• Journal of Microbiology and Biotechnology
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• 제31권3호
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• pp.408-418
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• 2021

The diversity and plant growth-promoting ability of fungal endophytes that are associated with five halophytic plant species (Phragmites australis, Suaeda australis, Limonium tetragonum, Suaeda glauca Bunge, and Suaeda maritima) growing in the Buan salt marsh on the west coast of South Korea have been explored. About 188 fungal strains were isolated from these plant samples' roots and were then studied with the use of the internal transcribed spacer (ITS) region (ITS1-5.8S-ITS2). The endophytic fungal strains belonged to 33 genera. Alternaria (18%) and Fusarium (12.8%), of the classes Dothideomycetes and Sordariomycetes, were most rampant in the coastal salt marsh plants. There was a higher diversity in fungal endophytes that are isolated from S. glauca Bunge than in isolates from other coastal salt marsh plants. Plant growth-promoting experiments with the use of Waito-C rice seedlings show that some of the fungal strains could encourage a more efficient growth than others. Furthermore, gibberellins (GAs) GA1, GA3, and GA9 were seen in the Sa-1-4-3 isolate (Acrostalagmus luteoalbus) culture filtrate with a gas chromatography/mass spectrometry.

• Journal of Microbiology and Biotechnology
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• 제22권11호
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• pp.1549-1556
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• 2012

Endophytic fungi were isolated from roots of six halophytes in Suncheon Bay. The endophytic fungi of 35 species isolated from halophytes were identified by internal transcribed spacer (ITS) containing the ITS1, 5.8s, and ITS2 regions. All fungal strains were analyzed to diversity at the genus level. Fungal culture filtrates (FCF) of endophytic fungi were treated to Waito-c rice (WR) seedling for plant growth-promoting verification. It was confirmed that fungal strain Sj-2-2 provided plant growth promotion (PGP) to WR seedling. Then, PGP of Suaeda japonica was confirmed by treating culture filtrate of Sj-2-2. As a result, it was verified that culture filtrate of Sj-2-2 had more advanced PGP than positive control when treated to S. japonica. The secondary metabolites involved in culture filtrate of Sj-2-2 were identified by HPLC and GC-MS SIM analysis. The presence of physiologically bioactive gibberellins (GAs) and other inactive GAs in culture filtrate of Sj-2-2 was detected. The molecular analysis of sequences of Sj-2-2 showed the similarity to Penicillium sp. of 99% homology. The PGP of Sj-2-2 as well as symbiosis between endophytic fungi and halophytes growing naturally in salt marsh was confirmed. Sj-2-2 was identified as a new fungal strain producing GAs by molecular analysis of sequences. Consequently, the Sj-2-2 fungal strain was named as Penicillium sp. Sj-2-2. In this study, the diversity of endophytic fungi isolated from roots of halophytes in salt marsh and the PGP of a new gibberellin-producing fungal strain were confirmed.

• Journal of Microbiology and Biotechnology
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• 제30권11호
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• pp.1680-1687
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• 2020

Fungal endophytes are symbiotic microorganisms that are often found in asymptomatic plants. This study describes the genetic diversity of the fungal endophytes isolated from the roots of plants sampled from the west coast of Korea. Five halophytic plant species, Limonium tetragonum, Suaeda australis, Suaeda maritima, Suaeda glauca Bunge, and Phragmites australis, were collected from a salt marsh in Gochang and used to isolate and identify culturable, root-associated endophytic fungi. The fungal internal transcribed spacer (ITS) region ITS1-5.8S-ITS2 was used as the DNA barcode for the classification of these specimens. In total, 156 isolates of the fungal strains were identified and categorized into 23 genera and two phyla (Ascomycota and Basidiomycota), with Dothideomycetes and Sordariomycetes as the predominant classes. The genus Alternaria accounted for the largest number of strains, followed by Cladosporium and Fusarium. The highest diversity index was obtained from the endophytic fungal group associated with the plant P. australis. Waito-C rice seedlings were treated with the fungal culture filtrates to analyze their plant growth-promoting capacity. A bioassay of the Sm-3-7-5 fungal strain isolated from S. maritima confirmed that it had the highest plant growth-promoting capacity. Molecular identification of the Sm-3-7-5 strain revealed that it belongs to Alternaria alternata and is a producer of gibberellins. These findings provided a fundamental basis for understanding the symbiotic interactions between plants and fungi.

