• 한국환경농학회지
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• 제20권1호
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• pp.50-56
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• 2001

부패된 콩이나 콩나물에 존재하는 33종$(K-1{\sim}K-33)$의 각종 미생물로부터 콩나물 부패에 관여하는 세균(K-17)과 진균(K-28)을 각각 1종류씩 분리하였으며, 이들은 각각 Erwinia carotovora와 Fusarium sp.로 동정하였다. 콩나물 부패균에 길항하는 미생물은 각종 토양 균원시료로부터 분리한 350여종의 세균을 이용하여 콩나물 부패세균인 K-17 균주와 진균인 K-28 균주에 각각 길항력을 나타내는 J-232 세균을 최종 선발하였다. 길항균 J-232는 Pseudomonas fluorescens로 동정되었다. 콩나물 부패균 E. carotovora K-17과 Fusarium sp. K-28의 배양액으로 재배한 콩나물은 시루 아랫부분이 부패하였으나, 길항균 P. fluorescens J-232는 PDA 한천배지에서도 부패균들의 생육을 억제하였을 뿐만아니라 길항균 배양여액을 단독으로 콩나물재배에 처리할 경우에도 시루 내 콩나물은 부패되지 않았다. 콩나물 부패균 E. carotovora K-17과 Fusarium sp. K-28의 배양액에 길항균 P. fluorescens J-232의 배양액을 원액 또는 500배까지 희석하여 침지한 후 재배한 콩나물도 전혀 부패되지 않았으며 생육이 약간 촉진되는 경향이었다.

• 한국유기농업학회지
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• 제25권1호
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• pp.113-124
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• 2017

목화진딧물과 복숭아혹진딧물은 채소를 포함한 다양한 작물에 큰 피해를 주는 해충이다. 이들 해충의 친환경 방제를 위해 진딧물에 병원성이 높은 곰팡이(B. bassiana) 유래 대사물질을 이용한 방제 연구를 수행하였다. 이 균주의 배양여액의 살충율은 목화진딧물에 처리 3일 후 100%, 복숭아혹진딧물에 처리 5일 후 99%였다. 이 추출물을 $CHCl_3$ : MeOH 비율을 달리하여 silica gel column chromatography 한 결과, 50:1 ($CHCl_3$ : MeOH)의 추출물 분획의 살충률이 목화진딧물과 복숭아혹진딧물에 각 80%와 75.4%로 다른 분획에 비해 현저하게 높았다. 또 각 용매비율별 추출물을 1:1로 혼합하여 처리한 결과, 분획 추출물 혼합에 의한 상승효과는 보이지 않았으며 두 진딧물에 모두 50:1 ($CHCl_3$ : MeOH) 단독처리에서 살충률(목화진딧물 77.3%, 복숭아혹진딧물 76.4%)이 가장 높았으며 50:1 + 70:1이 두 번째로 높았다(목화진딧물 72%, 복숭아혹진딧물 70.2%). 앞으로 안정적인 진딧물 방제를 위해 50:1 분획 추출물 내 진딧물 살충성 물질을 분리 동정 및 대량생산 연구를 진행할 예정이다.

• Journal of Microbiology and Biotechnology
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• 제10권3호
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• pp.287-292
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• 2000

Recombinant Aspergillus niger was constructed to express and secrete a biologically active murine granulaocyte macrophage-colony stimulating factor (mGM-CSF). A 500 bp fragment encoding the signal peptide and terminator of glyceraldehyde-3-phosphate dehydrogenase (gpd). The hygromycin phosphotrasferase gene (hph) was used as a selection marker for the fungal transformants. An expression vector was introduced into A. niger ATCC 9642, and a Northern blot analysis indicated the presence of a considerable amount of transcripts from the introduced mGM-CSF. The biological activity of recombinant mGM-CSF (rmGM-CSF) isolated from the culture filtrate was confirmend by measuring the proliferationof the GM-CSF dependent FDC-P1 cell line. It appeared that rmGM-CSF was amenable to the proteolytic activity produced by A. niger, since biological actibity was only observed when the transformants were grown in a protease-repressing medium, and the activity of rmGM-CSF dramatically decreased with an increase of age of the culture. The yield of rmGM-CSF, as determined by ELISA. was 640 ng/l of culture filtrate. Accordingly, its specific activity is estimated to be approximately two-and-a-half times higher than that of a commercial preparation from E. coli.

