• The Korean Journal of Mycology
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• v.47 no.3
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• pp.209-218
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• 2019

During a survey of fungal diversity in Korea, two fungal strains, KNU17-1 and KNU17-199, were isolated from paddy field soil in Yangpyeong and Sancheong, respectively, in Korea. These fungal isolates were analyzed based on their morphological characteristics and the molecular phylogenetic analysis of the internal transcribed spacer (ITS) rDNA sequences. On the basis of their morphology and phylogeny, KNU17-1 and KNU17-199 isolates were identified as Albifimbria verrucaria and Deconica coprophila, respectively. To the best of our knowledge, A. verrucaria and D. coprophila have not yet been reported in Korea. Thus, this is the first report of these species in Korea.

• The Korean Journal of Mycology
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• v.46 no.4
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• pp.437-446
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• 2018

We investigated the biodiversity of endophytic fungi in Pinus densiflora and Junipreus rigida from Mt. Baekryeonsan and Mt. Johangsan in Korea. In total, 59 isolates were discovered from 26 host plants and identified using sequences from the rDNA internal transcribed spacer (ITS) region. Twenty taxa of endophytic fungi were identified in this study; 62% of isolates belonged to Leotiomycetes, 34% belonged to Sordariomyetes, and 4% belonged to Agaricomycetes. Results confirmed three previously unreported endophytic fungi in Korea: Phanerochaete concrescens, Creosphaeria sassafras, and Scopuloides rimosa. Community analysis showed that the fungal diversity patterns of the samples from Mt Baekryeonsan and Mt. Johangsan are similar to those from previous studies and varied depending upon host and locality.

• Journal of Microbiology and Biotechnology
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• v.32 no.9
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• pp.1134-1145
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• 2022

SCO6993 (606 amino acids) in Streptomyces coelicolor belongs to the large ATP-binding regulators of the LuxR family regulators having one DNA-binding motif. Our previous findings predicted that SCO6993 may suppress the production of pigmented antibiotics, actinorhodin, and undecylprodigiosin, in S. coelicolor, resulting in the characterization of its properties at the molecular level. SCO6993-disruptant, S. coelicolor ΔSCO6993 produced excess pigments in R2YE plates as early as the third day of culture and showed 9.0-fold and 1.8-fold increased production of actinorhodin and undecylprodigiosin in R2YE broth, respectively, compared with that by the wild strain and S. coelicolor ΔSCO6993/SCO6993⁺. Real-time polymerase chain reaction analysis showed that the transcription of actA and actII-ORF4 in the actinorhodin biosynthetic gene cluster and that of redD and redQ in the undecylprodigiosin biosynthetic gene cluster were significantly increased by SCO6993-disruptant. Electrophoretic mobility shift assay and DNase footprinting analysis confirmed that SCO6993 protein could bind only to the promoters of pathway-specific transcriptional activator genes, actII-ORF4 and redD, and a specific palindromic sequence is essential for SCO6993 binding. Moreover, SCO6993 bound to two palindromic sequences on its promoter region. These results indicate that SCO6993 suppresses the expression of other biosynthetic genes in the cluster by repressing the transcription of actII-ORF4 and redD and consequently negatively regulating antibiotic production.

• Journal of the Korean Applied Science and Technology
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• v.40 no.4
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• pp.881-889
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• 2023

The genus Hymenobacter, type genus of the family Hymenobacteraceae and a member of the phylum Bacteroidota includes gram-negative and red-pigmented rods. Those bacteria have been isolated from various environments of the earth. I isolated a red-pigmented, gram-negative rod from a pond in the campus of the Changwon University, Changwon, Kyeongnam and designated this bacterium as strain B2. Strain B2 was further analyzed phylogenetically and biochemically, and concluded as a member of genus Hymenobacter. BLAST search of the 16S rRNA gene sequence of strain B2 showed its homology lower than 98.7% with those sequences of the other bacteria whose 16S rRNA gene sequences have been reported. Fatty acid composition of the strain B2 was analyzed and its major fatty acids are summed feature 3(C_16:1 ω7c and/or C_16:1 ω6c, 22.8%), iso-C_15:0 (16.2%), anteiso-C_15:0(12.9%), C_16:1ω5c(12.4%) and summed feature 4 (iso-C_17:1 I/anteiso-C_17:1)(9.5%) showing significant differences in fatty acid compositions between strain B2 and the other known Hymenobacter species. DNA sequence of 16S rRNA gene of strain B2 was deposited in genbank under accession number OQ318247.

• The Korean Journal of Mycology
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• v.44 no.4
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• pp.350-354
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• 2016

Diverse wild yeast were isolated from freshwaters and soils of Nakdong and Yeongsan rivers in Korea and identified by the comparison of polymerase chain reaction-amplified nucleotide sequences of the internal transcribed spacer region (including the 5.8S rRNA) and D1/D2 regions of 26S rDNA, using BLAST. In total, 15 strains belonging to 9 species were isolated from 25 samples, out of which Aureobasidium pullulans and Cryptococcus bestiolae were dominant. Candida ghanaensis JSF0127 and Meira geulakonigii JSF0130 were identified as unrecorded yeasts, for which their mycological characteristics were investigated. These unrecorded yeasts formed ascospores and grew in yeast extract peptone dextrose medium containing 5% NaCl.

