• Mycobiology
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• v.49 no.3
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• pp.249-257
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• 2021

Plants pollination are conducted through various pollinators such as wind, animals, and insects. Recently, the necessity for artificial pollination is drawing attention as the proportion of natural pollinators involved is decreasing over the years. Likewise, the trade in pollen for artificial pollination is also increasing worldwide. Through these imported pollens, many unknown microorganisms can flow from foreign countries. Among them, spores of various fungi present in the particles of pollen can be dispersed throughout the orchard. Therefore, in this study, the composition of fungal communities in imported pollen was revealed, and potential ecological characteristics of the fungi were investigated in four types of imported pollen. Top 10 operational taxonomic unit (OTU) of fungi were ranked among the following groups: Alternaria sp., Cladosporium sp., and Didymella glomerata which belong to many pathogenic species. Through FUNGuild analysis, the proportion of OTUs, which is assumed to be potentially plant pathogens, was higher than 50%, except for apple pollen in 2018. Based on this study of fungal structure, this information can suggest the direction of the pollen quarantine process and contribute to fungal biology in pollen

• Mycobiology
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• v.50 no.4
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• pp.244-253
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• 2022

Trichoderma fungi have been intensively studied for mycoparasitism, and the latter is closely related to their cell-wall degrading enzymes including chitinase. Here, we studied marine-derived Trichoderma spp., isolated from distinct sources and locations, for chitinolytic and antifungal activity. Based on morphological and phylogenetic analyses, two strains designated GJ-Sp1 and TOP-Co8 (isolated from a marine sponge and a marine alga, respectively) were identified as Trichoderma bissettii. This species has recently been identified as a closely related species to Trichoderma longibrachiatum. The extracellular crude enzymes of GJ-Sp1 and TOP-Co8 showed activities of chitobiosidase and b-N-acetylglucosaminidase (exochitinase) and chitotriosidase (endochitinase). The optimum chitinolytic activity of the crude enzymes was observed at 50 ℃, pH 5.0, 0-0.5% NaCl concentrations, and the activities were stable at temperatures ranging from 10 to 40 ℃ for 2 h. Moreover, the crude enzymes showed inhibitory activity against hyphal growth of two filamentous fungi Aspergillus flavus and Aspergillus niger. To the best of our knowledge, this is the first report of the chitinolytic and antifungal activity of T. bissettii.

• Journal of Microbiology and Biotechnology
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• v.33 no.2
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• pp.251-259
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• 2023

Immobilizing microalgae cells in a hyphal matrix can simplify harvest while producing novel mycoalgae products with potential food, feed, biomaterial, and renewable energy applications; however, limited quantitative information to describe the process and its applicability under various conditions leads to difficulties in comparing across studies and scaling-up. Here, we demonstrate the immobilization of both active and heat-deactivated marine diatom Phaeodactylum tricornutum (UTEX 466) using different loadings of fungal pellets (Aspergillus sp.) and model the process through kinetics and equilibrium models. Active P. tricornutum cells were not required for the fungal-assisted immobilization process and the fungal isolate was able to immobilize more than its original mass of microalgae. The Freundlich isotherm model adequately described the equilibrium immobilization characteristics and indicated increased normalized algae immobilization (g algae removed/g fungi loaded) under low fungal pellet loadings. The kinetics of algae immobilization by the fungal pellets were found to be adequately modeled using both a pseudo-second order model and a model previously developed for fungal-assisted algae immobilization. These results provide new insights into the behavior and potential applications of fungal-assisted algae immobilization.

• Microbiology and Biotechnology Letters
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• v.40 no.1
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• pp.23-29
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• 2012

To isolate a novel antifungal compound, we obtained 100 kinds of endolichenic fungi from Korean Lichen & Allied Bioresources Center and examined their antifungal capability. Three fungi Usnea rigidula (2326), Parmotrema pseudotinctorum (2202) and Myelochroa sp. (2292) showed high antifungal activity against Candida albicans when they grew in both liquid and solid media. We extracted the culture supernatants of these three fungi with chloroform and then with ethyl acetate. Chloroform fraction exhibited the highest antifungal activities when those fractions were examined for the growth inhibition of Candida albicans with disc diffusion method. The chloroform faction was on further analysis with $C_{18}$ column chromatography to see whether the inhibitors are already known or not. Two peak fractions were collected from 4-day culture extract for Usnea rigidula and from 6-day culture extract for Parmotrema pseudotinctorum on the HPLC. A peak fraction from chloroform extracts of 4-day culture filtrate of Parmotrema pseudotinctorum showed higher antifungal activities against C. albicans and C. glabrata than another peak fraction. It appears that the antifungal materials are relatively nonpolar as usnic acid often found in lichenic fungi.

