• Mycobiology
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• v.49 no.1
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• pp.46-53
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• 2021

In a study of the fungal diversity on Ulleung Island in Korea, three novel strains of Penicillium were isolated. Different sites on Ulleung Island were selected for collecting endophytic fungi, and three endophytic fungal strains showed unique morphological characteristics. DNA sequence of the internal transcribed spacer, β-tubulin, calmodulin, and RNA polymerase II second largest subunit regions of the strains were analyzed and they showed unique taxonomic position from the other species of Penicillium section Sclerotiora. The new strains were named Penicillium ulleungdoense sp. nov. As the novel endophytic Penicillium taxa were discovered in a unique environment, the data could be meaningful for understanding the geographical distribution of Ascomycetes on Ulleung Island.

• Journal of Microbiology and Biotechnology
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• v.27 no.1
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• pp.101-111
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• 2017

The task of improving a fungal strain is highly time-consuming due to the requirement of a large number of flasks in order to obtain a library with enough diversity. In addition, fermentations (particularly those for fungal cells) are typically performed in high-volume (100-250 ml) shake-flasks. In this study, for large and rapid screening of itaconic acid (IA) high-yielding mutants of Aspergillus terreus, a miniaturized culture method was developed using 12-well and 24-well microtiter plates (MTPs, working volume = 1-2 ml). These miniaturized MTP fermentations were successful, only when highly filamentous forms were induced in the growth cultures. Under these conditions, loose-pelleted morphologies of optimum sizes (less than 0.5 mm in diameter) were casually induced in the MTP production cultures, which turned out to be the prerequisite for the active IA biosynthesis by the mutated strains in the miniaturized fermentations. Another crucial factor for successful MTP fermentation was to supply an optimal amount of dissolved oxygen into the fermentation broth through increasing the agitation speed (240 rpm) and reducing the working volume (1 ml) of each 24-well microtiter plate. Notably, almost identical fermentation physiologies resulted in the 250 ml shake-flasks, as well as in the 12-well and 24-well MTP cultures conducted under the respective optimum conditions, as expressed in terms of the distribution of IA productivity of each mutant. These results reveal that MTP cultures could be considered as viable alternatives for the labor-intensive shake-flask fermentations even for filamentous fungal cells, leading to the rapid development of IA high-yield mutant strains.

• Journal of Ginseng Research
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• v.36 no.2
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• pp.211-217
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• 2012

Endophytic fungi were isolated from various tissues (root, stem, petiole, leaf, and flower stalk) of 3- and 4-year-old ginseng plants (Panax ginseng Meyer) cultivated in Korea. The isolated endophytic fungi were identified based on the sequence analysis of the internal transcribed spacer (ITS), 1-5.8-ITS 2. A morphological characterization was also conducted using microscopic observations. According to the identification, 127 fungal isolates were assigned to 27 taxa. The genera of Phoma, Alternaria and Colletotrichum were the most frequent isolates, followed by Fusarium, Entrophospora and Xylaria. Although 19 of the 27 taxa were identified at the species level, the remainder were classified at the genus level (6 isolates), phylum level (Ascomycota, 1 isolate), and unknown fungal species (1 isolate). Endophytic fungi of 13 and 19 species were isolated from 3- and 4-year-old ginseng plants, respectively, and Phoma radicina and Fusarium solani were the most frequently isolated species colonizing the tissues of the 3- and 4-year-old ginseng plants, respectively. The colonization frequency (CF%) was dependant on the age and tissue examined: the CFs of the roots and stems in the 3-year-old ginseng were higher than the CF of tissues in the 4-year-old plants. In contrast, higher CFs were observed in the leaves and petioles of 4-year-old plants, and endophytic fungi in the flower stalks were only detected in the 4-year-old plants. In conclusion, we detected diverse endophytic fungi in ginseng plants, which were distributed differently depending on the age and tissue examined.

