• The Korean Journal of Mycology
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• v.40 no.4
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• pp.191-203
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• 2012

Mycelial growth of ectomycorrhizal fungi (27 strains of 8 species) collected from Korean forests was observed on various culture conditions (media, temperature, pHs). After 60 days of incubation, all strains grown on potato dextrose agar (PDA) and modified Melin-Norkran's agar (MMNA), whereas no mycelial growth was observed on malt extract agar (MEA) or sabouraud dextrose agar (SDA) in some strains including Tricholoma matsutake. Mycelial growth on PDA was poor at high temperature ($30^{\circ}C$) than the low temperature ($10^{\circ}C$). The optimal temperature on PDA and pH in potato dextrose broth (PDB) for mycelial growth in most strains were $20-25^{\circ}C$ and pH 4-5, respectively. All strains tested showed the carboxymethyl cellulase (CM-cellulase) activity and the maximal cellullase activity was expressed by the mycelium of T. matsutake (KFRI 1266) on the CMC agar plate with pH 5.0.

• Journal of the Korean Wood Science and Technology
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• v.23 no.1
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• pp.42-48
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• 1995

The purpose of this study is to evaluate the efficacy of metabolites produced form Streptomyces rimosus in controlling the growth of sapwood - inhabiting fungi. In order to carry out this task, the following specific fungi were tested : sapstain fungi - Ceratocystis pilifera, Ceratocystis piceae, and Aureobasidium pullulans ; mold fungi - Trichoderma hazianum, Trichoderma viride, Penicillium cirtrinum, and Aspergillus niger. Based on the tests, the following observations can be drawn. 1. The conidial germination of sapstain and mold fungi was completely inhibited leaving a clear zone around the paper disc treated with metabolites. The best inhibition was observed in A. pullulans plate and the least in T. viride. 2. Concentration of SB medium for the production of metabolites from St, rimosus affected antifungal activity of metabolites against sapwood - inhabiting fungi. Metabolites prepared from 1/3${\times}$SB medium showed the best activity and the least activity was observed in metabolites form 1/4${\times}$medium. 3. in vivo and in vitro test using wood blocks, treatment of pine sapwood blocks with metabolites also inhibited conidial germination and thus prevented discoloration. 4. Treatment with metabolites did not change the macroscopic structure of wood and did not cause the discoloration of the surface of wood by pigments produced form St. rimosus. In conclusion the results of this study indicate that antifungal metabloites of St, rimosus could be used for the biological control of sapstain and mold fungi.

• Journal of the Korean Society of Food Science and Nutrition
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• v.26 no.5
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• pp.767-774
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• 1997

For the standardization and quality improvement of traditional Korean Nuruk, 120 strains of fungi were isolated from Nuruks and 18 strains of them were selected as strains analysing the amylase and flavor. The genera of these fungi were identified as Aspergillus sp. (14 strains), Penicillium sp. (3 strains) and Rhizopus sp. (1 strains) by the conventional slide culture. Most of these fungi showed a better productivity of the saccharogenic and dextrinogenic enzymes in raw wheat bran culture than in cooked wheat bran culture. The ability of acid and flavor production was good in the raw wheat bran culture, and aflatoxins were not produced under the same culture. Penicillium sp. and Rhizopus sp. had high cell growth and amylast activity. Mixed culture of Aspergillus sp. No.3-6 and Penicillium sp. No.7-7 revealed a high liquefying and saccharifying activity as well as high flavors production. These results indicated that these fungi was proper strains for making Nuruk of good quality.

• The Plant Pathology Journal
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• v.22 no.4
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• pp.381-385
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• 2006

Antifungal activity of Korean and Chinese lichen-forming fungi(LFF) was evaluated against plant pathogenic fungi of Botryosphaeria dothidea, Botrytis cinerea, Diaporthe actinidiae, Pestalotiopsis longiseta, Pythium sp., Rhizoctonia solani, and Sclerotium cepivorum. The LFF were isolated from Cladonia scabriuscula, Melanelia sp., Nephromopsis asahinae, Nephromopsis pallescens, Parmelia laevior, Pertusaria sp., Ramalina conduplicans, Ramalina sinensis, Ramalina sp., Umbilicaria proboscidea and Vulpicida sp. with discharged spore method. The isolates were deposited in the herbarium of Korean Lichen Research Institute(KoLRI) in Sunchon National University. The LFF of Melanelia sp., P. laevior, Pertusaria sp., R. conduplican and Ramalina sp. exhibited strong antifungal activity against all of the pathogenic fungi examined. Among them, LFF of P. laevior showed more than 90% of inhibition in fungal hyphae growth, compared with control. The results imply that LFF can be served as a promising bioresource to develop novel biofungicides. Mass cultivation of the LFF is now under progress in laboratory conditions for chemical identification of antifungal substances.

