• Mycobiology
• /
• v.44 no.3
• /
• pp.162-170
• /
• 2016

In this paper, we demonstrate the ability of Arabidopsis thaliana to detect different mixtures of volatile organic compounds (VOCs) emitted by the common indoor fungus, Aspergillus versicolor, and demonstrate the potential usage of the plant as a bioindicator to monitor fungal VOCs in indoor air. We evaluated the volatile production of Aspergillus versicolor strains SRRC 108 (NRRL 3449) and SRRC 2559 (ATCC 32662) grown on nutrient rich fungal medium, and grown under conditions to mimic the substrate encountered in the built environment where fungi would typically grow indoors (moist wallboard and ceiling tiles). Using headspace solid phase microextraction/gas chromatography-mass spectrometry, we analyzed VOC profiles of the two strains. The most abundant compound produced by both strains on all three media was 1-octen-3-ol. Strain SRRC 2559 made several terpenes not detected from strain SRRC 108. Using a split-plate bioassay, we grew Arabidopsis thaliana in a shared atmosphere with VOCs from the two strains of Aspergillus versicolor grown on yeast extract sucrose medium. The VOCs emitted by SRRC 2559 had an adverse impact on seed germination and plant growth. Chemical standards of individual VOCs from the Aspergillus versicolor mixture (2-methyl-1-butanol, 3-methyl-1-butanol, 1-octen-3-ol, limonene, and ${\beta}-farnesene$), and ${\beta}-caryophyllene$ were tested one by one in seed germination and vegetative plant growth assays. The most inhibitory compound to both seed germination and plant growth was 1-octen-3-ol. Our data suggest that Arabidopsis is a useful model for monitoring indoor air quality as it is sensitive to naturally emitted fungal volatile mixtures as well as to chemical standards of individual compounds, and it exhibits relatively quick concentration- and duration-dependent responses.

• Korean Journal of Food Science and Technology
• /
• v.24 no.4
• /
• pp.326-329
• /
• 1992

Mucor sp. KCTC 8405P was cultivated in a jar fermentor for the production of fungal lipid containing ${\gamma}-linolenic$ acid with feeding the glucose solution periodically. The transition of the fungal growth into the mycelial phase from yeast-like growth was achieved by pH shift after the first two day of cultivation in the low pH medium and then lipid accumulation was accelerated until the seven day of cultivation, when the glucose in the culture broth was almost consumed. With the culture conditions applied in this experiment, biomass of 99.3 g/l by the dry cell weight and the total extractable lipid of 38.0 g containing 3.5 g/l ${\gamma}-linolenic$ acid were obtained.

• Journal of the Korea Institute of Building Construction
• /
• v.24 no.1
• /
• pp.43-53
• /
• 2024

This research undertook the assessment of six types of silicone sealants prepared. Their resistance to fungi was evaluated according to ASTM G 21, LH specification(LHCS 41 40 12), and the newly instituted KS F ISO 21265 test methods. The findings showed that KS F ISO 21265 test method exhibited the superior discriminative capability in assessing fungal resistance when compared to ASTM G 21 and LH specification(LHCS 41 40 12) test methods. Additionally, it was confirmed that oxime curing sealants demonstrated higher fungal resistance than alkoxy curing sealants. Furthermore, The introduction of a condition to assess fungal resistance after 4 weeks of immersion at 50℃ in KS F ISO 21265 is expected to enable long-term fungal resistance evaluation of sealants.

• The Korean Journal of Ecology
• /
• v.12 no.2
• /
• pp.67-73
• /
• 1989

The action and growth of soil microorganisms were studied in accordance with the leachates from leaf litter over the time lapse, and soil properties and species compositions in studied area were investigated. The investigations of soil microorganisms were made through dividing into two groupsbacterial and fungal groups. The abundance of soil microorganisms showed high correlation with organic matter(0.98) and total nitrogen(0.97) of soil. The amount of soil microorganisms was found the highest in litter layer and the next were humus and A layer in order. The bacterial growth rate in leachates from leaf letter was increased continuously by two weeks. The fungal growth rate was increased only for one week and after then it was decreased abruptly.

• Journal of Microbiology and Biotechnology
• /
• v.24 no.2
• /
• pp.209-216
• /
• 2014

The efficiency of gamma irradiation (0, 1, 5, 10, 15, 20, and 30 kGy) as a sterilization method of corn samples (30 g) artificially contaminated with Fusarium moniliforme stored at normal condition ($25^{\circ}C$ with approximate relative humidity (RH) of 55%) and optimal condition ($25^{\circ}C$ with a controlled RH of 97%) was studied. The results showed that the fungal growth and the amount of fumonisin were decreased as the dose of gamma irradiation increased. Gamma irradiation at 1-5 kGy treatment significantly inhibited the growth of F. moniliforme by 1-2 log reduction on corn samples (P < 0.05). Sublethal effect of gamma irradiation was observed at 10-20 kGy doses after storage, and a complete inactivation required 30 kGy. Fungal growth and fumonisin production increased with higher humidity and longer storage time in all corn samples. This study also demonstrated that there was no strict correlation between fungal growth and fumonisin production. Storage at normal condition significantly resulted in lower growth and fumonisin production of F. moniliforme as compared with those stored at optimal condition (P < 0.05). Gamma irradiation with the dose of ${\geq}5$ kGy followed by storage at normal condition successfully prolonged the shelf life of irradiated corns, intended for human and animal consumptions, up to 7 weeks.