• The Korean Journal of Mycology
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• v.48 no.4
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• pp.457-473
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• 2020

We investigated the distribution and diversity of fungi in brackish water and soil from the Eulsukdo Island, Geumgang Estuary Bank, Suncheon Bay, Dae-ho Tide Embankment and coastal sand dune in Sinduri and Bu-nam Tide Embankment, Korea. Fungi were isolated from water samples by hand-pumped filtration, and soil samples were collected and diluted. The isolated fungi were incubated in potato dextrose agar at 25℃. A total of 173 fungal strains were isolated from brackish water and identified according to their respective internal transcribed spacer via phylogenetic analysis. The diversity of all fungal strains was analyzed according to diversity indices. The fungal strains belonged to any of 18 taxonomic orders: Pleosporales, Eurotiales, Capnodiales, Hypocreales, Polyporales, Saccharomycetales, Agaricales, Glomerellales, Mucorales, Dothideales, Russulales, Xylariales, Sordariales, Myrmecridiales, Tubeufiales, Onygenales, Cantharellales, and Amphisphaeriales. Cladosporium spp. (20%), Penicillium spp. (19%), and Fusarium sp. (5%) comprised majority of the identified strains. Two species from the fungal isolates were newly identified in Korea: Sarocladium kiliense NNIBRFG3280 and Fusicolla merismoides NNIBRFG23708.

• Korean Journal of Microbiology
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• v.19 no.4
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• pp.154-162
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• 1981

An investigation of the soil microfungal population in the paddy fields of two locations around Seoul was made at four seasons. By the dilution plate method, a total number of propagules of the microfungi pergram of soil was recorded as $10^4$ at the upper layer (0.10cm depth) followed by the middle (10-20cm depth) and the lower layer(20-30 cm depth). The highest number of fungal propagules was $11.0\;{\times}\;10^4$ at the upper layer of the soil collected in autumn. The decreasing tendency of the number of fungal propagules was depend on the increasing depth in paddy fields. Seasonal fluctuation of the fungal population was shown from the highest density of fungal colonies on the plate in autumn season and the lowest one in winter, indicating that the autumn is best season for fungal growth. Generally, the number of the species of Talaromyces in the paddy soils was found to be very high, particularly in autumn, while comparatively low in winter. The highest number of the species of Talaromyces was $6.5\;{\times}\;10^4$ propagules per gram of soil in Yukkog-dong in autumn and the lowest was $0.5\;{\times}\;10^4$ in Shinwon-dong in winter. It is assumed that these fungi grow well also in the warm to the hot seasons.

• Research in Plant Disease
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• v.19 no.3
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• pp.183-187
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• 2013

Barley kernel discoloration (KD) leads to substantial loss in value through downgrading and discounting of malting barley. The objective of this research is to investigate fungal distribution and varieties resistance to KD in Korean two-rowed barley. Several fungal organisms including Alternaria spp., Fusarium spp., Aspergillus spp., Epicoccum spp. and Rhizopus spp. were isolated from Korean two-rowed barley representing KD. The symptoms of KD were brown and black discolorations of the lemma and palea. The most frequently detected fungal species was Alternaria spp. which exhibited 69.1% and 72.2% in 2011 and 2012, respectively. Epicoccum spp., Fusarium spp., and Aspergillus spp. were also detected. Fusarium spp., primary pathogen of barley head blight, were rarely occurred in the 2011 and their occurrence increased to 4.7% in 2012. Twenty cultivars of Korean two-rowed barely were evaluated to KD. The average percentage of KD was 8.0-36.0% in 2011 and 5.2-36.6% in 2012. Two cultivars ('Sacheon 6' and 'Dajinbori') showed KD of 6.2% to 8.8% and determined resistant, however 'Samdobori' and 'Daeyeongbori' demonstrating KD of 22.2-36.6% were highly susceptible. 'Jinyangbori', 'Danwonbori', 'Sinhobori' and 'Kwangmaegbori' showing KD of less than 15% were moderately resistant cultivar.

