• Journal of Microbiology and Biotechnology
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• 제25권5호
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• pp.620-628
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• 2015

A fungal strain, R9, was isolated from the South Atlantic sediment sample and identified as Aspergillus fumigatus. An antifungal protein, AfAFP_R9, was purified from the culture supernatant of Aspergillus fumigatus R9. AfAFP_R9 was identified to be restrictocin, which is a member of the ribosome-inactivating proteins (RIPs), by MALDI-TOF-TOF-MS. AfAFP_R9 displayed antifungal activity against plant pathogenic Fusarium oxysporum, Alternaria longipes, Colletotrichum gloeosporioides, Paecilomyces variotii, and Trichoderma viride at minimum inhibitory concentrations of 0.6, 0.6, 1.2, 1.2, and 2.4 μg/disc, respectively. Moreover, AfAFP_R9 exhibited a certain extent of thermostability, and metal ion and denaturant tolerance. The iodoacetamide assay showed that the disulfide bridge in AfAFP_R9 was indispensable for its antifungal action. The cDNA encoding for AfAFP_R9 was cloned from A. fumigatus R9 by RT-PCR and heterologously expressed in E. coli. The recombinant AfAFP_R9 protein exhibited obvious antifungal activity against C. gloeosporioides, T. viride, and A. longipes. These results reveal the antifungal properties of a RIP member (AfAFP_R9) from marine-derived Aspergillus fumigatus and indicated its potential application in controlling plant pathogenic fungi.

• 미생물학회지
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• 제48권1호
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• pp.16-21
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• 2012

여러 식물의 근권에서 세균 균주들을 분리하여 이들의 항진균성 물질 생성능을 조사하였다. 분리균주 중 Fusarium oxysproum을 포함한 5가지 주요 식물병원성 진균에 대한 생장저해가 우수한 7개 균주를 16S rRNA 유전자 염기서열로 동정하였다. 이들 중 Paenibacillus peoriae RhAn32, Pseudomonas otitidis TK1과 Bacillus cereus TK2가 가장 넓은 생장 저해범위를 나타내었으며 항진균성 물질 중 siderophore 생성능은 P. otitidis TK1이 3.21 mM/ml로 가장 높았고 HCN은 Pseudomonas koreensis Rh2와 Rh7 균주만이 생성하였으며 Brevibacterium frigoritolerans EnA9와 P. peoriae RhAn32는 각각 1558.9와 $1436.7{\mu}M$ glucose/min/mg protein의 높은 chitinase 활성을 나타내었다. P. otitidis TK1과 P. peoriae RhAn32의 항진균능을 진균과의 공동배양을 통해 정량분석한 결과 세 종류의 Fusarium oxysproum의 생장을 유의성 있게 저해하였다. P. otitidis TK1은 식물생장을 촉진하는 호르몬인 auxin의 생성능도 가장 높았는데 이 균주를 4주 자란 토마토 유묘에 F. oxysporum f. sp. lycopersici와 동시에 접종하여 8주간 재배하였을 때 줄기와 뿌리 길이 및 습윤 중량이 비접종 대조군에 비해 각각 45.7, 64.9와 118%로 유의성 있게 증가하였다. 따라서 이 균주들은 유기합성농약을 대체하면서 식물생장을 촉진하는 미생물제로서의 적용이 가능할 것으로 기대된다.

• Journal of Applied Biological Chemistry
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• 제64권4호
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• pp.333-341
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• 2021

본 연구는 근권 토양 및 뿌리에 존재하는 근권 미생물 중 미생물 제제로 적합한 균주를 선별하기 위해서 미네랄 가용화능, 10종의 식물 병원성 곰팡이에 대한 항진균 활성 및 식물 생장 촉진 활성을 평가하였다. 결과적으로 불용성 인산, 탄산칼슘, 규소 및 아연 가용화능과 질소고정능, siderophore, indole-3-acetic acid와 aminocyclopropane-1-carboxylate deaminase 생성능 및 7종의 식물 병원성 곰팡이에 대해 항진균 활성을 갖는 DDP346을 선별하였다. 선별된 DDP346은 Acinetobacter pittii DSM21653 (NR_117621.1)와 99.9% 이상의 높은 상동성을 보였으며, 16S rRNA 염기서열을 바탕으로 계통도를 분석한 결과에서도 Acinetobacter pittii와 높은 유연관계를 나타내었다. DDP346의 생장 조건은 온도(10-40 ℃), pH (5-11) 염농도(0-5%) 범위로 확인하였다. 또한 pH 변화와 가용화된 인산 함량 간에 음의 상관계수(r²= -0.913, p <0.01)를 나타내는 것을 확인하였는데, 이는 배양 중에 생성되는 유기산에 의한 것으로 추정된다. 결과적으로 미네랄 가용화능, 식물 병원성 곰팡이에 대한 항진균 활성 및 식물 생장 촉진 활성 평가를 통해 Acinetobacter sp. DDP346을 다목적 미생물 제제로써 활용 가능성을 제시한다.

