• The Korean Journal of Mycology
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• v.48 no.4
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• pp.397-405
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• 2020

Beech mushroom (Hypsizygus marmoreus) is one of the most popular mushrooms in Japan, China, and Korea because of its delicious taste, nutritious value, and unique crunchy texture. In 2018-2019, unusual signs on the mushroom were observed in mushroom farms in Gyeongnam Province. The main signs were the inhibition of mycelial growth and primordial formation on the surface of mushroom media. When green mold caused contamination at early stage, the rate of pinhead formation by the mushroom greatly decreased to 46.5-71.5%. Conidia of the causal green mold were ellipsoidal, dark green, and measured 2.0-3.1㎛ long. The optimum temperature for mycelial growth of the green mold was 25℃. The phylogenetic tree obtained from the internal transcribed spacer (ITS) rDNA sequences showed that the isolated green mold corresponded to Penicillium brevicompactum (100.0%). This is the first report of green mold contamination caused by P. brevicompactum on H. marmoreus.

• Parasites, Hosts and Diseases
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• v.58 no.6
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• pp.653-660
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• 2020

Spirometra tapeworms (Cestoda: Diphyllobothriidae) collected from carnivorous mammals in Tanzania were identified by the DNA sequence analysis of the mitochondrial cytochrome c oxidase subunit 1 (cox1) and internal transcribed spacer 1 (ITS1), and by morphological characteristics. A total of 15 adult worms were collected from stool samples and carcasses of Panthera leo, Panthera pardus, and Crocuta crocuta in the Serengeti and Selous ecosystems of Tanzania. Three Spirometra species: S. theileri, S. ranarum and S. erinaceieuropaei were identified based on morphological features. Partial cox1 sequences (400 bp) of 10 specimens were revealed. Eight specimens showed 99.5% similarity with Spirometra theileri (MK955901), 1 specimen showed 99.5% similarity with the Korean S. erinaceieuropaei and 1 specimen had 99.5% similarity with Myanmar S. ranarum. Sequence homology estimates for the ITS1 region of S. theileri were 89.8% with S. erinaceieuropaei, 82.5% with S. decipiens, and 78.3% with S. ranarum; and 94.4% homology was observed between S. decipiens and S. ranarum. Phylogenetic analyses were performed with 4 species of Spirometra and 2 species of Dibothriocephalus (=Diphyllobothrium). By both ML and BI methods, cox1 and ITS1 gave well supported, congruent trees topology of S. erinaceieuropaei and S. theileri with S. decipiens and S. ranarum forming a clade. The Dibothriocephalus species were sisters of each other and collectively forming successive outgroups. Our findings confirmed that 3 Spirometra species (S. theileri, S. ranarum, and S. erinaceieuropaei) are distributed in the Serengeti and Selous ecosystems of Tanzania.

• Journal of Microbiology and Biotechnology
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• v.33 no.8
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• pp.1023-1029
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• 2023

Biosurfactants reduce surface and interfacial tension due to their amphiphilic properties and are an eco-friendly alternative for chemical surfactants. In this study, a new yeast strain JAF-11 that produces a biosurfactant was selected using drop collapse method, and the properties of the extracts were investigated. The nucleotide sequences of the strain were compared with closely related strains and identified based on the D1/D2 domain of the large subunit ribosomal DNA (LSU) and internal transcribed spacer (ITS) regions. Neodothiora populina CPC 39399^T, the closest species with strain JAF-11, showed a sequence similarity of 97.75% for LSU and 94.27% for ITS, respectively. The result suggests that the strain JAF-11 represents a distinct species that cannot be assigned to any existing genus or species in the family Dothideaceae. Strain JAF-11 produced a biosurfactant reducing the surface tension of water from 72 mN/m to 34.5 mN/m on the sixth day of culture and the result of measuring the critical micelle concentration (CMC) by extracting the crude biosurfactant was found to be 24 mg/l. The molecular weight 502 of the purified biosurfactant was confirmed by measuring the fast atom bombardment mass spectrum. The chemical structure was analyzed by measuring ¹H nuclear magnetic resonance (NMR), ¹³C NMR, and two-dimensional NMRs of the compound. The molecular formula was C₂₆H₄₆O₉, and it was composed of one octanoyl group and two hexanoyl groups to myo-inositol moiety. The new biosurfactant is the first report of a compound produced by a new yeast strain, JAF-11.