• Journal of Microbiology and Biotechnology
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• v.2 no.3
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• pp.209-214
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• 1992

Serratia marcescens co-cultured with various phytopathogenic fungi, including Rhizopus stolonifer, Helminthosporium allii, Pyricularia oryzae, Fusarium oxysporium and Collectothricom cassiicola, in an LB- agar medium containing 1.5% swollen chitin, significantly inhibitied fungal growth. Fungal hyphae grew rapidly outward from the culture dish center, but the hyphal extensions of the pathogenic fungi were significantly inhibited in a perimetric contact area with S. marcescens. This was especially evident in pathogenic fungi which have a high chitin content in their cell walls. The extracellular chitinase activities of S. marcescens were increased seven fold by the addition of 1.5% swollen chitin to the LB-broth, compared to chitinase activities in a culture medium without chitin. The type of induction was dependent on the various forms of chitin used. When the culture supernatant of S. marcescens or the chitinases of Streptomyces griceus purchased from Sigma Chemical Co., were incubated with the mycelium of F. oxysporium, the mycelium gradually burst as cultivation time progressed and completely lysed after incubation for 2 days. On the other hand, E. coli extract did not hydrolyze the F. oxysporium mycelium at all. These data showed that the chitinolytic activities of S. marcescens play important roles in the biochemical control of phytopathogenic fungi.

• Journal of Microbiology and Biotechnology
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• v.33 no.8
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• pp.1013-1022
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• 2023

Arbuscular mycorrhizal fungi (AMF) are widespread soil endophytic fungi, forming mutualistic relationships with the vast majority of land plants. Biochar (BC) has been reported to improve soil fertility and promote plant growth. However, limited studies are available concerning the combined effects of AMF and BC on soil community structure and plant growth. In this work, a pot experiment was designed to investigate the effects of AMF and BC on the rhizosphere microbial community of Allium fistulosum L. Using Illumina high-throughput sequencing, we showed that inoculation of AMF and BC had a significant impact on soil microbial community composition, diversity, and versatility. Increases were observed in both plant growth (the plant height by 8.6%, shoot fresh weight by 12.1%) and root morphological traits (average diameter by 20.5%). The phylogenetic tree also showed differences in the fungal community composition in A. fistulosum. In addition, Linear discriminant analysis (LDA) effect size (LEfSe) analysis revealed that 16 biomarkers were detected in the control (CK) and AMF treatment, while only 3 were detected in the AMF + BC treatment. Molecular ecological network analysis showed that the AMF + BC treatment group had a more complex network of fungal communities, as evidenced by higher average connectivity. The functional composition spectrum showed significant differences in the functional distribution of soil microbial communities among different fungal genera. The structural equation model (SEM) confirmed that AMF could improve the microbial multifunctionality by regulating the rhizosphere fungal diversity and soil properties. Our findings provide new information on the effects of AMF and biochar on plants and soil microbial communities.

• Mycobiology
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• v.28 no.4
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• pp.190-192
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• 2000

Antifungal bacteria for biological control of plant diseases or production of novel antibiotics to plant pathogens were isolated in 1997 from various soils of Ansung, Chunan, Koyang, and Paju in Korea. Sixty-four bacterial strains pre-screened from approximately 1,400 strains were tested on V-8 juice agar against eight plant pathogenic fungi using in vitro bioassay technique for inhibition of mycelial growth. Test pathogens were Alternaria mali, Colletotrichum gloeosporioides, C. orbiculare, Fusarium oxysporum f. sp. cucumerinum, F. oxysporum f. sp. lycopersici, Magnaporthe grisea, Phytophthora capsici, and Rhizoctonia solani. A wide range of antifungal activity of bacterial strains was found against the pathogenic fungi, and strain RC-B77 showed the best antifungal activity. Correlation analysis between inhibition of each fungus and mean inhibition of all eight fungi by 64 bacterial strains revealed that C. gloeosporioides would be best appropriate for detecting bacterial strains producing antibiotics with potential as biocontrol agents for plant pathogens.

