• The Korean Journal of Mycology
• /
• v.50 no.3
• /
• pp.183-194
• /
• 2022

Two fungal strains, designated KNUF-21-006 and KNUF-21-028, were isolated from soil samples collected from Gyeongbuk Province, Korea. The strain KNUF-21-006 was similar to other Pestalotiopsis species in terms of morphological characteristics, including whitish to pale brown mycelium, conidial shape, and size. The isolate had aerial hyphae that produced black fruiting bodies on the mycelium. The conidia were fusoid to ellipsoid, four-septate, and appendage-bearing. Phylogenetic analysis using the internal transcribed spacer (ITS) region, translation elongation factor 1-alpha (TEF), and β-tubulin (TUB) gene sequences confirmed that the closest relationship of the isolate at the species level was with Pestalotiopsis clavata. The strain KNUF-21-028 exhibits similar morphological characteristics to other Botryotrichum species, including white aerial mycelium with sulcate and irregular margins, conidial shape, and size. The conidia were globose, single, and hyaline. Upon molecular analysis-using the ITS region, large subunit (LSU) rRNA gene, and TUB gene sequences-the fungus was identified as Botryotrichum iranicum. This is the first record of these fungal species in Korea.

• Mycobiology
• /
• v.45 no.1
• /
• pp.1-8
• /
• 2017

Despite the huge worldwide diversity of Trichoderma (Hypocreaceae, Ascomycota), only about 22 species have been reported in Korea. Thus, between 2013 and 2015, soil-derived Trichoderma spp. were isolated to reveal the diversity of Korean Trichoderma. Phylogenetic analysis of translation elongation factor 1 alpha gene was used for identification. Among the soil-derived Trichoderma, Trichoderma albolutescens, T. asperelloides, T. orientale, T. spirale, and T. tomentosum have not been previously reported in Korea. Thus, we report the five Trichoderma species as new in Korea with morphological descriptions and images.

• Mycobiology
• /
• v.38 no.1
• /
• pp.7-12
• /
• 2010

A green mold species that has not previously been reported in Korea was isolated from oak log beds used for shiitake (Lentinula edodes) cultivation that were infested by mushroom flies. In this study, we identify the mold species as Gliocladium viride (an anamorph of Hypocrea lutea) and describe its mycological properties. The fungus was cottony on both potato dextrose agar (PDA) and Czapek yeast extract agar (CYA), but was colored white on PDA and became yellowish green and brown on CYA. Mycelial growth on PDA attained a diameter of 73 mm at $30^{\circ}C$ after 5 days. The fungus grew faster on malt extract agar (> 80 mm, 5 days at $25^{\circ}C$) compared to CYA and PDA (< 68 mm, 5 days at $25^{\circ}C$). Penicillate conidiophores of the fungus are hyaline, smooth walled, branching above typically in four stages, and $120\sim240\;{\mu}m$ in length. Club-shaped or slender phialides are formed on the metulae. Conidia of the fungus were ovate and elliptic, yellowish brown and green, and $2.5\sim3.0\;{\mu}m\times1.8\sim2.3\;{\mu}m$ in size. Typically, slimy conidia are formed in a mass and colored brown to dark green to almost black. The internal transcribed spacer rDNA and translation elongation factor 1 alpha gene sequences of the fungus isolated here show 99% identity with previously identified G. viride strains.

• The Korean Journal of Mycology
• /
• v.46 no.3
• /
• pp.213-225
• /
• 2018

Trichoderma (Hypocreaceae) is one of the most ubiquitous genera worldwide. This genus has an excellent ability to adapt to diverse environments, even under poor nutritional conditions, such as in freshwater. However, little is known about the diversity of Trichoderma species in freshwater environments. In this study, we isolated diverse fungal strains from algae, plant litter, and soil sediment in streams in Korea. The strains were identified based on molecular phylogenetic analyses of internal transcribed spacer (ITS) rDNA and translation elongation factor 1 ($TEF1{\alpha}$) sequences. We also investigated their morphological characteristics by microscopic observation and determination of cultural features on different media. As a result, six Trichoderma species were found in Korea: T. afroharzianum, T. capillare, T. guizhouense, T. paraviridescens, T. reesei, and T. saturnisporum. Interestingly, T. paraviridescens showed both cellulose activity and hypoxia stress tolerance phenotypes, indicating its role as a decomposer in freshwater ecosystems. Our study revealed that freshwater environment could be a good candidate for investigating the species diversity of Trichoderma.

• The Korean Journal of Mycology
• /
• v.46 no.2
• /
• pp.186-192
• /
• 2018

Rapid and accurate detection methods for Colletotrichum coccodes, an anthracnose pathogen of pepper and tomato, were developed using PCR. A specific primer set, coccoTef-F/coccoTef-R, which was constructed by analyzing tef-$1{\alpha}$ genes from 13 species and 22 strains of Colletotrichum, could specifically detect C. coccodes at a level of 10 ng by conventional PCR method and at 10 pg by real-time PCR. The PCR-based methods were also capable of detecting C. coccodes in pepper and tomato seeds artificially infected with the pathogen. The developed PCR methods can be applied for rapid and accurate inspection of C. coccodes in the seeds intended for export or import.