• 한국식물병리학회지
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• 제11권4호
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• pp.292-297
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• 1995

We developed an in vitro assay method for evaluating plant growth promotion and providing an evidence that the growth promotion is rendered by growth enhancing factors. The amendment of culture filtrates of Trichoderma harzianum T95 and Gliocladium virens G872 and G872B in Murashige and Skoog (MS) agar medium enhanced the cotyledon growth of cucumber in terms of fresh weight and primary leaf area of cucumber cotyledon cuttings, of which the treatment of G. virens G872B was the most effective. The mycelial culture filtrate of G872B was more effective in the growth promotion than its conidial germling filtrate. The addition of 1% sucrose in MS mineral medium with 0.1% culture filtrates of the antagonists (T95 and G872B) was optimum for enhancing the effect of the filtrates on the growth of cotyledon cuttings in vitro. When cucumber seeds treated with G872B, Pseudomonas putida Pf3 or the G872B-Pf3 mixture were planted in a greenhouse, the rate of seed germination, biomass of shoot and root, and yield of cucumber fruits were increased, especially by G872B or the G872B-Pf3 mixture. Correspondingly, cucumber fruit yields in early to middle-cycles of harvest were significantly greater in the plots of G872B than the control and Pf3-treated plots, and the final yield was highest in the plots of the G872B-Pf3 mixture applications.

• Mycobiology
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• 제43권1호
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• pp.87-91
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• 2015

Eighteen endophytic fungi with different colony morphologies were isolated from the roots of Nymphoides peltata growing in the Dalsung wetland. The fungal culture filtrates of the endophytic fungi were treated to Waito-c rice seedling to evaluate their plant growth-promoting activities. Culture filtrate of Y2H0002 fungal strain promoted the growth of the Waito-c rice seedlings. This strain was identified on the basis of sequences of the partial internal transcribed spacer region and the partial beta-tubulin gene. Upon chromatographic analysis of the culture filtrate of Y2H0002 strain, the gibberellins (GAs: $GA_1$, $GA_3$, and $GA_4$) were detected and quantified. Molecular and morphological studies identified the Y2H0002 strain as belonging to Aspergillus clavatus. These results indicated that A. clavatus improves the growth of plants and produces various GAs, and may participate in the growth of plants under diverse environmental conditions.

• The Plant Pathology Journal
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• 제38권1호
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• pp.33-45
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• 2022

To screen antagonistic fungi against plant pathogens, dual culture assay (DCA) and culture filtrate assay (CFA) were performed with unknown soil-born fungi. Among the different fungi isolated and screened from the soil, fungal isolate ANU-301 successfully inhibited growth of different plant pathogenic fungi, Colletotrichum acutatum, Alternaria alternata, and Fusarium oxysporum, in DCA and CFA. Morphological characteristics and rDNA internal transcribed spacer sequence analysis identified ANU-301 as Aspergillus terreus. Inoculation of tomato plants with Fusarium oxysporum f. sp. lycopersici (FOL) induced severe wilting symptom; however, co-inoculation with ANU-301 significantly enhanced resistance of tomato plants against FOL. In addition, culture filtrate (CF) of ANU-301 not only showed bacterial growth inhibition activity against Dickeya chrysanthemi (Dc), but also demonstrated protective effect in potato tuber against soft rot disease. Gas chromatography-tandem mass spectrometry analysis of CF of ANU-301 identified 2,4-bis(1-methyl-1-phenylethyl)-phenol (MPP) as the most abundant compound. MPP inhibited growth of Dc, but not of FOL, in a dose-dependent manner, and protected potato tuber from the soft rot disease induced by Dc. In conclusion, Aspergillus terreus ANU-301 could be used and further tested as a potential biological control agent.

• The Plant Pathology Journal
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• 제22권3호
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• pp.289-294
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• 2006

Two isolates of mucous bacteria, mc75 and pc78, were isolated from fungal culture plate as culture contaminants with an interesting swarming motility. Both isolates were identified as Pseudomonas fluorescens based on microscopy, biochemical analysis, Biolog test and DNA sequence analysis of the 16S rRNA gene. Both strains have the exactly the same 16S rRNA gene sequences, and yet their biological control activity were not identical each other. In vitro analysis of antagonistic activity of two isolates against several plant pathogenic fungi indicated that both produced diffusible and volatile antifungal compounds of unknown identities. Treatment of the bacterial culture of P. fluorescens pc78 and its culture filtrate exhibited a strong biological control activity against rice sheath blight in vivo among six plant diseases tested. More effective disease control activity was obtained from treatment of bacterial culture than that of culture filtrate. Therefore, in addition to antifungal compound and siderophore production, other traits such as biofilm formation and swarming motility on plant surface may contribute to the biological control activity of P.fluorescens pc78 and mc75.