• Food Science and Preservation
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• v.30 no.3
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• pp.483-491
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• 2023

This study aimed to compare the bioactive compounds in Centella asiatica (C. asiatica) cultivated in a smart farm and a field and their effects on human keratinocyte cells. C. asiatica was collected in Jeju-do, Korea, and cultured in a smart farm and a field. The main bioactive compounds in the two differentially cultured C. asiatica were identified, and their activation in keratinocytes were assessed. Amplification and sequencing of the internal transcribed spacer (ITS) DNA in the nucleus and psbA-H DNA in the chloroplast were performed for species analysis. A comparison of DNA of plants reported in the NCBI GenBank was performed. The ITS DNA and psbA-H DNA sequences of C. asiatica cultivated in a smart farm and a field were consistent with No. MH768338.1 and No. JQ425422.1, respectively. Analysis of the triterpenes was performed using high performance liquid chromatography (HPLC) and as a result, C. asiatica cultured in a smart farm had more triterpenes than those cultured in a field. The effects of C. asiatica grown in a smart farm on cell proliferation and scratch recovery in HaCaT cells were greater than those grown in a field. These results suggest that C. asiatica cultivated in a smart farm can be effectively utilized as a health functional food.

• The Korean Journal of Mycology
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• v.24 no.2 s.77
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• pp.155-165
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• 1996

This study was carried out to identify the phylogenetic relationship among several isolates of Pleurotus species by comparing ITS II region of ribosomal DNA(rDNA) repeat unit. Two primers from ribosomal DNA sequences were chosen to amplify the specific internal transcribed spacer (ITS) II region of Pleurotus spp. The exact ITS II region with an unique band from six species of Pleurotus genus could be amplified using the two primers taken from at the 3'-end of 5.8S rDNA and 5'-end of 28S rDNA. Six representative species of the Pleurotus genus were easily characterized according to the length differences of ITS II region. Furthermore, within P. ostreatus species, different sizes of ITS II region could be observed in the isolates of ASI 2025 and ASI 2095 although they were classified as P. ostreatus by the conventional observation. The nucleotide sequence analyses of PCR-amplified ITS II region indicated that the isolates ASI 2025 and ASI 2095 were different from other Pleurotus spp. When the nucleotide sequences of six Pleurotus species were compared, three typical ITS II regions were highly variable especially at both ends of this region. The phylogenetic tree obtained by the Neighbor program of Felsenstein PHYLIP package with all the nucleotide sequence of Pleurotus spp. indicated that P. ostreatus, P. florida, P. sajor-caju and P. eryngii were closely related to one phylogenetic branch and P. cystidious was related to other branch with P. cornucopiae. The isolates ASI 2025 and 2038, however, were not closely related to any other Pleurotus spp. and formed their own individual branches.

• Korean Journal of Breeding Science
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• v.41 no.4
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• pp.420-428
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• 2009

