• KSBB Journal
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• 제13권2호
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• pp.214-219
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• 1998

Polymerase chain reaction(PCR) was conducted to obtain the gene encoding glucose oxidase(GOD) from Aspergillus niger(ATCC 2110) and the DNA sequence determined was coincided with published GOD sequence from A. niger. Recombinant transforming vector containing GOD and hygromycin B(hyg.B) resistant gene(hph) was constructed and used for further transformation of A. niger ATCC 2110. Selectivity of hyg.B against A. niger differed depending on which media were used i.e., nutrient-rich media such as potato dextrose agar(PDA) and complete medium(CM) showed only 50% growth inhibition at 400 $\mu$m ml$^-1$ of hyg.B while the minimal media inhibited mycelial growth completely at 200 $\mu$m ml$^-1$ of hyg.B. Twenty to sixty putative transformants were isolated from the hyg.B-containing minimal top agar, transferred successively onto alternating selective and nonselective media for a mitotic stability of hyg.B resistance and, then, single-spored. Among the stable transformants, the transformant(GOD1-6) grown by flask culture showed the considerable increase of extracellular GOD activity, which was estimated to the degree of 50% - 100% comparing to that of wild type. Transformation of tGOD1-6 was resulted from integration of the vectors into heterologous as well as homologous regions of the A. niger genome. Southern blot analysis revealed that there were two independent integrations of vector into fungal genome and one into the GOD gene due to homologous recombination. In addition, GOD activity and sodium gluconate production when tGOD1-6 was fed-batch fermented were enhanced 11 fold and 2.25 fold, respectively, compared to that of the wild type.

• Journal of Microbiology and Biotechnology
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• 제23권6호
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• pp.856-863
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• 2013

Application of rhizospheric fungi is an effective and environmentally friendly method of improving plant growth and controlling many plant diseases. The current study was aimed to identify phytohormone-producing fungi from soil, to understand their roles in sesame plant growth, and to control Fusarium disease. Three predominant fungi (PNF1, PNF2, and PNF3) isolated from the rhizospheric soil of peanut plants were screened for their growth-promoting efficiency on sesame seedlings. Among these isolates, PNF2 significantly increased the shoot length and fresh weight of seedlings compared with controls. Analysis of the fungal culture filtrate showed a higher concentration of indole acetic acid in PNF2 than in the other isolates. PNF2 was identified as Penicillium sp. on the basis of phylogenetic analysis of ITS sequence similarity. The in vitro biocontrol activity of Penicillium sp. against Fusarium sp. was exhibited by a 49% inhibition of mycelial growth in a dual culture bioassay and by hyphal injuries as observed by scanning electron microscopy. In addition, greenhouse experiments revealed that Fusarium inhibited growth in sesame plants by damaging lipid membranes and reducing protein content. Co-cultivation with Penicillium sp. mitigated Fusarium-induced oxidative stress in sesame plants by limiting membrane lipid peroxidation, and by increasing the protein concentration, levels of antioxidants such as total polyphenols, and peroxidase and polyphenoloxidase activities. Thus, our findings suggest that Penicillium sp. is a potent plant growth-promoting fungus that has the ability to ameliorate damage caused by Fusarium infection in sesame cultivation.

• 한국균학회지
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• 제41권4호
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• pp.231-235
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• 2013

붉은자루동충하초의 이용성을 증대하기 위한 기초자료로서 확보하고자 배지종류, 배양법, 산도, 탄소원, 그리고 질소원이 균사생장에 미치는 영향을 4개 균주를 대상으로 재평가하였다. 시험한 8종의 고체배지에서의 균사생장은 배지 종류 및 배양일수에 따라 균주간에 차이가 있었다. 8종의 고체배지 중 PDA 및 MMMA(mushroom minimal medium agar)서 균사생장이 우수하였다. 반면에 8종의 액체배지 중에서는 4개 균주 모두 SDYM(Sabourand's dextrose yeast extract medium) 배지에서 모두 우수한 균사생장을 보였다. 액체배지에서의 균사생장은 pH 4.0에서 pH 9.5 사이의 범위에서 큰 차이 없이 양호한 생장을 보였다. 일부 균주는 pH 8.0에서 pH 9.5의 알카리 조건에서 생장이 양호하였다. 탄소원의 경우 xylose 이용 능력이 균주간에 차이가 크게 나타났다. 질소원 경우에 Urea 이용 능력이 있는 균주가 존재함이 새로이 확인되었다. 이런 결과는 기존에 보고되지 않은 붉은자루동충하초의 새로운 균사생육 특성을 보여준다. 결론으로서 향후 새로운 붉은자루동충하초 균주를 이용하고자 할 경우는 반듯이 사전에 적정 균사생육 조건을 검토하는 것이 필요하다고 사료된다.

