structural modifications indicate the inhibition of initial syncytial development related to the early nematode development. As soybean cultivars and lines with identical or similar genotypes have the same types of structural features related to SCN-resistance, the structural modifications induced by SCN infection may result from the expression of inheritable resistance genes, of which the information can be used for breeding soybean cultivars and lines specifically resistant to SCN races.

• 한국미생물·생명공학회지
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• 제30권3호
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• pp.253-257
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• 2002

쌀대신에 보리를 이용한 Monascus 고상배양의 기본적인 발효 특성을 연구함을 통하여, 대규모 고상배양 시스템을 통한 천연 적색색소의 생산 가능성을 검토하고자 하였다. 색소의 생산은 고상배양 3일후부터 6일까지 꾸준한 증가추세를 나타내었다. 종균의 접종량이 6∼8%사이일 경우에는 배양후 60시간만에 색소생산이 시작되었으며, 접종량이 5%이하일 경우에는 색소생산이 70시간 이후로 늦어지는 것으로 나타났다. 보리 배지를 30∼40분 동안 증자할 경우에는 색소 발현 시점이 45시간 내외로 단축되었으며, 증자시간이 20분 이하일 경우에는 배지의 불충분한 호화로 인하여 색소생산 시점이 길어졌다. 공기공급량이 0.6∼0.8 vvm사이에서 홍국균의 생장 및 색소의 생산이 활발히 일어났고, 고상배지의 초기 pH를 6으로 조절했을 때 균사성장과 색소발현 능력이 가장 우수하였다 한편 고상배양으로 7일동안 발효한 홍국보리를 사용하여 식중독미생물에 대한 항균여부를 확인한 결과, Escherichia coli, Salmonella 수Phimurium의 생장을 저해함을 확인하였다. 이상과 같이, 보리를 원료로 한 대규모 고상발효 시스템을 활용함으로써 Monascus sp. 유래의 천연색소 및 대사산물의 대량생산 가능성을 확인하였다.

• Biotechnology and Bioprocess Engineering:BBE
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• 제11권5호
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• pp.408-413
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• 2006

We assessed the ability of a Pseudonocardia sp. from soil samples to bioconvert vitamin $D_3$. The optimal culture conditions for the bioconversion of vitamin $D_3$ to active $1{\alpha}$,25-dihydroxyvitamin $D_3$ were investigated by varying the carbon and nitrogen sources, the metal salt concentrations, the initial pH, and the temperature. Microbial transformations were carried out with the addition of vitamin $D_3$ dissolved in ethanol. They were sampled by extraction with methanol-dichloromethane and the samples were examined by HPLC. Optimum culture conditions were found to be 0.4% yeast extract, 1% glucose, 3% starch, 1% fish meal, 0.2% NaCl, 0.01% $K_2HPO_4$, 0.2% $CaCO_3$, 0.01% NaF, and pH 7.0 at $28^{\circ}C$. The optimal timing of the addition of vitamin $D_3$ for the production of calcitriol by Pseudonocardia autotrophica ID9302 was concurrent with the inoculation of seed culture broth. Maximum calcitriol productivity and the yield of bioconversion reached a value of 10.4mg/L and 10.4% respectively on the 7th day in a 75L fementer jar under the above conditions.

• The Plant Pathology Journal
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• 제29권1호
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• pp.42-51
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• 2013

One of the most important limiting factors for the production of the grafted cactus in Korea is the qualitative and quantitative yield loss derived from stem rots especially caused by Bipolaris cactivora. This study is aimed to develop microbial control agents useful for the control of the bipolaris stem rot. Two bacteria (GA1-23 and GA4-4) selected out of 943 microbial isolates because of their strong antibiotic activity against B. cactivora were identified as Bacillus subtilis and B. amyloliquefaciens, respectively, by the cultural characteristics, Biolog program and 16S rRNA sequencing analyses. Both bacterial isolates significantly inhibited the conidial germination and mycelial growth of the pathogen with no significant difference between the two, of which the inhibitory efficacies varied depending on the cultural conditions such as temperature, nutritional compositions and concentrations. Light and electron microscopy of the pathogen treated with the bacterial isolates showed the inhibition of spore germination with initial malformation of germ tubes and later formation of circle-like vesicles with no hyphal growth and hyphal disruption sometimes accompanied by hyphal swellings and shrinkages adjacent to the bacteria, suggesting their antibiotic mode of antagonistic activity. Control efficacy of B. subtilis GA1-23 and B. amyloliquefaciens GA4-4 on the cactus stem rot were not as high as but comparable to that of fungicide difenoconazole when they were treated simultaneously at the time of pathogen inoculation. All of these results suggest the two bacterial isolates have a good potential to be developed as biocontrol agents for the bipolaris stem rot of the grafted cactus.

