• 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.

• The Korean Journal of Mycology
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• v.37 no.2
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• pp.130-133
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• 2009

The endophytic fungi were isolated from red pine trees (Pinus densiflora) that were distributed in three sites of Chungbuk, Korea. Twenty fungal isolates were isolated from 16 trees and divided into 8 groups by morphological characters. The fungal isolates were identified using the sequences of ITS region of rDNA; Lophodermium complex, Sydowia polyspora, Hymenula sp., Sistotrema brinkmannii, Septoria pini-thunbergii, Earliella sp. Lophodermium spp. were the most frequently found fungal species the across sites and firstly detected from Pinus species in Korea by molecular work.

• Journal of Microbiology and Biotechnology
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• v.15 no.2
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• pp.428-433
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• 2005

A bacteriocin-producing lactic acid bacterium with inhibitory activity against the growth of Lactobacillus plantarum was isolated from kimchi, a traditional Korean fermented vegetable. For the identification of the isolate, its 16S rDNA was sequenced. As a result, the sequence showed $99\%$ homology with those from Lactobacillus paraplantarum, Lb. plantarum, and Lactobacillus pentosus. For further identification of the isolate, the sequence of its 16S/23S rDNA spacer region was determined, and the sequence matched perfectly with that of Lb. paraplantarum. SDS­PAGE fingerprinting of whole-cell proteins of the isolate was almost identical with that of Lb. paraplantarum. The isolation and identification of Lb. paraplantarum suggest that Lb. paraplantarum is one of the lactic acid bacteria involved in kimchi fermentation.

• ALGAE
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• v.38 no.2
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• pp.127-139
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• 2023

Cryptic stages of diverse macroalgae present in natural substrata, "the bank of microscopic forms", were isolated into clonal cultures and identified based on both morphological characteristics and DNA barcoding. Approximately 120 clonal isolates from 308 natural substratum samples were collected from the entire coastline of Kuwait. Amongst these isolates, 77 (64%) were identified through DNA barcoding using the nuclear ribosomal small subunit, RuBisCO spacer (ITS2, tufa, rbcL, psaA, and psbA) and sequencing. Twenty-six isolates (34%) were identified in the division Chlorophyta, 18 (23%) as Phaeophyceae, and 33 (43%) as Rhodophyta. For all DNA sequences in this study, species-level cut off applied was ≥98% homology which depend entirely on the markers used. Three putative new records of Chlorophyta new for the Arabian Gulf were made: Cladophora laetevirens (Dillwyn) Kützing, Ulva torta (Mertens) Trevisan and Ulvella leptochaete (Huber) R. Nielsen, C. J. O'Kelly & B. Wysor in Nielsen, while Cladophora gracilis Kützing and Ulva ohnoi M. Hiraoka & S. Shimada are new records for Kuwait. For Phaeophyceae, Ectocarpus subulatus Kützing and Elachista stellaris Areschoug were new records for the Gulf and Kuwait. In the Rhodophyta, Acrochaetium secundatum (Lyngbye) Nägeli in Nägeli & Cramer, Ceramium affine Setchell & N. L. Gardner, Gelidium pusillum var. pakistanicum Afaq-Husain & Shameel and Dasya caraibica Børgesen are new records for the Gulf and Kuwait, while the red alga Stylonema alsidii (Zanardini) K. Drew is a new record for Kuwait. Several isolates identified corresponded to genera not previously reported in Kuwait and / or the Arabian Gulf, such as Porphyrostromium Trevisan, a new genus from the Bangiales, and two unidentified species for the Planophilaceae Škaloud & Leliaert. The isolates cultivated from substrata enhance understanding of the marine macroalgal diversity in the region and confirmed that the Germling Emergence Method is suitable for determining the actual diversity of a given study area through isolation from cryptic life-history phases.

• Proceedings of the Korean Society of Plant Pathology Conference
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• 2003.10a
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• pp.127.1-127
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• 2003

We describe two new Trichoderma species associated with oyster mushroom in Korea. Trichoderma green mould has been one of the most serious diseases of oyster mushroom in Korea. Of these the predominant species are two unrecorded species. We designed as Trichoderma sp. Korean type 1 (Th K1) and Trichoderma sp. Korean type 2 (Th K2), respectively. Th K1 and Th K2 can be distinguished from previously reported Trichoderma species as well as each other in morphological characteristics including growth rate at 35$^{\circ}C$, colony morphology, conidia shape and branch pattern of phialides. Sequence of the ITS region of rDNA, the protein coding translation elongation factor gene(EF-1${\alpha}$), and RNA polymeraseII (RPB2) not only clearly separated Trichoderma sp. Korean types from their closely related T. harzianum biotype but also distinguished them from each other. Analyses of the EF-1${\alpha}$ and RPB2 sequences were found to be more useful for establishing systematic relationships among Trichoderma isolates than those of the ITS sequence. Based on the results of morphological and molecular characteristics. We propose the two Trichoderma sp. Korean types as the new species