• 식물병연구
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• 제13권3호
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• pp.170-176
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• 2007

인삼의 잎에서 발생한 잿빛곰팡이병의 병반으로부터 병원균인 Botrytis cinerea의 224개 균주를 단포자 분리하여 실험에 사용하였다. 분리한 B. cinerea는 한천희석법을 사용하여 procymidone, carbendazim, carbendazim과 diethofencarb 합제의 균사생장 억제 효과를 $EC_{50}$(균사생장을 50% 억제하는 농도)과 MIC(균사생장을 100% 억제하는 최소농도) 값을 조사하였다. Procymidone에 대한 MIC값을 가지고서 병원균을 분류하면 0.8과 $4.0{\mu}g/ml$ 사이에 속하는 그룹과 $20{\mu}g/ml$ 이상인 그룹으로 크게 분류할 수 있었다. 2005년에 분리한 균주들은 지역별로 procymidone에 대한 감수성의 변화가 매우 다양하게 나타났다. 실험에 사용한 procymidone의 각각의 농도에 대한 균사 생장 억제 양상을 가지고 병원균을 각각 감수성($EC_{50}$ 값이 $2.0{\mu}g/ml$ 이하), 중도저항성($EC_{50}$ 값이 2.0과 $5.0{\mu}g/ml$ 사이), 저항성($EC_{50}$ 값이 $5.0{\mu}g/ml$ 이상) 등의 3개의 그룹으로 분류할 수 있었다. 이 기준으로 분류하였을 때, procymidone에 대해서 저항성인 B. cinerea의 비율은 2005년에 19.3%가 2006년에는 27.5%로 상승하였으며, 저항성 그룹의 평균 $EC_{50}$ 값도 $10.0{\mu}g/ml$에서 $237.3{\mu}g/ml$으로 상승하였다. Procymidone과 carbendazim의 경우에 다중저항성을 보이는 균주는 90개로 전체의 40.2%이었으며, 합제와의 다중저항성을 보이는 균주는 9개 밖에 없었다.

• 생물환경조절학회지
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• 제32권2호
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• pp.165-171
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• 2023

감자 마른썩음병은 Fusarium 종에 의해 발병하는 감자 저장병 중 하나이며 저장중 수확후 손실을 일으키는 대표적인 병리장해이다. 맹아억제를 위해 허용된 chlorpropham 처리는 주로 가공용 감자의 상온저장 시 이용되고 있다. 본 연구에서는 감자 저장 중 맹아의 출현을 억제하기 위해 사용되는 chlorpropham 처리가 Fusarium에 의한 마른썩음병(Fusarium solani Appel & Wollenw) 발생의 억제 효과가 있는지 확인하기 위해 감자 '단오' 품종을 이용하여 수행되었다. 마른썩음병균의 균사 생장률을 조사하기 위해균사 생장은 F. oxysporum 균사를 치상한 chlorpropham(5.0, 50.4, 503.8, 5,038ppm)과 prochloraz(0.1, 1.0, 10.0, 100.0ppm) 약제배지를 이용하여 in vitro에서 조사하였다. 20℃에서 14일간 치상한 균사는 chlorpropham과 prochloraz 처리 시 처리 농도가 높을수록 생장이 더욱 억제되었으며, 억제율은 chlorpropham 503.8ppm과 prochloraz 10ppm 처리 시 각각98.2%와 100%를 나타냈다. 20℃ 상온과 4℃ 저온저장 중 마른썩음병 방제 효과는 F. oxysporum을 접종한 감자 괴경을 chlorpropham(5.0, 50.4, 503.8ppm)과 prochloraz(100ppm)에 침지처리하여 조사하였다. 상온 저장한 감자(20℃)의 병반 직경은 저장 70일 때에 무처리구 괴경의 13.7mm에 비해 chlorpropham 50.4ppm 처리구에서만10.7mm로 유의성이 있게 억제되었다. 저온에서는 모든 처리구에서 병반 진행은 통계적 유의차가 없이 유사하였다. 본 연구 결과에서 저장 감자의 마른썩음병을 억제하기 위해서는 수확 후 chlorpropham 50.4ppm 처리가 유용할 것으로 판단된다.