• Mycobiology
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• 제42권2호
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• pp.100-108
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• 2014

Twelve plant species were collected from the east coast of Korea to identify culturable endophytes present in their roots. The fungal internal transcribe spacer (ITS) region (ITS1-5.8SrRNA-ITS2) was used as a DNA barcode for identification of fungi. A total of 194 fungal strains were identified and categorized into 31 genera. The genus Penicillium accounted for the largest number of strains, followed by the genus Aspergillus. Furthermore, using 5 statistical methods, the diversity indices of the fungi were calculated at the genus level. After comprehensive evaluation, the endophytic fungal group from Phragmites australis ranked highest in diversity analyses. Several strains responsible for plant growth and survival (Penicillium citrinum, P. funiculosum, P. janthinellum, P. restrictum, and P. simplicissimum), were also identified. This study provides basic data on the sheds light on the symbiotic relationship between coastal plants and fungi.

• Journal of Ginseng Research
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• 제36권1호
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• pp.107-113
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• 2012

In order to investigate the diversity of endophytes, fungal endophytes in Panax ginseng Meyer cultivated in Korea were isolated and identified using internal transcribed spacer (ITS) sequences of ribosomal DNA. Three cultivars of 3-year-old ginseng roots (Chunpoong, Yunpoong, and Gumpoong) were used to isolate fungal endophytes. Surface sterilized ginseng roots were placed on potato dextrose agar plates supplemented with ampicilin and streptomycin to inhibit bacterial growth. Overall, 38 fungal endophytes were isolated from 12 ginseng roots. According to the sequence analysis of the ITS1-5.8S-ITS2, 38 fungal isolates were classified into 4 different fungal species, which were Phoma radicina, Fusarium oxysporum, Setophoma terrestris and Ascomycota sp. 2-RNK. The most dominant fungal endophyte was P. radicina in 3 cultivars. The percentage of dominant endophytes of P. radicina was 65.8%. The percentage of colonization frequency of P. radicina was 80%, 52.9%, and 75% in Chunpoong, Yunpoong, and Gumpoong, respectively. The second most dominant fungal endophyte was F. oxysporum. The diversity of the fungal endophytes was low and no ginseng cultivar specificity among endophytes was detected in this study. The identified endophytes can be potential fungi for the production of bioactive compounds and control against ginseng pathogens.

• The Plant Pathology Journal
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• 제29권4호
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• pp.435-439
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• 2013

Rice blast fungus, Magnaporthe oryzae, inflicts serious damage to global rice production. Due to high variability of this fungal pathogen, resistance of newly-released rice cultivars is easily broken down. To understand the population structure of M. oryzae, we analyzed the genetic diversity of the Korean population using multilocus microsatellite typing. Eleven microsatellite markers were applied to the population of 190 rice isolates which had been collected in Korea for two decades since the 1980's. Average values of gene diversity and allele frequency were 0.412 and 6.5, respectively. Comparative analysis of the digitized allele information revealed that the Korean population exhibited a similar level of allele diversity to the integrated diversity of the world populations, suggesting a particularly high diversity of the Korean population. Therefore, these microsatellite markers and the comprehensive collection of field isolates will be useful genetic resources to identify the genetic diversity of M. oryzae population.

• 한국균학회지
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• 제48권3호
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• pp.251-271
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• 2020

Diversity and community composition of bulb-associated fungi of Fritillaria Cirrhosae Bulbus source plants, which are used in traditional chinese medicine, in the eastern Himalaya-Hengduan Mountains, southwestern China, were estimated based on the internal transcribed spacer rDNA sequence analysis, using host plant species, geographic area, and plant phenology as variables. A total of 1,486 fungal sequences assigned to 251 operational taxonomical units (OTUs) were obtained from the bulbs. Fungal OTUs comprised 96.41% Ascomycotina, 3.52% Basidiomycotina, and 0.07% Zygomycotina. Sordariomycetes, Hypocreales, and Nectriaceae were the most frequent fungal lineages at each taxonomic rank. Fusarium, Ilyonectria, Tetracladium, Leptodontidium, and Tomentella were the top OTU-rich genera. Fusarium sp. 03, Ilyonectria rufa, Fusarium sp. 08, Ilyonectria sp. 03, and Leptodontidium orchidicola 03 represented the most frequent OTUs. Fusarium spp. were the most frequent general taxa. The distribution of fungal community exhibited preferences for host plant species, geographic area, and plant phenology. These findings are the foundation of our research on culturing and active metabolites of bulb-associated fungi of Fritillaria Cirrhosae Bulbus source plants.