• Mycobiology
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• v.51 no.6
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• pp.379-387
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• 2023

In this study, twenty-five yeast strains were isolated from soil samples collected in the gold mining ore in Gia Lai, Vietnam. Among them, one isolate named GL1^T could highly tolerate Cu²⁺ up to 10 mM, and the isolates could also grow in a wide range of pH (3-7), and temperature (10-40 ℃). Dried biomass of GL1 was able to remove Cu²⁺ effectively up to 90.49% with a maximal biosorption capacity of 18.1 mg/g at pH 6, temperature 30 ℃, and incubation time 60 min. Sequence analysis of rDNA indicated this strain was closely related to Rhodotorula mucilaginosa but with 1.53 and 3.46% nucleotide differences in the D1/D2 domain of the 28S rRNA gene and the ITS1-5.8S rRNA gene-ITS2 region sequence, respectively. Based on phylogenetic tree analysis and the biochemical characteristics, the strain appears to be a novel Rhodotorula species, and the name Rhodotorula aurum sp. nov. is proposed. This study provides us with more information about heavy metal-tolerant yeasts and it may produce a new tool for environmental control and metal recovery operations.

• Mycobiology
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• v.30 no.2
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• pp.82-87
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• 2002

Species of Phellinus were known to harmful fungi causing white pocket rot and severe plant disease such as canker or heartrot in living trees in the West, but some species have been used to traditional medicines in the Orient for a long time. In this study the partial D1-D2 nucleotide sequences of 28S ribosomal DNA from 13 Phellinus strains were determined and compared with the sequences of 21 strains obtained from GenBank database. According to the neighbor-joining(NJ) method comparing the sequence data the phylogenetic tree was constructed. The phylogenetic tree displayed the presence of four groups. Group I includes P. ferreus, P. gilvus and P. johnsonianus, Group II contains P. laevigatus, P. conchatus and P. tremulae, Group III possesses P. linteus, P. weirianus, P. baumii, P. rhabarbarinus and P. igniarius, and Group IV comprises P. pini, P. chrysoloma. P. linteus and P. baumii, which were used mainly in traditional medicine, belong to the same group, but exactly speaking both were split into two different subgroups. To detect P. linteus only, we developed the PCR primer, D12HR. The primer showed the specific amplification of P linteus, which is permitted to medicinal mushroom in the East. The results make a potential to be incorporated in a PCR identification system that could be used for the rapid identification of this species from its related species, P. linteus especially.

• 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.

• Research in Plant Disease
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• v.18 no.2
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• pp.133-138
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• 2012

In November 2009, a powdery mildew on glossy abelia (Abelia ${\times}$ grandiflora) was found in Seogwipo, Jeju Island, Korea. Further survey in the southern part of Korea, e.g., Jeju, Busan, and Tongyeong confirmed occurrence of the disease. White colonies were present on leaves, young stems, and flowers, detracting from their beauty in landscape plantings. Severely infected lesions were discolored to red-purplish. Based on the morphological characteristics and analysis of rDNA, the fungus associated with the symptoms was identified as Erysiphe abeliicola U. Braun & S. Takam. This work provides the morphological feature of its anamorph for the first time, which is characterized by having multi-lobed hyphal appressoria and short foot-cells of conidiophores. Morphological characteristics of mature chasmothecia were consistent with the previous Japanese record of this species. The sequence of internal transcribed spacer region of ribosomal DNA obtained from a Korean sample showed that this species places in the section Microsphaera of the genus Erysiphe in phylogenetic position, corresponding with the classical taxonomy. This is the first report of E. abeliicola and its host plant in Korea. The host plant A. ${\times}$ grandiflora is newly listed in the host range of E. abeliicola.

• The Korean Journal of Mycology
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• v.40 no.2
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• pp.86-92
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• 2012

Halophyte samples, such as Suaeda japonica, Phragmites australis, Limonium tetragonum, Suaeda maritima were collected from Go-chang salt marsh. Thirty-nine endophytic fungal strains were isolated from the roots of halophytes naturally growing in salt marsh. All endophytic fungal strains isolated were analyzed by internal transcribed spacer (ITS) containing ITS1, 5.8 s and ITS2 region. Endophytic fungal strains belong to eight orders, i.e., Eurotiales (36%), Pleosporales (26%), Hypocreales (18%), Incertae sedis (8%), Glomerellales (5%), Sordariales (2%), Xylariales (2%), and Capnodiales (3%). On genus level, they were composed of Alternaria, Aspergillus, Chaetomium, Cladosporium, Colletotrichum, Coniothyrium, Dothideomycete, Fusarium, Gibberella, Macrophoma, Penicillium, Pestalotiopsis, Phaeosphaeria, Phoma, Pleosporales, Pseudozyma, Talaromyces, and Termitomyces. Of them, Penicillium (26%), Fusarium (13%) of Eurotiales and Hypocreales were predominant.