• The Korean Journal of Mycology
• /
• v.21 no.3
• /
• pp.172-187
• /
• 1993

Forty eight fungal isolates were isolated from the maeius collected through the whole nation. Out of them, nine isolate were observed to be zygomyceteous fungi(4 genera and 9 species): Mucor hiemalis, M. circinelloides f. griseo-cyanus, M. circinelloides, M. jansseni, M. racemosus f. racemosus, Mortierella isabellina, Rhizopus stolonifer, R. oryzae, and Absidia corymbifera. Four species(M. circinelloides f. griseo-cyanus, M. hiemalis, M. jansseni, and R. oryzae) identified here were known as species involved in maeiu but not described in detail. The others were first reported as a species inhabiting in the maeiu. Two species of M. hiemalis f. hiemalis. and M. circinelloides f. griseo-cyanus were determined to play a role in biochemical changes of soybean in the fermentation of maeiu. However, the others seldom inhabited but considered to be comtaminated fungi in maeiu.

• The Korean Journal of Mycology
• /
• v.47 no.4
• /
• pp.291-301
• /
• 2019

Nematophagous fungi can capture, kill, and digest nematodes using a specific capturing organ. Of the nematophagous fungi, while Arthrobotrys flagrans and A. superba have been described previously, certain characteristics have not been described. For a detailed description of the two nematophagous fungi, the fungi were isolated from soil samples and produced in a pure culture. Morphological characteristics, such as predatory ability (according to the nematode species), shape, and size of predatory organ, conidia, and chlamydospore were investigated and they were used for identification of the fungal isolates along with molecular phylogenetic analysis. Furthermore, this study provides the classification key for 21 nematophagous species.

• The Korean Journal of Mycology
• /
• v.27 no.1 s.88
• /
• pp.15-19
• /
• 1999

One hundred and six Cordyceps cultures including five cultures of Paecilomyces tenuipes were used for production of artificial fruiting body. In the test of artificial fruiting body formation, no fruiting bodies were induced on media containing PDA and ground silkworm pupae with liquid nitrogen. The best fruiting body formation was showed on media which mixed at the ratio of 1 unsticky rice to 3.5 water. But fruiting bodies formed on media mixed at the ratio 1 unpolished rice to 2.5 water. Optimal temperature in inducing artificial fruiting body was at $20^{\circ}C$. Twenty seven isolates were selected as good cultures for production of artificial fruiting body. Maturation of fruiting bodies incubated on rice grain media was completed for about 50 to 65 days.

• The Korean Journal of Mycology
• /
• v.30 no.1
• /
• pp.11-17
• /
• 2002

This experiment was carried out to study formation of fruitbody with Cordyceps scarabaeicola (EFCC C-252) isolate. This isolate was the one of best fruitbody formation on brown rice 60 g plus 30 g silkworm pupa media among EFCC C-251, EFCC C-252, EFCC C-1092 from EFCC (Entomopathogenic Fungal Culture Collection) of Kangwon National University. Fruiting body was formed only isolate EFCC C-252 among tested isolates on the medium of brown rice (60 g) and silkworm pupae (30 g). The optimal temperature and light for fruiting body formation were $25^{\circ}C$ and fluorescent light (300 lux). The maximal fruiting body formation was observed at 70 g of brown rice and 80 g of silkworm pupa medium which was treated separately. Fruiting body was formed maximally by 2 days interval of irrigation.

• Journal of Microbiology and Biotechnology
• /
• v.16 no.5
• /
• pp.704-715
• /
• 2006

Oil spill was found in 1999 from a diesel storage facility located near the top of Baekun Mountain in Uiwang City. Application of bioremediation techniques was very relevant in removing oil spills in this site, because the geological condition was not amenable for other onsite remediation techniques. For efficient bioremediation, bacterial communities of the contaminated site and the uncontaminated control site were compared using both molecular and cultivation techniques. Soil bacterial populations were observed to be stimulated to grow in the soils contaminated with diesel hydrocarbon, whereas fungal and actinomycetes populations were decreased by diesel contamination. Most of the dieseldegrading bacteria isolated from contaminated forest soils were strains of Pseudomonas, Ralstonia, and Rhodococcus species. Denaturing gradient gel electrophoresis (DGGE) analysis revealed that the profiles were different among the three contaminated sites, whereas those of the control sites were identical to each other. Analysis of 16S rDNA sequences of dominant isolates and clones showed that the bacterial community was less diverse in the oil-contaminated site than at the control site. Sequence analysis of the alkane hydroxylase genes cloned from soil microbial DNAs indicated that their diversity and distribution were different between the contaminated site and the control site. The results indicated that diesel contamination exerted a strong selection on the indigenous microbial community in the contaminated site, leading to predominance of well-adapted microorganisms in concurrence with decrease of microbial diversity.

• The Korean Journal of Mycology
• /
• v.25 no.4 s.83
• /
• pp.320-329
• /
• 1997

Botrytis cinerea isolates obtained from infected plants of cucumber, tomato, and strawberry were divided into three groups (sporing, sclerotial, and mycelial types). Of which sclerotial types were the major group. There were no correlations between morphological phenotypes and responses to benzimidazole and dicarboximide fungicides. External structure of conidia of three phenotypes by scanning electron microscope was the same with verrucose surface. Mycelial type was the most virulent on fruits of eggplants. Comparative tests were carried out to examine correlations between the virulence and production of fungal enzymes such as phenol oxidases, pectin methyl esterases (PME), amylases, cellulases, ureases, ${\beta}-glucosidases$, and proteinases. There was no correlation among the phenotypes in production of phenol oxidases and ${\beta}-glucosidases$. However, there were significantly different from each other in PME, amylase, cellulase, urease, and protease activity.