In this study, the variation of 20 Pinus thunbergii isolates of F. circinatum from 2 damaged sites in Jeju-Island were compared with a known Fusarium circinatum using molecular biological techniques. Two- and four-year-old seedlings of Pinus rigida${\times}$Pinus x rigitaeda and two-, three- and six-year-old seedlings of P. thunbergii were inoculated with one of the most virulent isolates, FT-7, to determine differences in susceptibility. In site 1 (FT), 13 isolates of F. circinatum were isolated from 14 individuals and in site 2 (FS), 7 isolates of F. circinatum were isolated from 9 individuals. No difference was found in the sequences of the internal transcribed spacer (ITS) region of the ribosomal RNA genes in the FS and FT isolates, and also even in the known isolate of F. circinatum, FE 1-1. However, the ITS sequences of the FS and FT isolates differed from those of a fungus, Botrytis cinerea. Two-year-old seedlings of P. rigida${\times}$P. x rigitaeda showed higher susceptibility (93.3% of mortality) than four-year-old ones. Three-year-old seedlings of P. thunbergii showed the highest susceptibility (66.7% of mortality) compared to those at other ages in the same species. We found a positive correlation between basal diameter and lesion length in the seedlings of P. rigida${\times}$P. x rigitaeda ($R^2=0.66$) and P. thunbergii (p < 0.0001), respectively. There were significant differences in susceptibility by the age of seedlings in each of P. rigida${\times}$P. x rigitaeda (p < 0.0001) and P. thunbergii (p < 0.0001) based on lesion length.

• Horticultural Science & Technology
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• v.33 no.3
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• pp.409-419
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• 2015

This study was conducted to establish an efficient screening method for watermelon plants resistant to Fusarium wilt (FW), which is caused by Fusarium oxysporum f. sp. niveum (Fon). An HA isolate was prepared from a wilted watermelon plant in Haman-gun and identified as F. oxysporum f. sp. niveum based on morphological characteristics, molecular analyses of ITS (internal transcribed spacer) and TEF (translation elongation factor $1{\alpha}$) sequences, and host specificity on cucurbits including watermelon, melon, oriental melon, and cucumber. The assay for disease response of watermelon differentials indicated that the HA isolate was race 0. Among seven liquid media tested, the highest amount of Fon spores was produced from V8-juice broth, which was selected as a medium for mass production of Fon. The disease assay for 21 watermelon and 11 watermelon-rootstock cultivars demonstrated that 20 watermelon cultivars except for 'Soknoranggul' were susceptible; 'Soknoranggul' was moderately resistant. All the tested rootstock cultivars were highly resistant to the HA isolate. The evaluation of disease development depending on various conditions suggested that an efficient screening method for FW resistance in watermelon plants is to dip the roots of 10-day-old seedlings in spore suspension of $1.0{\times}10^5-1.0{\times}10^6conidia{\cdot}mL^{-1}$ for 30 min., to transplant the seedlings to plastic pots with a fertilized soil, and then to cultivate the plants at $25^{\circ}C$ for 3 weeks.

• Horticultural Science & Technology
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• v.34 no.2
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• pp.305-313
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• 2016

Brassica juncea (2n = 4x = 36, AABB genome, 1,068 Mb) is a U's triangle species and an amphidiploid derivative of B. rapa and B. nigra. Fifteen varieties were used to study the ITS (internal transcribed spacer) regions of ribosomal DNA and MITEs (miniature inverted-repeat transposable elements) with a view of developing specific molecular markers. ITSs and MITEs are an excellent resource for developing DNA markers for genomics and evolutionary studies because most of them are stably inherited and present in high copy numbers. The ITS (ITS1 and ITS2) sequence was compared with the consensus sequence of B. rapa and B. nigra. Variation in ITS1 created two separate groups among 15 varieties, with 10 varieties in one group and 5 in the other. Phylogenetic analysis revealed two major clusters for those 10 and 5 varieties. Among the 160 different MITE primers used to evaluate the selected 15 varieties of B. juncea, 70 were related to the Stowaway, 79 to the Tourist, 6 to the hAT, and 5 to the Mutator super-families of MITEs. Of 160 markers examined, 32 were found to be polymorphic when fifteen different varieties of B. juncea were evaluated. The variety 'Blackgat' was different from the other mustard varieties with respect to both phenotype and genotype. The diversity of 47 additional accessions could be verified using eight selected molecular markers derived from MITE family sequences. The polymorphic markers identified in this study can be used for varietal classification, variety protection, and other breeding purposes.