• Mycobiology
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• v.48 no.3
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• pp.195-203
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• 2020

Marine yeasts have tremendous potential in industrial applications but have received less attention than terrestrial yeasts and marine filamentous fungi. In this study, we have screened marine yeasts for amylolytic activity and identified an amylase-producing strain PH-Gra1 isolated from sea algae. PH-Gra1 formed as a coral-red colony on yeast-peptone-dextrose (YPD) agar; the maximum radial growth was observed at 22 ℃, pH 6.5 without addition of NaCl to the media. Based on the morphology and phylogenetic analyses derived from sequences of internal transcribed spacer (ITS) and a D1/D2 domain of large subunit of ribosomal DNA, PH-Gra1 was designated Sporidiobolus pararoseus. S. pararoseus is frequently isolated from marine environments and known to produce lipids, carotenoids, and several enzymes. However, its amylolytic activity, particularly the optimum conditions for enzyme activity and stability, has not been previously characterized in detail. The extracellular crude enzyme of PH-Gra1 displayed its maximum amylolytic activity at 55 ℃, pH 6.5, and 0%-3.0% (w/v) NaCl under the tested conditions, and the activity increased with time over the 180-min incubation period. In addition, the crude enzyme hydrolyzed potato starch more actively than corn and wheat starch, and was stable at temperatures ranging from 15 ℃ to 45 ℃ for 2 h. This report provides a basis for additional studies of marine yeasts that will facilitate industrial applications.

• The Korean Journal of Mycology
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• v.48 no.3
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• pp.355-367
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• 2020

One hundred representative species of fungi in Korea were selected and their Korean names were proposed to increase interest in fungi among Korean people. This task was performed under the supervision of the Committee of Mycological Terms, under the Korean Society of Mycology. First, the committee established the criteria for selecting 100 representative species of fungi in Korea and then selected the candidate fungal species accordingly. To ensure the uniformity and stability of Korean fungal names, the principle of naming fungi in Korean was established, and the candidate Korean fungal names were presented accordingly. Finally, the candidate Korean fungal names were posted online to collect opinions of the members of the Korean Society of Mycology. The candidate Korean names of the plant pathogenic fungi and mushrooms were reviewed by the Korean Society of Plant Pathology and the Korean Society of Mushroom Science, respectively. After their opinions were considered, the Korean names for 100 representative fungi in Korea were finally determined. The 100 fungi comprised 41 common molds and yeasts, 28 plant pathogenic fungi, and 31 mushrooms.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.17 no.2
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• pp.59-75
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• 2012

The species composition of plankton is essential to understand the material and energy cycling within marine ecosystem. It also provides the useful information for understanding the properties of marine environments due to its sensitivity to the physicochemical characteristics and variability of water masses. In this study we adopted metagenomics to evaluate eukaryotic plankton species diversity from coastal waters off Busan. Characteristics of water masses at sampling sites is expected to be very complex due to the mixing of various water masses; Nakdong River runoff, Changjiang diluted water (CDW), South Sea coastal water, and Tsushima warm current. 18S rDNA clone libraries were constructed from surface waters at the three sites off Busan. Clone libraries revealed 94 unique phylotypes from 370 clones; Dinophyceae(42 phylotypes), Ciliophora(15 phylotypes), Bacillariophyta(7 phylotypes), Chlorophyta(2 phylotypes), Haptophyceae(1 phylotype), Metazoa(Arthropoda( 17 phylotypes), Chaetognatha(1 phylotypes), Cnidaria(2 phylotypes), Chordata(1 phylotype)), Rhizaria (Acantharea(2 phylotypes), Polycystinea(1 phylotype)), Telonemida(1 phylotype), Fungi(2 phylotypes). The difference in species diversity at the closely located three sites off Busan may be attributed to the various physicochemical properties of water masses at these sites by the mixture of water masses of various origins. Metagenomic study of species composition may provide useful information for understanding marine ecosystem of coastal waters with various physicochemical properties in the near feature.