• Journal of Korean Society of Environmental Engineers
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• v.30 no.3
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• pp.271-277
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• 2008

The biofilm of white-rot fungi fully exposed in atmosphere are that operation is easy, management cost and energy waste is low. To develop biofilm of white-rot fungi fully exposed in atmosphere, basic test are as follows. To select most effective microoganism species, investigated treatment characteristics of wastewater containing non-biodegradable material for three species of white-rot fungi(Phanerochaete chrysosporium PSBL-1, Phanerochaete chrysosporium KCTC 6147, Trametes sp. KFCC 10941) and activated sludge. And then investigated attached and detached biomass of selected white-rot fungi species on HBC ring surface. Among the three strains tested, P. chrysosporium PSBL-1 and P. chrysosporium KCTC 6147 showed higher efficiency for organics removal than Trametes sp. KFCC 10941, and P. chrysosporium PSBL-1 showed higher efficiency for nitrogen removal than P. chrysosporium KCTC 6147 and Trametes sp. KFCC 10941. Respectively, 51$\sim$59.8%, 57.5$\sim$60.3% of NBDCOD was removed for P. chrysosporium PSBL-1 and P. chrysosporium 6147 in pH 3.5$\sim$5.5. TN removal efficiency showed 39.3$\sim$85.3%, 3.4$\sim$7.6% for P. chrysosporium PSBL-1 and P. chrysosporium 6147 in pH 4.5$\sim$11.5 respectively. Considered that white-rot fungi remove organism and nitrogen simultaneously, the microorganism selected white-rot fungi P. chrysosporium PSBL-1. White-rot fungi P. chrysosporium PSBL-1 attached on HBC ring surface 4,538 mg/L, 4,546 mg/L, 4,531 mg/L after 5 minutes, 4,575 mg/L, 4,573 mg/L, 4,568 mg/L after 10 minutes from initial MLSS 4,600 mg/L in pH 4, 7 and 10 respectively. Also detached biomass is negligible from right after attachment to 10 day in pH 4, 7 and 10.

• Horticultural Science & Technology
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• v.29 no.6
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• pp.575-582
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• 2011

This experiment was conducted to study the qualitative changes of grafted cactus after harvest and to examine the decomposition characteristics of pathogenic fungi which occurs or grows during the simulated shipping period. Plant materials with four varieties of Gymnocalycium mihanovichii var. friedrichii including, 'Hukwang', 'Huhong', 'Hwangwol', 'Yeunhwa' and two varieties of Chamaecereus silvestrii f. variegate such as 'Goldcrown' and 'Yellowcrown' were used. During the simulated shipping period, the fresh-weight, bulb diameter, carbon dioxide emission rate, and decomposition rate were observed. The regeneration rate and decomposition rate were observed for the grafted cactuses that were placed in a greenhouse environment with a temperature of $28{\pm}12^{\circ}C$ and humidity of $36{\pm}15.3%$ after 40 days of simulated shipping. There were reductions in the fresh-weight and bulb diameter in every variety as time passed while the carbon dioxide emission rate showed no meaningful difference by each variety. Furthermore, the decomposition rate in the scion was higher than in the stock. According to the analysis of pathogenic fungi by decomposition characteristics, Alternaria sp., Cladosporium sp., Colletotrichum sp., Fusarium sp., Penicillium sp. in G. mihanovichii var. friedrichii were found and Alternaria sp., Bipolaris sp., Cladospoirum sp. in C. silvestrii f. variegate were identified. Therefore, to maintain and improve the quality of grafted cactus, it is necessary to analyze the factors of decomposition from the time of harvest until the point of export and develop a process technology to minimize the decomposition rate.

• Microbiology and Biotechnology Letters
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• v.38 no.4
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• pp.373-378
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• 2010

Studies on standardization and quality upgrade of nuruk which is a basic component in brewing are required to increase the quality level of Korean traditional rice wines and to develop the technology for practical use of it. It is important to isolate best strains, to improve the properties and effectively preserve them for brewing industry. In this study, 16 commercial nuruk samples were obtained from the commercial markets located in Chungcheong areas in Korea. 174 fungal strains were isolated from the samples on DG18 medium using a dilution plating method and then screened for enzyme activity and acid production. The active strains were identified based on the morphological characteristics and ITS sequence analysis. Out of 174 strains, 12 strains showed high amylase activity. Especially, Rhizopus sp. CN084, CN174, Aspergillus sp. CN161 and Mycocladus sp. CN042 showed high saccharogenic power and dextrinogenic enzyme activity on cooked wheat bran medium. On the other hand, Aspergillus sp. CN010, CN161, Rhizopus sp. CN105, CN168 and Rhizomucor sp. CN088 produced high acid production on the same medium. Our results showed that the active strains may be used as microbial sources for nuruk starter with good quality in brewing.