• The Korean Journal of Mycology
• /
• v.46 no.4
• /
• pp.359-367
• /
• 2018

As an effort to explore fungal diversity, fungal survey was undertaken in 2017 in the vicinity of demilitarized zone (DMZ) located in Yeoncheon-gun, Gyeonggi-do, Korea. For the survey, wild plants and soils were sampled and subjected to fungal isolation. A total of 18 genera and 23 species including five unrecorded fungal species, Mortierella sclerotiella, M. sossauensis, M. verticillate, Eupenicillium saturniforme, and Trichoderma hispanicum, were obtained from the survey. This study described their morphological characteristics including colony features formed on media, light microscopic images and molecular characteristics of nucleotide sequences of the internal transcribed spacer (ITS) region, 18S and 28S rDNA, ${\beta}-tubulin$ gene, calmodulin, and translation elongation factor $1{\alpha}$ ($tef1{\alpha}$) nDNA genes.

• Journal of Microbiology and Biotechnology
• /
• v.20 no.11
• /
• pp.1563-1570
• /
• 2010

To construct a highly sensitive detection system for endocrine disruptors (EDs), we have compared the activity of promoters with the n-alkane-inducible cytochrome P450 gene (ALK1), isocitrate lyase gene (ICL1), ribosomal protein S7 gene (RPS7), and the translation elongation factor-1${\alpha}$ gene (TEF1) for the heterologous gene in Yarrowia lipolytica. The promoters were introduced into the upstream of the lacZ or hERa reporter genes, respectively, and the activity was evaluated by ${\beta}$-galactosidase assay for lacZ and Western blot analysis for hER${\alpha}$. The expression analysis revealed that the ALK1 and ICL1 promoters were induced by n-decane and by EtOH, respectively. The constitutive promoter of RPS7 and TEF1 showed mostly a high level of expression in the presence of glucose and glycerol, respectively. In particular, the TEF1 promoter showed the highest ${\beta}$-galactosidase activity and a significant signal by Western blotting with the anti-estrogen receptor, compared with the other promoters. Moreover, the detection system was constructed with promoters linked to the upstream of the expression vector for the hER${\alpha}$ gene transformed into the Y. lipolytica with a chromosome-integrated lacZ reporter gene under the control of estrogen response elements (EREs). It was indicated that a combination of pTEF1p-hER${\alpha}$ and CXAU1-2XERE was the most effective system for the $E_2$-dependent induction of the ${\beta}$-galactosidase activity. This system showed the highest ${\beta}$-galactosidase activity at $10^{-6}\;M\;E_2$, and the activity could be detected at even the concentration of $10^{-10}\;M\;E_2$. As a result, we have constructed a strongly sensitive detection system with Y. lipolitica to evaluate recognized/suspected ED chemicals, such as natural/synthetic hormones, pesticides, and commercial chemicals. The results demonstrate the utility, sensitivity, and reproducibility of the system for identifying and characterizing environmental estrogens.

• The Korean Journal of Mycology
• /
• v.43 no.3
• /
• pp.158-164
• /
• 2015

A total of 509 rice panicle samples were collected at harvest time from fields in 8 provinces from 2010 to 2014. One hundred five grains per sample were plated on potato dextrose agar and 6,658 Fusarium isolates were obtained; among them, 67 were identified as Fusarium armeniacum by sequencing the translation elongation factor $1{\alpha}$ ($EF-1{\alpha}$) and confirmed by their morphological and cultural characteristics. Considerable variation in conidial size, colony color and $EF-1{\alpha}$ sequences was observed among the fungal isolates. The ability of 24 F. armeniacum isolates to produce T-2 and HT-2 toxin in potato sucrose agar was determined using liquid chromatography-mass spectrometry. Twenty one isolates produced T-2 and HT-2 toxin, resulting in varying toxin levels among the isolates. The results show that Korean isolates of F. armeniacum have diversity with respect to morphological, cultural, genetic, and toxigenic properties.

• The Plant Pathology Journal
• /
• v.24 no.4
• /
• pp.417-422
• /
• 2008

Apicidin is a cyclic tetrapeptide produced by some Fusarium species and is known to inhibit Apicomplexan histone deacetylase. The goals of this study were to determine species identity of Fusarium isolate KCTC16676, an apicidin producer, to improve a method for apicidin extraction, and to test phytotoxicity of apicidin and its analogs. We compared sequences of the translation elongation factor 1-alpha (TEF) gene in KCTC16676 with those from isolates representing diverse Fusarium species, which showed that KCTC16676 belongs to the F. semitectum-F. equiseti species complex. To enhance apicidin production, after culturing isolate KCTC16676 on a wheat medium for 3 weeks at $25^{\circ}C$, the culture was extracted with chloroform. Apicidins were purified through a reverse phase $C_{18}$ silica gel column, resulting in 5 g of apicidin, 200 mg of apicidin A, and 300 mg of apicidin $D_2$ from 4 kg of wheat cultures; this represents a significant yield improvement from a previous method, offers more materials to study the modes of its action, and facilitates the elucidation of the apicidin biosynthesis pathway. Apicidin and apicidin $D_2$ showed phytotoxicity on both seedlings and 2-week-old plants of diverse species, and weeds were more sensitive to apicidins than vegetables

• Research in Plant Disease
• /
• v.25 no.2
• /
• pp.94-97
• /
• 2019

In February 2019, a damping-off disease occurred at the seedling stage of paprika in a commercial nursery located in Cheorwon, Korea. A species of Fusarium was isolated from the diseased plant and it was identified as Fusarium oxysporum based on morphological characteristics and nucleotide sequence data of translation elongation factor $1-{\alpha}$ and the largest subunit of RNA polymerase. The isolate obtained was revealed to be pathogenic to the host plant through pathogenicity tests, and the reisolation of the pathogen confirmed Koch's postulates. This is the first report of damping-off caused by Fusarium oxysporum on paprika in Korea.