• Mycobiology
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• v.39 no.1
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• pp.7-11
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• 2011

Shimizuomyces paradoxus showed no inhibitory effect against plant pathogen fungi, such as Fusarium oxysporum f. sp. lycopersici and Alternaria solani. The S. paradoxus culture filtrate showed higher seed germination and seedling growth rates in canola than distilled water and potato-dextrose broth. A conidial suspension of $1.0{\times}10^4/mL$ resulted in the highest growth stimulating effects on total plant length, and fresh and dry weight of shoots and roots in cucumber, when compared to the highest suspension concentration. Total plant length and shoot weight increased with the foliar spray treatment, and root length and root weight increased by simultaneous treatments of soil drenching and foliar spray in cucumber. Lower concentrations of the S. paradoxus conidial suspension increased the harvest of tomato fruit.

• Korean Journal Plant Pathology
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• v.10 no.3
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• pp.240-244
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• 1994

Watermelon plants grafted with the root-stock of wild-cucumber (Sicyos angulatus) were not infected by Fusarium oxysporum f.sp. niveum in pot inoculation and infected fields tests. Controlling efficacy of the root-stock grafting with S. angulatus on Fusarium wilt of watermelon was more excellent than that of the root-stock grafting with Lagenaria siceraria. The isolates of Fusarium oxysprum from cucurbitaceae plants had a certain host-specific pathogenicity, but they did not express the absolute one forma specialis-one host-plant phenomenon by the root dipping inoculation. The pathogenic isolates of Fusarium oxysproum from cucurbitaceae crops did not infect the root-stock plant such as S. angulatus, L. siceraria and Cucurbita ficifolia. The fast-wilting of watermelon caused by uncertain agents was observed in watermelon plant grafted with L. siceraria in the continuously cropping fields, but it was not observed in watermelon plants grafted with S. angulatus in the same fields.

• Microbiology and Biotechnology Letters
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• v.27 no.3
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• pp.191-196
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• 1999

A multifunctional antagonistic bacterium, producing both antifungal antibiotic and chitinase that could be used as biocontrol agents against fungal plant pathogens was isolated from the plant-disease suppressive soil. The isolate was identified as Promicromonospora sp. KH-28 from various morphological, biochemical and physiological tests. The antifungal antibiotic produced by Promicromonospora sp. KH-28 was soluble in n-butanol, methanol, toluene, n-hexane, ethanol but insoluble in H2O, acetone, chloroform, ethylacetate and ethylether. It inhibited the growth of fungal plant pathogens of Fusarium solani, F. oxysporum, Alternaria mali and Phytophthora capsici. The antagonistic Promicromonospora sp. KH-28 produced optimally the antifungal antibiotic when it was cultivated at pH 7, 3$0^{\circ}C$ for 5 days.

• The Plant Pathology Journal
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• v.25 no.2
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• pp.199-204
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• 2009

Three plant growth-promoting yeasts and two rhizobacteria were tested for controlling tomato wilt caused by Fusarium oxysporum f. sp. lycopersici under green-house and field conditions. Under greenhouse and field conditions, all treatments were significantly reduced disease severity of tomato wilt relative to the infected control. The highest disease reductions in pots (75.0, 67.4%) and field (52.5, 42.4%) were achieved by Azospirillum brasilense and Bacillus subtilis compared to infected control. Under field condition all treatments produced the highest tomato yield compared to the control plants inoculated with the pathogen.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1998.11a
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• pp.174-174
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• 1998

Twelve different derivatives were synthesised from chitin/chitosan[1, 2, 3]. Their structures have been determined by different physical methods. The bioassay screening on antifungal and antibacterial activities of all these compounds showed that most of them had significant activity and they can inhibite the growth of some fungi and bacterias : E. coli, S. pyogenes, F. oxysporum, P. oryzae, that caused the spoilage of fresh fruits and foods. Furthermore, all of these compounds are non-toxic (LD$\_$50/>50g/kg) and can be applied for food preservation.

• Research in Plant Disease
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• v.14 no.1
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• pp.76-78
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• 2008

During the investigation of Allium decline in Pohang, Korea, root-knot nematode was found from root of Allium tuberosum Roth. It was identified as Meloidogyne incognita and was first reported from Allium tuberosum. Allium decline was associated with root-knot nematode, root mite and Fusarium sp. but root-knot nematode appeared to be the main cause of Allium decline.