• Applied Biological Chemistry
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• 제36권5호
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• pp.352-357
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• 1993

S.G.Y.배지(skim milk, glucose, yeast extract)와 S.M.W.배지(skim milk whey). 배지에 P. freudenreichii KFCC 31227과 L. acidophilus KFCC 32825를 단독 또는 혼합배양 후, 두 균주의 생육 및 유기산 생성에 미치는 발효여액의 영향과 당의 변화 및 이용 효과를 검토한 결과, 자신의 발효여액보다는 상대편의 발효여액에서 그리고 단독배양보다는 혼합배양에서 생육이나 산 생성의 효과가 촉진되었으며, 배지중의 glucose 및 lactose 의 이용효과를 보면 P. freudenreich-ii KFCC 31227 단독 배양시는 lactose 를, L. acdophilus KFCC 32825 단독배양시는 glucose를 생육이나 산 생성에 더 잘 이용하였다. 또한 두 균주의 혼합배양시에는 단독배양에 비해 발효에 glucose 나 lactose 를 이용하는 시간이 더욱 단축되는 결과로 나타났으며, 이것은 혼합배양시 두 균주의 상호작용에 의한 synergism 효과에 기인된 것으로 생각된다.

• International Journal of Industrial Entomology and Biomaterials
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• 제35권1호
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• pp.58-62
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• 2017

The two-spotted spider mite (Tetranychus urticae) has sustained damage on more than 200 host plants worldwide. Many farmers have relied on chemical acaricides to control mite, but the abuse of acaricides has caused serious resistance to mite. To overcome this problem, microbial control using entomopathogenic fungi have been studied. Entomopathogenic fungi have been an important role against the control of pest, and most of their culture products have been demonstrated to have virulence against pest population. In this study, we evaluated and compared the virulence of culture filtrates, aerial conidia and blastospores of selected Metarhizium anisopliae 4-2 and Beauveria bassiana 2R-3-3-1, respectively, among two-spotted spider mite-pathogenic fungi. As a result, the virulence was confirmed in all treatments, and the accumulated mortality rates were between 77 and 100% within 7 days. Especially, treatment with the fungal culture filtrate alone exhibited quite high virulence, and combined treatment with aerial conidia or blastospores enhanced activity. However, the median lethal time of treatments was not significantly different. When two isolates were compared, M. anisopliae 4-2 showed higher virulence than B. bassiana 2R-3-3-1. These results suggest that the selected two fungal isolates and their culture products could be used effectively for the control of two-spotted spider mite.

• Weed & Turfgrass Science
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• 제2권2호
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• pp.202-206
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• 2013

Helicosporium spp.의 식물병원균 Rhizoctonia solani와 Fusarium oxysporium, Phytophthora drechsleri에 대한 항균 활성을 실내와 야외에서 검정하였다. Helicosporium 0635BP 균주는 Rhizoctonia solani와 Fusarium oxysporium에 대해 PDA배지상에서 강한 균사억제 효과를 보였다. 살균한 배양여액 50 ml/L 처리 시 잔디 갈색퍼짐병균(Rhizoctonia solani AG2-2)에 대한 높은 생장억제효과를 보였다. 배양여액 20%에 4시간 동안 침지하거나 50% 배양여액에 1시간 침지 시 Rhizoctonia solani AG2-2 IV는 100% 사멸하였다. 골프장 들잔디에서 Helicosporium 0635BP 균주의 배약여액 처리 시 10배액까지 잔디 갈색퍼짐병의 병 진전을 대조약제와 동일하게 100% 억제하였다. 따라서 Helicosporium 0635BP 배양액은 잔디 갈색퍼짐병의 생물적 방제인자로 활용가능 할 것으로 생각되며 실용화를 위하여 대량배양과 항균 물질의 정제와 동정이 필요할 것으로 보인다.