• Journal of Ginseng Research
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• v.45 no.1
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• pp.156-162
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• 2021

Background: It is estimated that 20-30% of ginseng crops in Canada are lost to root rot each harvest. This disease is commonly caused by fungal infection with Ilyonectria, previously known as Cylindrocarpon. Previous reports have linked the virulence of fungal disease to the production of siderophores, a class of small-molecule iron chelators. However, these siderophores have not been identified in Ilyonectria. Methods: High-resolution LC-MS/MS was used to screen Ilyonectria and Cylindrocarpon strain extracts for secondary metabolite production. These strains were also tested for their ability to cause root rot in American ginseng and categorized as virulent or avirulent. The differences in detected metabolites between the virulent and avirulent strains were compared with a focus on siderophores. Results: For the first time, a siderophore N,N',N"-triacetylfusarinine C (TAFC) has been identified in Ilyonectria, and it appears to be linked to disease virulence. Siderophore production was suppressed as the concentration of iron increased, which is in agreement with previous reports. Conclusion: The identification of the siderophore produced by Ilyonectria gives us further insight into the root rot disease that heavily affects ginseng crop yields. This research identifies a molecular pathway previously unknown for ginseng root rot and could lead to new disease treatment options.

• Journal of Microbiology and Biotechnology
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• v.18 no.4
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• pp.648-657
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• 2008

In this study, we used functional genomic strategies, proteomics and quantitative real-time (qRT)-PCR, to advance our understanding of genes associated with fumonisin production in the fungus Fusarium verticillioides. Earlier studies have demonstrated that deletion of the FCC1 gene, which encodes a C-type cyclin, leads to a drastic reduction in fumonisin production and conidiation in the mutant strain (FT536). The premise of our research was that comparative analysis of F. verticillioides wild-type and FT536 proteomes will reveal putative proteins, and ultimately corresponding genes, that are important for fumonisin biosynthesis. We isolated proteins that were significantly upregulated in either the wild type or FT536 via two-dimensional polyacrylamide gel electrophoresis, and subsequently obtained sequences by mass spectrometry. Homologs of identified proteins, e.g., carboxypeptidase, laccase, and nitrogen metabolite repression protein, are known to have functions involved in fungal secondary metabolism and development. We also identified gene sequences corresponding to the selected proteins and investigated their transcriptional profiles via quantitative real-time (qRT)-PCR in order to identify genes that show concomitant expression patterns during fumonisin biosynthesis. These genes can be selected as targets for functional analysis to further verify their roles in $FB_1$ biosynthesis.

• International Journal of Industrial Entomology and Biomaterials
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• v.18 no.2
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• pp.125-129
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• 2009

Entomopathogenic fungi were isolated directly from a cadaver of adult Monochamus alternatus supporting fungal sporulation, using a semi-selective medium and then screened several fungal colonies. The pathogenicity of each fungus was tested using oak longicorn beetle, Moechotypa diphysis, as substitutive insect. As the result, only one of them showed high pathogenicity against M. diphysis, with up to 100% mortality within 21 days of inoculation. Selected fungus was named as MaW1 and identified by Beauveria bassiana using microscopic examination and DNA analysis. Pathogenicity was also evaluated to M. alternatus.

• The Korean Journal of Mycology
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• v.41 no.1
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• pp.9-13
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• 2013

In this study, roots of Epipactis thunbergii were collected from Chujado on the north of Jeju-do. Six fungal isolates were isolated from surface-sterilized roots of the orchid and classified with groups based on morphological characteristics. Fungal DNA was extracted from each isolate and amplified ITS region using ITS1-OF/ITS4-OF primer pair. Three species of orchid mycorrhizal fungi were identified as Tulasnella calospora, Tulasnella sp. and Sebacina sp. based on molecular and morphological characteristics.

• The Plant Pathology Journal
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• v.26 no.1
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• pp.32-36
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• 2010

Twelve fungal isolates out of 123 isolates obtained from cysts and soils of potato cyst nematode (PCN)-infested fields in Central Java, Indonesia had parasitic abilities of over 50% on PCN eggs or females (cysts) in vitro pathogenicity tests. Cultural and morphological characters and DNA sequences of ribosomal genes in ITS region revealed that they were four isolates of Gliocladium (Trichoderma) virens, three isolates of Fusarium oxysporum, one of F. lateritium, one of Penicillium tritinum and two of Taralomyces spp. A hundred percent infections occurred in eggs or cysts by three fungal isolates G. virens, F. oxysporum and P. oxalicum, suggesting that these fungi may have a good potential for the PCN biocontrol. Especially, G. virens isolates, which occurred most frequently in the PCN-infested potato fields and are known to be highly adaptable to varying habitats, may be developed as reliable agents for controlling PCN with both egg- and cyst-parasitic capabilities and with high ecological adaptabilities.