• Mycobiology
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• v.49 no.5
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• pp.498-506
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• 2021

An endophytic fungus strain DYSJ3 was isolated from a stem of Aphanamixis grandifolia Blume, which was identified as Aspergillus versicolor based on the morphological characteristics, internal transcribed spacer (ITS) and calmodulin gene sequences analyses. A. versicolor DYSJ3 exhibited strong antagonistic activity against Colletotrichum musae, C. gloeosporioides and Fusarium oxysporum f. sp. cubense with the inhibition rates of 61.9, 51.2 and 55.3% respectively. The antifungal metabolites mainly existed in the mycelium of A. versicolor DYSJ3, and its mycelial crude extract (CE) had broad-spectrum antifungal activities against plant pathogenic fungi. The CE had a good thermal stability, and the inhibition rate of 100 mg/mL CE against C. musae was above 70.0% after disposing at 120 ℃ for 1 h. Five secondary metabolites were isolated from the CE and identified as averufanin, ergosterol peroxide, versicolorin B, averythrin and sterigmatocystin. Activity evaluation showed versicolorin B exhibited inhibitory effects on the mycelial growth and conidial germination of C. musae, and sterigmatocystin had a weak inhibitory effect on the mycelial growth of C. musae.

• The Korean Journal of Mycology
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• v.25 no.4 s.83
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• pp.354-361
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• 1997

The antifungal activities of 153 extracts from 51 species of Korean mushroom on six phytopathogenic fungi were investigated. The powder of fruit-body of each mushroom was extracted with petroleum ether, 80% ethanol and distilled water. The water extracts of four mushrooms including Amanita virosa showed antifungal activities on Alternaria alternata, Colletotrichum graminicola, Fusarium solani, Idriella bolleyie. The 80% ethanol extracts of seven mushrooms including Boletus auripes showed antibiotic activities against A. alternata, C. gramincola, Cylindrocarpon destructans, F. solani, F. oxysporum cucumerinum, and I. bolleyie. The petroleum ether extracts of six mushrooms including Amanita citrina showed antibiotic activities against A. alternata, C. destructans, and C. graminicola. The 102 extracts of 34 mushrooms including Agaricus arvensis didn't show antibiotic activities.

• The Plant Pathology Journal
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• v.19 no.3
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• pp.129-132
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• 2003

Fusarium wilt of cucumber caused by Fusarium oxy-sporum f. sp. cucumerinum is a serious vascular disease worldwide. Biological control of Fusarium wilt in several crops has been accomplished by introducing non-pathogenic Fusarium sup. and other biocontrol agents in soil or in infection courts. In this study, quantitative models were used to determine the biocontrol efficacy of inundatively applied antagonist formulations and the length of their effectiveness in controlling Fusarium wilt of cucumber. Quantitative model of the form [Y=L (1${-exp}^{-kx}$)] best described the relationship between disease incidence (Y, %) and inoculum density (X) of isolates F51 and F55. Isolate F51 was selected as a more virulent isolate based on the extent of its effectiveness in causing the wilt disease. The degree of disease control (Xi/X) obtained with the density of the biocontrol agent (Z), was described by the model [Xi/X=A (1${-exp}^{-cz}$)]. The zeolite-based antagonist formulation amended with chitosan (ZAC) was better at lower rates of application and peaked at around 5 g/ kg of the potting medium, whereas the peat-based antagonist formulation (PA) peaked at around 10 g/kg of the potting medium. ZAC formulation provided significantly better suppression of Fusarium wilt as described by the curvilinear relationship of the type Y= a+bX+c$X^2$, where Y represents percent disease incidence and X represents sustaining effect of the biocontrol agent.

• Journal of Microbiology and Biotechnology
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• v.33 no.4
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• pp.543-551
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• 2023

In this study, five endophytic fungi belonging to the Aspergillus and Alternaria genera were isolated from Lagopsis supina. The antimicrobial activity of all fungal fermented extracts against Staphylococcus and Fusarium graminearum was tested using the cup-plate method. Among them, Aspergillus ochraceus XZC-1 showed the best activity and was subsequently selected for large-scale fermentation and bioactivity-directed separation of the secondary metabolites. Four compounds, including 2-methoxy-6-methyl-1,4-benzoquinone (1), 3,5-dihydroxytoluene (2), oleic acid (3), and penicillic acid (4) were discovered. Here, compounds 1 and 4 displayed anti-fungal activity against F. graminearum, F. oxysporum, F. moniliforme, F. stratum, Botrytis cinerea, Magnaporthe oryzae, and Verticillium dahlia with diverse MIC values (128-512 ㎍/ml), which were close to that of the positive control antifungal, actidione (64-128 ㎍/ml). Additionally, compounds 1 and 4 also exhibited moderate antibacterial activity against S. aureus, Listeria monocytogenes, Escherichia coli, and Salmonella enterica, with low MIC values (8-64 ㎍/ml). Moreover, compounds 1 and 4 displayed selective cytotoxicity against cancer cell lines as compared with the normal fibroblast cells. Therefore, this study proposes that the endophytic fungi from L. supina can potentially produce bioactive molecules to be used as lead compounds in drugs or agricultural antibiotics.