• Journal of Microbiology and Biotechnology
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• v.23 no.6
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• pp.856-863
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• 2013

Application of rhizospheric fungi is an effective and environmentally friendly method of improving plant growth and controlling many plant diseases. The current study was aimed to identify phytohormone-producing fungi from soil, to understand their roles in sesame plant growth, and to control Fusarium disease. Three predominant fungi (PNF1, PNF2, and PNF3) isolated from the rhizospheric soil of peanut plants were screened for their growth-promoting efficiency on sesame seedlings. Among these isolates, PNF2 significantly increased the shoot length and fresh weight of seedlings compared with controls. Analysis of the fungal culture filtrate showed a higher concentration of indole acetic acid in PNF2 than in the other isolates. PNF2 was identified as Penicillium sp. on the basis of phylogenetic analysis of ITS sequence similarity. The in vitro biocontrol activity of Penicillium sp. against Fusarium sp. was exhibited by a 49% inhibition of mycelial growth in a dual culture bioassay and by hyphal injuries as observed by scanning electron microscopy. In addition, greenhouse experiments revealed that Fusarium inhibited growth in sesame plants by damaging lipid membranes and reducing protein content. Co-cultivation with Penicillium sp. mitigated Fusarium-induced oxidative stress in sesame plants by limiting membrane lipid peroxidation, and by increasing the protein concentration, levels of antioxidants such as total polyphenols, and peroxidase and polyphenoloxidase activities. Thus, our findings suggest that Penicillium sp. is a potent plant growth-promoting fungus that has the ability to ameliorate damage caused by Fusarium infection in sesame cultivation.

• The Korean Journal of Mycology
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• v.19 no.2
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• pp.109-119
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• 1991

The vertical distribution of the fungal population for the soil samples from two sites of producing and nonproducing of Tricholoma matsutake, song-yi mushroom, were examined at Yang­yang and Myung-joo, Gangweon province. By the dilution plate method, a total number of propagu­les of fungi per gram of soil was observed to be low at the song-yi producing sites but high at the song-yi nonproducing sites under the communities of Pinus densiflora. The tendency of the number of fungal propagules were decreased with the increasing vertical depth. In the incuhation method at $42^{\circ}C$, six genera and nineteen species of the fungi were isolated from two sites; Aspergillus fumigatus, Acremonium sp., Talaromyces stipitatus, Penicillium lilacinum, P. oxalicum and Westerdykella multispora. The most dominant species by this method was A. fumigatus. From heat treatment method at $70^{\circ}C$, seven genera and nineteen species were isolated; Aspergillus fumigatus, Alternaria alternata, Neurospora sitophila and Mucor sp.. In the ethanol treatment method, one genera and one species was isolated Mortierella sp.. From the three isolation methods, it was found that the total number of the soil fungi and the frequency of species appeared were the highest at the soil of upper layer whereas the lowest at the soils of lower layer in its vertical distribution.

• Asian-Australasian Journal of Animal Sciences
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• v.32 no.7
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• pp.996-1006
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• 2019

Objective: This study aimed to gain deeper insights into the dynamic changes in spoilage fungi populations during fermentation and the influence of traditional additives on silage quality. Methods: Elephant grass (Pennisetum purpureum) was prepared without any additive (control), and with the addition of 0.5% salt, and 0.5% salt-0.2% sugar mixture. The fungal community was then determined using a classic culturing method and high-throughput sequencing at 0, 5, 15, and 60 days after ensiling. Results: The results showed that the fungal community of elephant grass silage varied significantly between the natural fermentation without any additive and the two additive groups. The diversity and relative abundance of spoilage molds in the control group were much higher than those in the two treatment groups (p<0.05). Three species of yeasts (Candida sp., Pichia sp., Trichosporon sp.) and four spoilage molds (Fusarium sp., Aspergillus sp., Muco sp. and Penicillin sp.) were the predominant fungi in elephant grass during natural fermentation from 0 to 60 days, which were found to be significantly decreased in salt and sugar additive groups (p<0.05). Meanwhile, the diversity and relative abundance of undesirable molds in the 0.5%-salt additive group were the lowest among all groups. Conclusion: Adding salt and sugar, particularly 0.5% salt, is a promising effective approach to reduce the amount of undesirable fungi thus, improving the silage quality of elephant grass in northern Vietnam.