• The Plant Pathology Journal
• /
• v.32 no.4
• /
• pp.281-289
• /
• 2016

The transcription cofactor Swi6 plays important roles in regulating vegetative growth and meiosis in Saccharomyces cerevisiae. Functions of Swi6 ortholog were also characterized in Fusarium graminearum which is one of the devastating plant pathogenic fungi. Here, we report possible role of FgSwi6 in the interaction between F. graminearum and Fusarium graminearum virus 1 (FgV1) strain DK21. FgV1 perturbs biological characteristics of host fungi such as vegetative growth, sporulation, pigmentation, and reduction of the virulence (hypovirulence) of its fungal host. To characterize function(s) of FgSWI6 gene during FgV1 infection, targeted deletion, over-expression, and complementation mutants were generated and further infected successfully with FgV1. Deletion of FgSwi6 led to severe reduction of vegetative growth even aerial mycelia while over-expression did not affect any remarkable alteration of phenotype in virus-free isolates. Virus-infected (VI) FgSWI6 deletion isolate exhibited completely delayed vegetative growth. However, VI FgSWI6 over-expression mutant grew faster than any other VI isolates. To verify whether these different growth patterns in VI isolates, viral RNA quantification was carried out using qRT-PCR. Surprisingly, viral RNA accumulations in VI isolates were similar regardless of introduced mutations. These results provide evidence that FgSWI6 might play important role(s) in FgV1 induced phenotype alteration such as delayed vegetative growth.

• Mycobiology
• /
• v.45 no.3
• /
• pp.172-177
• /
• 2017

The genus Paxillus is characterized by the difficulty of species identification, which results in reproducibility problems, as well as the need for large quantities of fungal inoculum. In particular, studies of Paxillus ammoniavirescens have reported divergent results in the in vitro growth while little is known of its capacity to degrade organic matter. For all the above, and assuming that this variability could be due to an inappropriate culture media, the aim of this study was to analyse growth in different culture media (MMN, MS, and 1/2 MS) and in the case of MMN in presence/absence of two types of organic matter (fresh litter and senescence litter) to probe the saprophytic ability of P. ammoniavirescens. We also evaluated the effects of pH changes in the culture media. Growth kinetics was assessed by weekly quantification of the area of growth in solid culture media over 5 wk, calculating the growth curves and inflection points of each culture media. In addition, final biomass after 5 wk in the different culture media was calculated. Results showed that best culture media are MS and 1/2 MS. Moreover, an improvement in growth in culture media containing decomposing fall litter was observed, leading to confirm differences in the culture media of this species with others of the same genus. Further, we established that all growth media suffered a significant acidification after fungal growth.

• Asian-Australasian Journal of Animal Sciences
• /
• v.13 no.1
• /
• pp.23-30
• /
• 2000

The effects of grass lipids and long chain fatty acids (LCFA; palmitic, stearic and oleic acids), at low concentrations (0.001~0.02%), on the growth and enzyme activity of two strains of anaerobic fungi, monocentric strain Piromyces rhizinflata B157 and polycentric strain Orpinomyces joyonii SG4, were investigated. The addition of grass lipids to the medium significantly (p<0.05) decreased filter paper (FP) cellulose digestion, cellulase activity and fungal growth compared to control treatment. However, LCFA did not have any significant inhibitory effects on fungal growth and enzyme activity, which, however, were significantly (p<0.05) stimulated by the addition of oleic acid as have been observed in rumen bacteria and protozoa. This is the first report to our knowledge on the effects of LCFA on the rumen anaerobic fungi. Continued work is needed to identify the mode of action of LCFA in different fungal strains and to verify whether these microorganisms have ability to hydrogenate unsaturated fatty acids to saturated fatty acids.

• 한국균학회소식:학술대회논문집
• /
• 2014.10a
• /
• pp.48-48
• /
• 2014

Arbuscular Mycorrhizal Fungi(AMF) is widespread symbiont forming mutualistic relationship with plant root in terrestrial forest in ecosystem. They provide improved absorption of nutrient and water, and enhance the resistance against plant pathogen or polluted soil, therefore AM fungi are important for survival and maintaining of individual or community of plant. For last decade, many studies about the functional variation of AM fungi on host plant growth response were showed that different geographic isolates, even same species, have different effect on host plant. However, little was known about functional variation of AM fungal isolates originated single population, which provide important insight about intraspecific diversity of AMF and their role in forest ecosystem. In this study, four AM fungal isolates of Rhizophagus clarus were cultured in vitro using transformed carrot (Daucus carota) root and they showed the difference between isolates in ontogenic characteristics such as spore density and hyphal length. The plant growth response by mycorrhizas were measured also. After 20 weeks from inoculation of these isolates to host plants, dry weight, Root:Shoot ratio, colonization rates and N, P concentration of host plant showed host plant was affected differently by AM fungal isolates. This results suggest that AM fungi have high diversity in their functionality in intraspecific level, even in same population.

• Mycobiology
• /
• v.42 no.2
• /
• pp.100-108
• /
• 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.