• Journal of Microbiology and Biotechnology
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• 제29권3호
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• pp.441-453
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• 2019

Organic farming is considered an effective form of sustainable agricultural management. However, understanding of soil microbial diversity and composition under long-term organic and conventional farming is still limited and controversial. In this study, the Illumina MiSeq platform was applied to investigate the responses of soil bacterial and fungal diversity and compositions to organic farming (OF) and improved conventional farming (CF, applied straw retention) in the rice-wheat rotation system. The results highlighted that the alpha diversity of microbial communities did not differ significantly, except for higher bacterial diversity under OF. However, there were significant differences in the compositions of the soil bacterial and fungal communities between organic and conventional farming. Under our experimental conditions, through the ecological functional analysis of significant different or unique bacterial and fungal taxonomic members at the phyla and genus level, OF enhanced nitrogen, sulfur, phosphorus and carbon dynamic cycling in soil with the presence of Nodosilinea, Nitrospira, LCP-6, HB118, Lyngbya, GOUTA19, Mesorhizobium, Sandaracinobacter, Syntrophobacter and Sphingosinicella, and has the potential to strengthen soil metabolic ability with Novosphingobium. On the other hand, CF increased the intensity of nitrogen cycling with Ardenscatena, KD1-23, Iamia, Nitrosovibrio and Devosia, but enriched several pathogen fungal members, including Coniochaeta, Corallomycetella, Cyclaneusma, Cystostereum, Fistulina, Curvularia and Dissoconium.

• Mycobiology
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• 제49권2호
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• pp.151-160
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• 2021

Despite recent studies, relatively few are known about the diversity of fungal communities in the deep Atlantic Ocean. In this study, we investigated the diversity of fungal communities in 15 different deep-sea sediments from the South Atlantic Ocean with a culture-dependent approach followed by phylogenetic analysis of ITS sequences. A total of 29 fungal strains were isolated from the 15 deep-sea sediments. These strains belong to four fungal genera, including Aspergillus, Cladosporium, Penicillium, and Alternaria. Penicillium, accounting for 44.8% of the total fungal isolates, was a dominant genus. The antiaflatoxigenic activity of these deep-sea fungal isolates was studied. Surprisingly, most of the strains showed moderate to strong antiaflatoxigenic activity. Four isolates, belonging to species of Penicillium polonicum, Penicillium chrysogenum, Aspergillus versicolor, and Cladosporium cladosporioides, could completely inhibit not only the mycelial growth of Aspergillus parasiticus mutant strain NFRI-95, but also the aflatoxin production. To our knowledge, this is the first report to investigate the antiaflatoxigenic activity of culturable deep-sea fungi. Our results provide new insights into the community composition of fungi in the deep South Atlantic Ocean. The high proportion of strains that displayed antiaflatoxigenic activity demonstrates that deep-sea fungi from the Atlantic Ocean are valuable resources for mining bioactive compounds.

• Journal of Microbiology and Biotechnology
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• 제31권11호
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• pp.1526-1532
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• 2021

Suaeda australis, Phragmites australis, Suaeda maritima, Suaeda glauca Bunge, and Limonium tetragonum in the Seocheon salt marsh on the west coast of the Korean Penincula were sampled in order to identify the endophytes inhabiting the roots. A total of 128 endophytic fungal isolates belonging to 31 different genera were identified using the fungal internal transcribed spacer (ITS) regions and the 5.8S ribosomal RNA gene. Fusarium, Paraconiothyrium and Alternaria were the most commonly isolated genera in the plant root samples. Various diversity indicators were used to assess the diversity of the isolated fungi. Pure cultures containing each of the 128 endophytic fungi, respectively, were tested for the plant growth-promoting abilities of the fungus on Waito-C rice germinals. The culture filtrate of the isolate Lt-1-3-3 significantly increased the growth of shoots compared to the shoots treated with the control. Lt-1-3-3 culture filtrate was analyzed and showed the presence of gibberellins (GA₁ 2.487 ng/ml, GA₃ 2.592 ng/ml, GA₉ 3.998, and GA₂₄ 6.191 ng/ml). The culture filtrate from the Lt-1-3-3 fungal isolate produced greater amounts of GA₉ and GA₂₄ than the wild-type Gibberella fujikuroi, a fungus known to produce large amounts of gibberellins. By the molecular analysis, fungal isolate Lt-1-3-3 was identified as Gibberella intermedia, with 100% similarity.