• The Korean Journal of Mycology
• /
• v.45 no.4
• /
• pp.345-354
• /
• 2017

The leaves of two woody plant species, Pinus densiflora and Aronia melanocarpa, were collected in Korea, and endophytic fungi were isolated from these surface-sterilized leaves. The fungal isolates were identified based on their morphological characteristics and the results of the phylogenetic analysis involving nucleotide sequences of the internal transcribed spacer region (ITS), including 5.8S rDNA, D1/D2 regions of 28S rDNA, and ${\beta}-tubulin$ genes. Pestalotia lawsoniae and Zasmidium fructicola were isolated from Pinus densiflora, and three species, Pestalotiopsis chamaeropis, Pestalotiopsis jesteri, and Stagonosporopsis cucurbitacearum were isolated from Aronia melanocarpa. To the best of our knowledge, these species have not been previously reported in Korea.

• The Plant Pathology Journal
• /
• v.21 no.1
• /
• pp.77-82
• /
• 2005

A summer annual weed of monochoria (Monochoria vaginalis) grows in the edges of rice paddies, ditches, and moist upland throughout Korea. It is very difficult to control with herbicide because of its sulfonylurea resistance. It is very competitive with fast growing pattern, that can cause reducing yields of rice. Brown leaf blight of monochoria (Monochoria vaginalis) occurred naturally in rice paddy, is first reported in Korea. The fungal isolate BWC01-54 was successfully isolated from the diseased leaves of monochoria. The fungus BWC 01-54 was grown well at $25-28^{\circ}C$, conidia of the greysh black brown mycelia were abundant produced on PDA at 15 days. The fungus was grown well in potato dextrose broth at $28^{\circ}C$ and fully grown within 10 days in 250 ml of flask. In host and pathogenicity test, conidia suspension of BWC01-54 was the most effective to control of monochoria compare to others isolates. Typical symptoms having pin point brown lesions were formed on stem and leaf and which severely affected the whole plants ware blighted within two weeks, respectively. Under paddies field condition, conidial suspension of the fungus BWC01-54 gave around 90% control. Therefore, we conclude that the fungus may have a potential as a biological control agent against sulfonylurea resistance weed in rice paddy.

• The Plant Pathology Journal
• /
• v.33 no.3
• /
• pp.318-328
• /
• 2017

Chitinase-producing Paenibacillus elgii strain HOA73 has been used to control plant diseases. However, the antimicrobial activity of its extracellular chitinase has not been fully elucidated. The major extracellular chitinase gene (PeChi68) from strain HOA73 was cloned and expressed in Escherichia coli in this study. This gene had an open reading frame of 2,028 bp, encoding a protein of 675 amino acid residues containing a secretion signal peptide, a chitin-binding domain, two fibronectin type III domains, and a catalytic hydrolase domain. The chitinase (PeChi68) purified from recombinant E. coli exhibited a molecular mass of approximately 68 kDa on SDS-PAGE. Biochemical analysis indicated that optimum temperature for the actitvity of purified chitinase was $50^{\circ}C$. However, it was inactivated with time when it was incubated at $40^{\circ}C$ and $50^{\circ}C$. Its optimum activity was found at pH 7, although its activity was stable when incubated between pH 3 and pH 11. Heavy metals inhibited this chitinase. This purified chitinase completely inhibited spore germination of two Cladosporium isolates and partially inhibited germination of Botrytis cinerea spores. However, it had no effect on the spores of a Colletotricum isolate. These results indicate that the extracellular chitinase produced by P. elgii HOA73 might have function in limiting spore germination of certain fungal pathogens.

• Journal of Food Hygiene and Safety
• /
• v.26 no.4
• /
• pp.361-365
• /
• 2011

To evaluate the indoor air quality of food manufacturing plants, the presence of viable bacteria and fungi was assessed in the indoor air of the facilities at which 9 food items were manufactured. Air samples were collected from the general zone, low clean zone and clean zone of each factory with an air sampler, in combination with plate counts agar using for bacteria, and dichloran-glycerol agar for fungi. The samples were incubated at $25^{\circ}C$ for 4 to 7 days. After culture, the colony forming units (CFU) on each plate were counted and corrected with a positive hole conversion table. The average concentration of bacteria was $2.2{\times}10^3\;CFU/m^3$ in the general zone, $1.2{\times}10^3\;CFU/m^3$ in the low clean zone and $7.3{\times}10^2\;CFU/m^3$ in the clean zone. The average concentration of fungal microbes was $2.5{\times}10^3\;CFU/m^3$ in the general zone, $2.6{\times}10^3\;CFU/m^3$ in the low clean zone, and $2.0{\times}10^2\;CFU/m^3$ in the clean zone. No meaningful differences were detected between the general zone and the low clean zone, but the clean zone had significantly lower concentrations than the other zones. Additionally, the identification of the fungi was performed according to morphological method using a giant culture and slide culture. The fungi were identified as belonging to 18 genera, and the genera Cladosporium(33%), Penicillium(29%) and Aspergillus(26%), predominated. Aspergillus isolates were identified to species level, and A. ochraceus, a mycotoxigenic species, was identified. As part of the effort to control the quality of the indoor air of food manufacturing plants, our results show that continued studies are clearly warranted.