• 한국균학회지
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• 18권2호
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• pp.89-96
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• 1990

Thiabendazole이 느타리버섯 재배에서 발생하는 푸른곰광이병에 방제약제로서의 가능성을 조사한바 다음과 같은 결론을 얻었다. 1. 한천배지상에서 원제농도가 50ppm 처리구에서는 ASI 2001, 2072, 2016, 100 ppm에서는 ASI 2018, 500 ppm에서는 ASI 2070호가 균사생장이 억제되었다. 2. 볏짚의 침수시 처리된 약제의 농도 중 0.2g/1000ml 이상의 처리구에서 느타리버섯 균사생장이 억제되기 시작하였다. 3. 공시약제의 모든 처리는 푸른곰광이 병원균의 처리구와 푸른곰팡이 병원균과 느타리버섯균의 혼합처리구에서도 컬럼의 하단부에 푸른곰장이병의 발생을 발견할 수 없었다. 4. 살균 전 균상표면에 약제를 농도별로 표면살포한 결과 방제효과는 $2g/m^2$ 과 $5g/m^2$의 처리구에서 병해가 발생하지 않았으며, 수량성은 $5g/m^2$ 처리구에서 가장 수량이 높았다.

• The Plant Pathology Journal
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• 제33권6호
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• pp.589-596
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• 2017

Chemical management of dollar spot in turf may lead to the development of Sclerotinia homoeocarpa populations with reduced fungicide sensitivity. The objective of this study was to investigate resistance of S. homoeocarpa isolates to triazole fungicides and to test cross-resistance among three triazole fungicides. A total of 66 isolates of S. homoeocarpa were collected from 15 golf courses across Korea, and tested via in vitro sensitivity assay against hexaconazole, propiconazole and tebuconazole. $EC_{50}$ values of the isolates to these fungicides were distributed in the range of $0.001-1.1\;a.\;i.\;{\mu}g\;ml^{-1}$. Based on the $EC_{50}$ values, twelve representative strains were selected as sensitive isolates including control and insensitive isolates with respect to each fungicide. At a concentration of $0.1\;a.\;i.\;{\mu}g\;ml^{-1}$ for all fungicides, the selected strains were distinguished as sensitive or resistant isolates with the mycelial growth inhibition rate of 50% as the criterion. The $EC_{50}$ values of resistant strains exposed to hexaconazole, propiconazole and tebuconazole were 20-50 times, 50-70 times, and 77 times greater, respectively, than that of the control strains. Two isolates of S. homoeocarpa S0-41 and Sh14-2-1 showed sensitivity toward all the fungicides used, while two other isolates Sh7-5-1 and Sh2-1-1 showed resistance to all fungicides. Each isolate showed similar resistance to the three types of triazole fungicides, whereby cross-resistance of isolates was confirmed in the present study; all three triazole fungicide combinations displayed significant correlation coefficients equivalent to or greater than 0.8.