• Natural Product Sciences
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• v.13 no.1
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• pp.90-96
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• 2007

Bioactivity guided fractionation of the cultured filtrates of Aspergillus versicolor, which was derived from a marine sponge Petrosia sp., yielded three polyketides: decumbenones A (1),B (2), and versiol (3). These compounds were identified on the basis of 1D and 2D NMR spectroscopic and MS analysis. The absolute configuration was defined by the modified Mosher's method. The isolated compounds were tested for cytotoxicity against a panel of five human solid tumor cell lines and antibacterial activity against twenty clinically isolated methicillin-resistant strains. This is the first report on the isolation of these compounds from a marine source.

• Research in Plant Disease
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• v.30 no.1
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• pp.20-25
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• 2024

A fungus strain Stereostratum corticioides PKVL1, belonging to the family Pucciniaceae that causes rust in plants, was discovered on the sheath of the bamboo Pseudosasa japonica leading to the death of the infected bamboo in the following year. Microscopic observation of the yellow fungal mass revealed teliospores with an oval, one-septate (two-celled) structure. The average length and width of teliospores were 31.83±3.57 ㎛ and 20.74±1.72 ㎛, respectively. The large-subunit ribosomal RNA gene was amplified using the LR0R and LR7 primers, showing that the strain PKVL1 had a similarity of 99.34% to previously reported S. corticioides. In particular, the two Stereostratum strains form a separate cluster among the fungi in the family Pucciniaceae. This is the first report in the Republic of Korea of fungal rust occurring on the culm of bamboo rather than on the leaves.

• ALGAE
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• v.26 no.4
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• pp.343-350
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• 2011

Fermentation and enzyme-assisted extraction (EAE) improve nutritional and functional properties of foods by increasing the extraction of active compounds, ingestion rates, and body absorption. In this study, we investigated whether applying the EAE process improves the extraction and isolation efficiency of a polysaccharide from fermented Ecklonia cava (FE), which inhibited NO production in lipopolysaccharide (LPS)-activated RAW 264.7 cells. The results showed that the FE using the fungi Candida utilis and two different bacteria, namely Lactobacillus brevis and Saccharomyces cerevisiae increased protein and carbohydrate contents in comparison with those in non-fermented E. cava (NE). Aqueous extracts of fermented E. cava increased extraction yields and carbohydrate content, compared with the aqueous extract of NE. In addition, treating LPS-stimulated RAW 264.7 cells with aqueous extracts resulted in reduced NO production compared to that in LPS-treated cells. Ten EAEs of L. brevis-fermented E. cava (LFE) improved NO inhibitory effects in LPS-activated RAW 264.7 cells and the Viscozyme extract (VLFE) from the resulting extracts showed the highest NO inhibitory effect. We found that the >30 kDa fraction of VLFE led to markedly high inhibition of LPS-induced NO production as compared to that in the <30 kDa fraction. The crude polysaccharide isolated from >30 kDa fraction (VLFEP) consisted of fucose and markedly decreased NO production induced by LPS stimulation. VLFEP could be useful as an anti-inflammatory agent to suppress macrophage activation.

• Mycobiology
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• v.51 no.4
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• pp.246-255
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• 2023

Genus Penicillium comprising the most important and extensively studied fungi has been well-known as a rich source of secondary metabolites. Our study aimed to analyze and investigate biological activities, including in vitro anti-cancer, anti-inflammatory and anti-diabetic properties, of metabolites from a marine-derived fungus belonging to P. levitum. The chemical compounds in the culture broth of P. levitum strain N33.2 were extracted with ethyl acetate. Followingly, chemical analysis of the extract leaded to the isolation of three ergostane-type steroid components, namely cerevisterol (1), ergosterol peroxide (2), and (3β,5α,22E)-ergosta-6,8(14),22-triene-3,5-diol (3). Among these, (3) was the most potent cytotoxic against human cancer cell lines Hep-G2, A549 and MCF-7 with IC₅₀ values of 2.89, 18.51, and 16.47 ㎍/mL, respectively, while the compound (1) showed no significant effect against tested cancer cells. Anti-inflammatory properties of purified compounds were evaluated based on NO-production in LPS-induced murine RAW264.7 macrophages. As a result, tested compounds performed diverse inhibitory effects on NO production by the macrophages, with the most significant inhibition rate of 81.37±1.35% at 25 ㎍/mL by the compound (2). Interestingly, compounds (2) and (3) exhibited inhibitory activities against pancreatic lipase and α-glucosidase enzymes in vitro assays. Our study brought out new data concerning the chemical properties and biological activities of isolated steroids from a P. levitum fungus.