• Journal of the Korean Wood Science and Technology
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• 제38권4호
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• pp.341-348
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• 2010

목초액의 농약 또는 식품보존제로서의 이용 가능성을 검토하기 위하여 소나무 및 참나무류 기계식 목초액을 대상으로 항진균 및 항세균 활성을 검정하였다. 그 결과 항진균활성의 경우 미정제 목초액은 0.5% 이상의 농도 에서, 정제 목초액은 1.0% 이상의 농도에서 공시 식물병원균 및 목재부후균의 생장을 완전히 억제하여 미정제 목초액이 정제 목초액보다 항균활성이 높은 것으로 나타났다. 그리고 참나무류 목초액이 소나무 목초액보다 항 균활성이 높아 탄화 원료인 수종에 따라 항균활성의 차이가 있음을 알 수 있었다. 균종별로는 표고 해균인 주홍 꼬리버섯에 대한 항균효과가 다른 공시 균주에 비해 높은 것으로 나타나 균의 종류에 따라 목초액에 대한 감수성이 차이가 있는 것으로 밝혀졌다. 한편, 식품부패균 및 식중독균에 대한 항세균활성을 검정한 결과 소나무 및 참나무류 미정제 목초액의 경우 10% 농도에서 모든 공시 균주에 대해 생육저지환을 형성한 반면 정제 목초액 의 경우에는 저지환을 형성하지 않아 항세균활성도 미정제액이 정제액보다 높은 것으로 나타났다. 균종에 따른 감수성에도 차이가 있어 그람 양성균에 대한 항균활성이 그람 음성균에 비해 상대적으로 높았으나 탄화 원료에 의한 차이는 뚜렷하게 나타나지 않았다. 이상의 결과 목초액은 식물병원균, 목재부후균, 식품부패균 및 식중독 균에 대한 항균활성이 우수하여 유기합성 농약을 대체하거나 식품의 부패를 막기 위한 식품보존제로서 이용이 가능할 것으로 판단되었다.

• 한국자원식물학회:학술대회논문집
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• 한국자원식물학회 2002년도 제9차 국제심포지움 및 추계정기학술발표회
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• pp.55-55
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• 2002

Occurrences of diseased sweet flag (Acorus calamus L. var. asiaticus) were found in Chonju and Buan Province, on August 2002. The typical symptoms of the disease affected the leaves, pods, and collar of the infected plants. The leaves or pods became darker brown, then dry rotted, and white fluffy mycelia formed on the lesion. The collar, of the infected plants, formed black spot. The spores grew rapidly on PDA medium. Pathogenic fungi have not been identified clearly, as of yet. These fungi were formed from developed spores, as well as, undeveloped spores. These fungi suggest that Fusarium sp. and Rhizoctonia sp.. The range of temperatures were tested from 5$^{\circ}C$ to 35$^{\circ}C$ for mycelial growth. The optimum temperature for growth was 3$0^{\circ}C$. This is the first report on the fungus disease of sweet flag by some pathogens, in Korea. We would like to do further research for single spore isolation, pathogenity, and characterization of fungi.