• The Korean Journal of Mycology
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• v.46 no.4
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• pp.459-466
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• 2018

In January 2017, discolored black oat seeds were found in the storage depot of a farmhouse in Jeongeup. Pyrenophora sp. was detected in 45% of the oat seeds surveyed. All Pyrenophora isolates obtained from the seeds were identified as Pyrenophora avenae based on the sequences of internal transcribed spacer (ITS) rDNA regions and glyceraldehyde 3-phosphate dehydrogenase (GPDH) gene and validated by morphological and cultural characterization. A phylogenetic tree constructed using the ITS and GPDH sequences showed that the Korean isolates of P. avenae comprise of four genetically distinct groups. Pathogenicity test validated that the fungus is an infectious agent responsible for discolored black seeds and leaf blotch in oat plants. This is the first study report that P. avenae causes leaf blotch disease of oat in Korea.

• Journal of Microbiology and Biotechnology
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• v.20 no.4
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• pp.651-658
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• 2010

Garcinia is commonly found in Malaysia, but limited information is available regarding endophytic fungi associated with this plant. In this study, 24 endophytic fungi were successfully recovered from different parts of two Garcinia species. Characterization of endophytic fungi was performed based on the conserved internal transcribed spacer (ITS) region sequence analysis and the antimicrobial properties. Results revealed that fruits of the plant appeared to be the highest inhabitation site (38%) as compared with others. Glomerella sp., Guignardia sp., and Phomopsis sp. appeared to be the predominant endophytic fungi group in Garcinia mangostana and Garcinia parvifolia. Phylogenetic relationships of the isolated endophytic fungi were estimated from the sequences of the ITS region. On the other hand, antibacterial screening showed 11 of the isolates possessed positive response towards pathogenic and nonpathogenic bacteria. However, there was no direct association between certain antibacterial properties with the specific genus observed.

• The Plant Pathology Journal
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• v.29 no.1
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• pp.10-16
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• 2013

Hevea brasiliensis is a natural source of rubber and an important plantation tree species in Malaysia. Leaf blight disease caused by Fusicoccum substantially reduces the growth and performance of H. brasiliensis. The aim of this study was to use a combination of both morphological characteristics and molecular data to clarify the taxonomic position of the fungus associated with leaf blight disease. Fusicoccum species were isolated from infected leaves collected from plantations at 3 widely separated locations - Selangor, Perak, and Johor states - in Peninsular Malaysia in 2010. All the isolates were identified according to their conidial patterns and DNA sequences generated from internal transcribed spacers (ITS1 and ITS2), the 5.8S rRNA, and an unknown locus (BotF15) containing microsatellite repeats. Based on taxonomic and sequence data, Neofusicoccum ribis was identified as the main cause of leaf blight disease in H. brasiliensis in commercial plantations in Malaysia. A pathogenicity trial on detached leaves further confirmed that N. ribis causes leaf blight disease. N. ribis is an important leaf pathogen, and its detection in Malaysia has important implications for future planting of H. brasiliensis.

• Journal of Microbiology and Biotechnology
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• v.21 no.7
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• pp.711-718
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• 2011

A highly efficient cellobiohydrolase (CBH)-secreting basidiomycetous fungus, Agaricus arvensis KMJ623, was isolated and identified based on its morphological features and sequence analysis of internal transcribed spacer rDNA. An extracellular CBH was purified to homogeneity from A. arvencis culture supernatant using sequential chromatography. The relative molecular mass of A. arvencis CBH was determined to be 65 kDa by SDSPAGE and 130 kDa by size-exclusion chromatography, indicating that the enzyme is a dimer. A. arvencis CBH showed a catalytic efficiency ($k_{cat}/K_m$) of 31.8 $mM^{-1}\;s^{-1}$ for p-nitrophenyl-${\beta}$-D-cellobioside, the highest level seen for CBH-producing microorganisms. Its internal amino acid sequences showed significant homology with CBHs from glycoside hydrolase family 7. Although CBHs have been purified and characterized from other sources, A. arvencis CBH is distinguished from other CBHs by its high catalytic efficiency.

• Journal of Microbiology and Biotechnology
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• v.5 no.2
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• pp.74-79
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• 1995

Sequence analysis of a DNA region encompassing the site of hybridization to actl, the gene for type II minimal polyketide synthase (PKS) for actinorhodin biosynthesis, from Streptomyces ablus revealed three more complete open reading frames additional to the already found two genes, plausibly encoding ${\beta}-ketoacyl$ synthase/acyl transferase (KS/AT) and chain length determining factor (ClF). The open reading frames (ORFs) were named salA, salD, and salE, from the upstream. In the homology analysis of the deduced amino acid sequences, SalA resembles the Streptomyces glaucescens Tcml, decaketide cyclase, SalD resembles acyl carrier protein in type II PKS, and SalE resembles the Actlll ketoreductase, The whole 4.4 kb of DNA sequence obeys the same conservation pattern as other type II PKSs. Therefore, we suggest that the 4.4 kb DNA from Streptomyces albus encompasses genes encoding enzymes for polyketide biogenesis in the organism and its organization is type II. The exsitence of SaIA, an analogue of the aromatic cyclase, revealed a relatedness of the 4.4 kb DNA with the aromatic PKS.