• Mycobiology
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• v.46 no.1
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• pp.52-63
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• 2018

In our previous studies, Bacillus megaterium KU143, Microbacterium testaceum KU313, and Pseudomonas protegens AS15 have been shown to be antagonistic to Aspergillus flavus in stored rice grains. In this study, the biocontrol activities of these strains were evaluated against Aspergillus candidus, Aspergillus fumigatus, Penicillium fellutanum, and Penicillium islandicum, which are predominant in stored rice grains. In vitro and in vivo antifungal activities of the bacterial strains were evaluated against the fungi on media and rice grains, respectively. The antifungal activities of the volatiles produced by the strains against fungal development and population were also tested using I-plates. In in vitro tests, the strains produced secondary metabolites capable of reducing conidial germination, germ-tube elongation, and mycelial growth of all the tested fungi. In in vivo tests, the strains significantly inhibited the fungal growth in rice grains. Additionally, in I-plate tests, strains KU143 and AS15 produced volatiles that significantly inhibited not only mycelial growth, sporulation, and conidial germination of the fungi on media but also fungal populations on rice grains. GC-MS analysis of the volatiles by strains KU143 and AS15 identified 12 and 17 compounds, respectively. Among these, the antifungal compound, 5-methyl-2-phenyl-1H-indole, was produced by strain KU143 and the antimicrobial compounds, 2-butyl 1-octanal, dimethyl disulfide, 2-isopropyl-5-methyl-1-heptanol, and 4-trifluoroacetoxyhexadecane, were produced by strain AS15. These results suggest that the tested strains producing extracellular metabolites and/or volatiles may have a broad spectrum of antifungal activities against the grain fungi. In particular, B. megaterium KU143 and P. protegens AS15 may be potential biocontrol agents against Aspergillus and Penicillium spp. during rice grain storage.

• Journal of Microbiology and Biotechnology
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• v.23 no.9
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• pp.1269-1278
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• 2013

Crack remediation on the surface of cement mortar using microbiological calcium carbonate ($CaCO_3$) precipitation (MICP) has been investigated as a microbial sealing agent on construction materials. However, MICP research has never acknowledged the antifungal properties of calcite-forming bacteria (CFB). Since fungal colonization on concrete surfaces can trigger biodeterioration processes, fungi on concrete buildings have to be prevented. Therefore, to develop a microbial sealing agent that has antifungal properties to remediate cement cracks without deteriorative fungal colonization, we introduced an antifungal CFB isolated from oceanic islands (Dokdo islands, territory of South Korea, located at the edge of the East Sea in Korea.). The isolation of CFB was done using B4 or urea-$CaCl_2$ media. Furthermore, antifungal assays were done using the pairing culture and disk diffusion methods. Five isolated CFB showed $CaCO_3$ precipitation and antifungal activities against deteriorative fungal strains. Subsequently, five candidate bacteria were identified using 16S rDNA sequence analysis. Crack remediation, fungi growth inhibition, and water permeability reduction of antifungal CFB-treated cement surfaces were tested. All antifungal CFB showed crack remediation abilities, but only three strains (KNUC2100, 2103, and 2106) reduced the water permeability. Furthermore, these three strains showed fungi growth inhibition. This paper is the first application research of CFB that have antifungal activity, for an eco-friendly improvement of construction materials.

• Korean Journal of Microbiology
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• v.42 no.1
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• pp.34-39
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• 2006

Wood-rot fungi produce extracellular lignin-degrading enzymes, the best known of which are lignin peroxidase, Mn-peroxidase and laccase. In this experiment, some of them produced all of three enzymes. Many other wood-rot fungi produced one or two of those enzymes with various combinations. In this experiment, we tried to clarify the relationship between the pattern of enzyme production and degradative activity of several dye compounds. From the 36 strains of 23 species of wood-rot fungi, Mn-peroxidase activity was found in 30 strains of the fungi tested, whereas the activity of lignin peroxidase and laccase was detected in 11 strains and 12 strains of species, repectively, in Kirks low nitrogen media. In relation to the activity of lignin degrading enzymes and degradation of dye compounds, the white-rot fungi with three kinds of enzymes tested showed the best dye decolorizers. The fungi with Mn-peroxidase activity only decolorized poly R-478 and remazol brilliant blue R dye in proportion to the enzyme activity, while methylene blue, bromophenol blue and congo red dye were degraded in regardless of enzyme activity. Those dyes were degraded in relation to the growth rate of mycelium. Brown-rot fungi did not degrade all the dye compounds except bromophenol blue, in spite of moderate growth rate.