• The Plant Pathology Journal
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• 제28권1호
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• pp.10-19
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• 2012

This study investigated the distribution of endophytic fungi obtained from the surface sterilized tissues of leaves, stems and roots of chili pepper ($Capsicum$ $annuum$ L.) plants in seedling, flowering and fruiting stages in Korea and their antifungal activity. A total of 481 isolates were recovered and were identified using molecular techniques. Based on rDNA ITS gene sequence and phylogenetic analysis, 21 fungal genera were characterized, belonging to 16 Ascomycota and 5 Basidiomycota. $Penicillium$ in seedling stage, $Fusarium$ in flowering stage, $Colletotrichum$ followed by $Fusarium$, $Alternaria$ and $Xylaria$ in fruiting stage was predominant and $Alternaria$, $Cladosporium$ and $Fusarium$ were common in all growth stages. Among 481 endophytes 90 phenotypes were evaluated for the antimicrobial activity against three major pathogens ($Phytophthora$ $capsici$, $Colletotrichum$ $acutatum$ and $Fusarium$ $oxysporum$) of chili pepper. Among them 16 isolates inhibited the growth of at least one test microorganisms. Three strains showed a broad spectrum antifungal activity and displayed strong inhibition against chili pepper pathogenic fungi.

• 한국식물병리학회:학술대회논문집
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• 한국식물병리학회 2005년도 한국식물병리학회 임시총회 및 춘계학술발표회
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• pp.88.2-89
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• 2005

• The Plant Pathology Journal
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• 제36권3호
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• pp.231-243
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• 2020

Rice blast, caused by Magnaporthe oryzae, is one of the most destructive rice diseases worldwide. The aim of this study was to screen bacterial isolates to efficiently prevent the occurrence of rice blast. A total of 232 bacterial isolates were extracted from nonrhizospheric rice soil and were screened for antifungal activity against M. oryzae using a leaf segment assay. Strains S170 and S9 showed significant antagonistic activity against M. oryzae in vitro and in leaf disk assays, and controlled M. oryzae infection under greenhouse conditions. The results showed that strains S170 and S9 could effectively control rice leaf blast and panicle neck blast after five spray treatments in field. This suggested that the bacterial strains S170 and S9 were valuable and promising for the biocontrol of rice disease caused by M. oryzae. Based on 16S rDNA, and gyrA and gyrB gene sequence analyses, S170 and S9 were identified as Bacillus amyloliquefaciens and B. pumilus, respectively. The research also demonstrated that B. amyloliquefaciens S170 and B. pumilus S9 could colonize rice plants to prevent pathogenic infection and evidently suppressed plant disease caused by 11 other plant pathogenic fungi. This is the first study to demonstrate that B. amyloliquefaciens and B. pumilus isolated from nonrhizospheric rice soil are capable of recolonizing internal rice stem tissues.

• The Plant Pathology Journal
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• 제22권1호
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• pp.94-96
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• 2006

In a search for plant extracts with potent in vivo antifungal activity against various plant pathogenic fungi, the methanol extract of the Curcuma longa rhizomes effectively controlled the development of rice blast catised by Magnaporthe grisea and tomato late blight caused by Phytophthora infestans. Three curcuminoids such as curcumin, demethoxycurcumin, and bisdemethoxycurcumin were purified from the methanol extract of C. longa rhizomes as antifungal principles. Among the three curcuminoids, demethoxycurcumin was the most active to both rice blast and tomato late blight, followed in order by curcumin and bisdemethoxycurcumin. However, they all exhibited no or little in vivo antifungal activity against other fungal pathogens causing rice sheath blight (Corticium sasaki), tomato gray mold (Botrytis cinerea), wheat leaf rust (Puccinia recondita), or barley powdery mildew (Blumeria graminis f. sp. hordel).

• The Plant Pathology Journal
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• 제20권2호
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• pp.115-126
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• 2004

The actinomycete strain PK-A41 was isolated from a soil sample from pepper fields in Ko-yang, Korea. The strain PK-A41 inhibited the mycelial growth of some plant pathogenic fungi and oomycete, Alternaria mali, Colletotrichum orbiculare, Fusarium oxysporum f.sp. lycopersici, Magnaporthe grisea, Rhizoctonia solani, and Phytophthora capsici. The presence of LL-diaminopi-melic acid in the cell wall extract and the nucleotide sequence of the 16S rDNA region of the strain PK-A41 was assigned to Streptomyces scabiei. Further morpho-logical, biochemical, and pathological analyses also confirmed the strain PK-A41 to be S. scabiei, which is pathogenic to potato tubers. The maximum antibiotic production of the strain PK-A41 was achieved when grown on the glycerol peptone broth (GPB) medium for 9 days.