• Korean Journal of Environmental Agriculture
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• v.27 no.1
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• pp.80-85
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• 2008

This study was carried out to assess the antidermatophytic potential of the ethyl acetate(EtOAc) extract of the marine isolate of Aspergillus sp.. The fungus was isolated by serial dilution, and was identified Aspergillus sp.. The EtOAc extract of the fungus was examined to evaluate the antidermatophytic efficacy against the fungal pathogens infecting human skin using the disc diffusion and MIC(minimum inhibitory concentration) determination methods. The EtOAc extract($5{\mu}l\;disc^{-1}$) was considered to have the antidermatophytic activity based on the inhibition percentage of the mycelial growth of the fungi tested such as Trichophyton mentagrophytes KCTC 6085, Microsporum canis KCTC 6591, Microsporum canis KCTC 6348, Trichophyton rubrum KCTC 6352, Microsporum canis KCTC 6349 and Trichophyton mentagrophytes KCTC 6316. The percentage of the inhibition ranged from 54% to 81, and the MIC obtained was 62.5, 62.5, 250, 125, 125, and $125{\mu}g\;ml^{-1}$, respectively. The extract had a strong detrimental effect on the spore germination of the tested skin infectious pathogens. These findings strongly support the role of the ethyl acetate extract as a potential antidermatophytic agent.

• Journal of Microbiology and Biotechnology
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• v.25 no.7
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• pp.1101-1107
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• 2015

The role of CRE1 in a thermophilic fungus, Myceliophthora thermophila ATCC42464, was studied using RNA interference. In the cre1-silenced strain C88, the filter paper hydrolyzing activity and β-1,4-endoglucanase activity were 3.76-, and 1.31-fold higher, respectively, than those in the parental strain when the strains were cultured in inducing medium for 6 days. The activities of β-1,4-exoglucanase and cellobiase were 2.64-, and 5.59-fold higher, respectively, than those in the parental strain when the strains were cultured for 5 days. Quantitative reverse-transcription polymerase chain reaction showed that the gene expression of egl3, cbh1, and cbh2 was significantly increased in transformant C88 compared with the wild-type strain. Therefore, our findings suggest the feasibility of improving cellulase production by modifying the regulator expression, and an attractive approach to increasing the total cellulase productivity in thermophilic fungi.

• Mycobiology
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• v.49 no.3
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• pp.235-248
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• 2021

This study aimed to understand whether the geo-ecological segregation of native plant species affects the root-associated fungal community. Rhizoplane (RP) and rhizosphere (RS) fungal microbiota of Sedum takesimense native to three geographically segregated coastal regions (volcanic ocean islands) were analyzed using culture-independent methods: 568,507 quality sequences, 1399 operational taxonomic units, five phyla, and 181 genera were obtained. Across all regions, significant differences in the phyla distribution and ratio were confirmed. The Chao's richness value was greater for RS than for RP, and this variance coincided with the number of genera. In contrast, the dominance of specific genera in the RS (Simpson value) was lower than the RP at all sites. The taxonomic identity of most fungal species (95%) closely interacting with the common host plant was different. Meanwhile, a considerable number of RP only residing fungal genera were thought to have close interdependency on their host halophyte. Among these, Metarhizium was the sole genus common to all sites. These suggest that the relationship between potential symbiotic fungi and their host halophyte species evolved with a regional dependency, in the same halophyte species, and of the same natural habitat (volcanic islands); further, the fungal community differenced in distinct geographical regions. Importantly, geographical segregation should be accounted for in national culture collections, based on taxonomical uniqueness.