• Mycobiology
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• v.45 no.3
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• pp.160-171
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• 2017

Larvae of Bradysia agrestis, an insect vector that transports plant pathogens, were sampled from geographically isolated regions in Korea to identify their cutaneous fungal and bacterial flora. Sampled areas were chosen within the distribution range of B. agrestis; each site was more than 91 km apart to ensure geographical segregation. We isolated 76 microbial (fungi and bacteria) strains (site 1, 29; site 2, 29; site 3, 18 strains) that were identified on the basis of morphological differences. Species identification was molecularly confirmed by determination of universal fungal internal transcribed spacer and bacterial 16S rRNA gene sequences in comparison to sequences in the EzTaxon database and the NCBI GenBank database, and their phylogenetic relationships were determined. The fungal isolates belonged to 2 phyla, 5 classes, and 7 genera; bacterial species belonged to 23 genera and 32 species. Microbial diversity differed significantly among the geographical groups with respect to Margalef's richness (3.9, 3.6, and 4.5), Menhinick's index (2.65, 2.46, and 3.30), Simpson's index (0.06, 0.12, and 0.01), and Shannon's index (2.50, 2.17, and 2.58). Although the microbial genera distribution or diversity values clearly varied among geographical groups, common genera were identified in all groups, including the fungal genus Cladosporium, and the bacterial genera Bacillus and Rhodococcus. According to classic principles of co-evolutionary relationship, these genera might have a closer association with their host insect vector B. agrestis than other genera identified. Some cutaneous bacterial genera (e.g., Pseudomonas) displaying weak interdependency with insect vectors may be hazardous to agricultural environments via mechanical transmission via B. agrestis. This study provides comprehensive information regarding the cutaneous microflora of B. agrestis, which can help in the control of such pests for crop management.

• Proceedings of the Korean Society of Fisheries Technology Conference
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• 2002.10a
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• pp.175-176
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• 2002

Rice blast, caused by Pyricularia oryzae (P. oryzae), is generally considered to be the most serious fungal disease of rice by its widespread distribution and destructiveness (Manandhar et al., 1998). The pathogenic fungus directly penetrates into the rice plant from a cellular structure called an appressorium that is formed at the tip of the germ tube. And the fungus can attack any aerial part of the rice plant, including seeds, in which the fungus may overwinter for several years. (omitted)

• The Korean Journal of Mycology
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• v.46 no.4
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• pp.393-403
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• 2018

Bio-aerosols transported by the air have been considered as the major source of dispersal agents that contaminate agricultural products. Unseen fungal spores are known sources of bio-aerosols that harm mushroom and human health during mushroom cultivation. This study was conducted to obtain basic data on the concentration and species distribution of fungi present in the indoor air of oak mushroom cultivation houses in Korea. In 2015 and 2016, we sampled and analyzed indoor airborne fungal spores 21 times from 13 oak mushroom cultivation farms located in six different provinces. The concentration of airborne fungi ranged from $1.30{\times}10^2$ to $1.59{\times}10^4cfu/m^3$. Surprisingly, in 20 sampling cases, the fungal concentration exceeded $500cfu/m^3$, which is recommended as the indoor air quality standard by the Ministry of Environment, Korea. A total of 450 fungi were isolated and identified to belong to 33 genera and 46 species. Among the identified fungi, human pathogens (4 genera and 4 species) and plant pathogens (10 genera and 13 species) were present. In addition, Trichoderma harzianum, Trichoderma atroviride, and Trichoderma longibrachiatum, which are detrimental species that affect mushroom health, were found 17 out of 21 sampling times. Our results provide evidence that indoor air quality should be improved for better management of mushroom cultivation houses.

• Korean Journal of Environmental Biology
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• v.19 no.2
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• pp.153-157
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• 2001

The relationship between SPM (Suspended Particulate Matter) and fungal spore in the air was investigated in Seosan, a rural county of Korea, in spring of 2000. SPM concentrations in the air were $199.8\mu{g}\;m^{-3}$, in the 1st Yellow Sand Period (March, 23-24), $249.4\mu{g}\;m^{-3}$ in the 2nd Yellow Sand Period (April, 7-9) and $98.9\mu{g}\;m^{-3}$ in the Non Yellow Sand Period (May, 12-16), respectively. Although there was somewhat difference in total SPM concentration between the two Yellow Sand Periods, majority of the total SPM were composed of $5\mu{m}$ sized coarse particles over the two periods. However, fine particles sized about $1\mu{m}$and coarse particles sized about $5-6\mu{m}$ ultimately showed peaks, which was within typical bimodal pattern at the graph of SPM size distribution in the Non Yellow Sand Period. Four mold genera grown from airborne fungal spores were finally identified in full-grown colonies at the SPM samples during the Yellow Sand Periods. These genera were Fusarium, Aspergillus, Penicillium and Basipetospora.