• Microbiology and Biotechnology Letters
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• v.46 no.1
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• pp.68-76
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• 2018

Actinobacterial strains isolated from Cow feces were studied for their antifungal attributes against phytopathogens and industrially important enzymes. A total of 30 Actinobacterial strains were obtained from 10 samples of cow feces. All the strains were belonging to the genera Streptomyces on the basis of morphological and chemotaxonomic analysis. During preliminary screening, out of 30 strains, 15 strains (50%) showed antifungal activity against five fungal phytopathogens including Aspergillus niger, Fusarium solani, Fusarium oxysporum, Macrophomina phaseolina and Rhizoctonia solani. While, isolate GBTCF-26 was found to be most active against R. solani with 62.2% inhibition of fungal mycelium, GBTCF-09 was prominent against F. solani and F. oxysporum with percent inhibition of 61.1% and 58.8%, respectively. Out of 30 strains, 19 (63.3%), 16 (53.3%), 11 (36.7%), 10 (33.3%), 4 (13.3%) and 8 (26.7%) strains were producing amylase, caseinase, gelatinase, lipase, chitinase and cellulose, respectively. The selected strains, GBTCF-09, GBTCF-21 and GBTCF-26, were identified as Streptomyces sp. on the basis of their 16S rDNA sequence. The study supports the idea that the Actinobacteria from unique niches (Cow feces) possess the production potential of industrially important enzymes including bioactive molecules.

• Journal of Microbiology and Biotechnology
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• v.25 no.3
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• pp.353-357
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• 2015

A new actinomycete strain NA4 was isolated from a deep-sea sediment collected from the South China Sea and showed promising antifungal activities against soilborne fungal pathogens. It was identified as Streptomyces cavourensis by morphological, physiological, and phylogenetic analyses based on its 16S rRNA gene sequence. The main antifungal components were isolated and identified from the fermentation culture as bafilomycins B1 and C1. These compounds exhibited significant antifungal activities and a broad antifungal spectrum. The results suggest that the Streptomyces cavourensis NA4 and bafilomycins B1 and C1 could be used as potential biocontrol agents for soilborne fungal diseases of plants.

• The Korean Journal of Pesticide Science
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• v.13 no.4
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• pp.332-335
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• 2009

Rhizo-bacteria were isolated from organic-farming soils to select antagonistic agent for controlling citrus melanose disease. Among several antagonistic bacteria, KB-401 effectively inhibited mycelial growth of several plant fungal pathogens, including the pathogen of citrus melanose, Diaporthe citri. KB-401 also inhibited spore germination of the fungal pathogen. The tip of germ tube was swollen when conidia of D. citri were co-culture with KB-401 in PD broth amended 1% glucose. KB-401 was identified as Bacillus subtilis through the investigation for physiological characters and the analysis of nucleotide sequences of 16S rDNA.

• Journal of Microbiology and Biotechnology
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• v.24 no.10
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• pp.1337-1345
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• 2014

A novel antifungal protein produced by the fungal strain Penicillium citrinum W1, which was isolated from a Southwest Indian Ocean sediment sample, was purified and characterized. The culture supernatant of P. citrinum W1 inhibited the mycelial growth of some plant pathogenic fungi. After saturation of P. citrinum W1 culture supernatants with ammonium sulfate and ion-exchange chromatography, an antifungal protein (PcPAF) was purified. The N-terminal amino acid sequence analysis showed that PcPAF might be an unknown antifungal protein. PcPAF displayed antifungal activity against Trichoderma viride, Fusarium oxysporum, Paecilomyces variotii, and Alternaria longipes at minimum inhibitory concentrations of 1.52, 6.08, 3.04, and $6.08{\mu}g/disc$, respectively. PcPAF possessed high thermostability and had a certain extent of protease and metal ion resistance. The results suggested that PcPAF may represent a novel antifungal protein with potential application in controlling plant pathogenic fungal infection.

• The Korean Journal of Mycology
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• v.46 no.3
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• pp.249-254
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• 2018

Nannizziopsis mirabilis (KNU17-67) was isolated from a field soil sample collected from Jejudo in 2017. This fungal isolate was identified and described by its morphological characters and the internal transcribed spacer rDNA gene sequencing. Potato dextrose agar medium was used to study its macro and micromorphology. In addition, a molecular phylogenetic tree was constructed for its precise confirmation as N. mirabilis. This fungal isolate has not officially been reported previously in Korea.