• 아시안잔디학회지
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• 제12권3호
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• pp.183-194
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• 1998

21과 30종의 약용식물의 Rhizoctonia solani AG1-1(brown patch)와 R. solani AG2-2(large patch)에 대한 항균활성을 조사한 결과 계피, 목단피, 백선피가 강한 항균활성을 나타내었다. R. solani AG1-1에 있어 계피와 목단피는 100％ methanol로 추출한 것이 활성이 가장 높게 나왔으며 백선피는 80％ methanol로 추출한 것이 높게 나왔다. 반면에 R. solani AG2-2에 있어서는 모두 100％ methanol에서 활성이 가장 높게 나왔다. 농도별 활성은 이들 조추출물의 500배 희석액에서 60%이상 공시균주의 균사생장이 억제되었다. 항균specturum은 목단피가 가장 넓었다. 계피조추출물은 250배이상 희석액에서 목단피의 조추출물은 100배이상 희석액에서 약해를 나타내지 않았으며 백선피의 조추출물은 전혀 약해를 나타내지 않았다. 처리 30일후 방제가는 목단피 처리구 75.0％, 백선피 처리구 79.1%로였다.

• The Plant Pathology Journal
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• 제32권1호
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• pp.16-24
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• 2016

In this study, antifungal activity of essential oils of Cymbopogon citratus and Ocimum basilicum and two fungicides Mancozeb and Metalaxyl-Mancozeb in six different concentrations were investigated for controlling three species of Phytophthora, including P. capsici, P. drechsleri and P. melonis on pepper, cucumber and melon under in vitro and greenhouse conditions, respectively. Under the in vitro condition, the median effective concen- tration ($EC_{50}$) values (ppm) of plant essential oils and fungicides were measured. In greenhouse, soil infested with Phytophthora species was treated by adding 50 ml of essential oils and fungicides (100 ppm). Disease severity was determined after 28 days. Among two tested plant essential oils, C. citratus had the lowest $EC_{50}$ values for inhibition of the mycelial growth of P. capsici (31.473), P. melonis (33.097) and P. drechsleri (69.112), respectively. The mean $EC_{50}$ values for Metalaxyl-Mancozeb on these pathogens were 20.87, 20.06 and 17.70, respectively. Chemical analysis of plant essential oils by GC-MS showed that, among 42 compounds identified from C. citratus, two compounds ${\beta}$-geranial (${\alpha}$-citral) (39.16%) and z-citral (30.95%) were the most abundant. Under the greenhouse condition, Metalaxyl-Mancozeb caused the greatest reduction in disease severity, 84.2%, 86.8% and 92.1% on melon, cucumber, and pepper, respectively. The C. citratus essential oil reduced disease severity from 47.4% to 60.5% compared to the untreated control ($p{\leq}0.05$). Essential oils of O. basilicum had the lowest effects on the pathogens under in vitro and greenhouse conditions. These results show that essential oils may contribute to the development of new antifungal agents to protect the crops from Phytophthora diseases.

• 생명과학회지
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• 제11권3호
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• pp.235-241
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• 2001

To select the sntagonistic bacteria against B. cinerea, isolates were screened from the eggplant leaves and rhizosphere soils in the eggplnat fields in the greenhouse. W1 and P99 isolates were selected by the inhibition of mycelial growth of B. cinerea E12 in vitro test. These isolates, W1 and P99, were identified as Bacillus subtilis and Pseudomonas putida, respectively, by the Bergeys manual and API systems, For the formulation of the antagonistic bacteria, the media for the mass production were prepared with biji(soybean curd residues) or soybean flour. B. subtilis W1 or P. putida P99 was mass cultured in biji broth or soybean flour extrect broth and then soybean flour, corn starch flour, rice glutinous flour and biji flour as high molecular substrates were added. These mixtures were dried, grinded and formulated as brofungicides of wettable powder type. The assess the control effect of biofungicides against the infection of B. cinerea, six types of formulations were assayed at the pot culturing with eggplant in the greenhouse. According to the results, there were no significant differences among the formulation methods. However, P99S or PppB formulated with P. putida P99 showed the highest control values as 90.4% and 96.1%, respectively. Then. BSB or BSD formulated whit B. subtilis W1 were 80.8% and 83.0%, respectively. There afforementioned values were more effective than that of chemical fungicide. Ipro W.P which showed as 72.6%.