• 한국작물학회지
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• 제34권1호
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• pp.14-22
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• 1989

벼 잎집무늬마름병에 대하여 저항성반응이 다른 품종을 시험하여 병균접종구, 자연구 및 약제방제구를 두어 병 발생에 의한 수량감소률의 품종간 차이를 2년간에 걸쳐 조사한 결과를 요약하면 다음과 같다. 1. 시험한 품종 중에서 가야벼는 병균접종구나 자연구에서의 발병정도가 가장 낮았으며 태백벼, 관악벼 및 Labelle은 균발생이 심하였고, 약제방제구에서는 병이 거의 발생하지 않았다. 2. 중반저항성품종인 가야벼는 2년간에 걸쳐 병균접종구 및 자연구에서의 수량감소률이 0.3∼5％로 공시품종 중에서 가장 낮았으며 이병성품종인 태백벼는 6.8∼25.8％로 가장 높았고 관아벼와 Labelle도 각각 10％내외의 수량감소률을 보였다. 3. 시험품종의 저항성정도에 관계없이 동일한 품종내에서 잎집무늬마름병의 병반이 지엽까지 진전된 분얼경에서는 등숙비육과 정조천립중이 감소하여 건전경에 비하여 이삭무게가 25％이상 감소하였다. 4. 잎집무늬마름병에 대하여 상위엽으로의 병반진전이 더디게 되었기 때문에 수량감소율이 낮았다.

• Food Science and Biotechnology
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• 제18권5호
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• pp.1100-1108
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• 2009

Lactic acid bacteria (LAB) isolated from various fruits and vegetables were screened in order to determine appropriate fermentation starters for manufacturing functional fermented onion juice. From the initial screening test comprising more than 700 isolated LAB, 16 isolates were selected based on their acid production rate. Among the selected isolates, the fermentation broth of KC-007 exhibited the highest electron donating and nitrite scavenging activities, with values at pH 1.2 of 95.6 and 68.7%, respectively. From the overall results obtained in this study, we finally selected the bacterium KC-007 as a fermentation starter. This bacterium was identified and named as Pediococcus pentosaceus based on its morphological and physiological characteristics, carbon-utilization pattern (as assessed using an API 50CHL kit), and molecular genetic characteristics (as assessed using the nucleotide sequence of the 16S rRNA gene). The optimal temperature, pH, and starter inoculation concentration (v/v) required for growth of the isolated strain were $40^{\circ}C$, pH 4.0-6.0, and 2%(v/v), respectively.

• 한국식품조리과학회지
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• 제24권4호
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• pp.445-451
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• 2008

This study compared the effects of chlorine dioxide and a commercial chlorine sanitizer for inhibiting foodborne pathogens, including Salmonella enterica serovar Typhimurium, Listeria monocytogenes, and Escherichia coli O157 : H7, on lettuce leaves. The lettuce samples were inoculated with each cocktail of the three strains, and were then treated with chemical sanitizers [distilled water, 100 ppm commercial chlorine and 50 ppm, 100 ppm, 200 ppm chlorine dioxide ($ClO_2$)] for 1 min, 5 min, and 10 min at room temperature($22{\pm}2^{\circ}C$). Following inoculation of the leaves, initial populations of E. coli O157:H7, L. monocytogenes, and S. Typhimurium were approximately 5.54, 4.47, and 5.12 log CFU/g, respectively these levels were not significantly reduced by the treatment with water,whereas the 100 ppm commercial chlorine sanitizer treatment and $ClO_2$ (at all tested concentrations) were effective at reducing levels of all three pathogens. The treatment of 200 ppm $ClO_2$ for 10 min was most effective at inhibiting the three pathogens, and reduction levels of E. coli O157 : H7, L. monocytogenes, and S. Typhimurium were 2.28, 1.95, 1.76 log, respectively. The inhibitory effect of $ClO_2$ increased with increasing treatment concentration of $ClO_2$, but there was no significant difference by the treatment times. When chemically injured cells of E. coli O157 : H7 and L. monocytogenes and S. Typhimurium were examined by SPRAB and selective overlay methods, respectively, it was observed that the commercial chlorine sanitizer generated greater numbers of injured L. monocytogenes than the $ClO_2$ treatment. From the overall results, $ClO_2$ was more effective at inhibiting pathogenic bacteria compared to the commercial chlorine sanitizer therefore, it has potential to be utilized as an alternative sanitizer to increase the microbial safety of fresh produce.