• Korean Journal of Ecology and Environment
• /
• v.46 no.2
• /
• pp.251-264
• /
• 2013

This study was conducted to investigate the diversity of ectomycorrhizal fungi by surveying sites from June 2010 to October 2011. The obtained results from investigation were as follows. The total of 2 Kingdom 3 Phylum 6 classes 15 orders 34 families 59 genera and 107 species including saprophytic and ectomycorrhizal fungi was investigated. A total of 10 families 17 genera 49 species (801 ea.) of ectomycorrhizal mushroom was investigated. The mushrooms are classified into 28 families 51 genera and 99 species in Basidiomycota, 5 families 7 genera and 7 species in Ascomycota and 1 families 1 genera and 1 species in Amoebozoa. Dorminant species were Amanitaceae (14 species) followed by Russulaceae (12 species) and Boletaceae (11 species). The populaion ectomycorrhizal mushroom was highest in sites 1 and 2, and sites 4 and 5 occurrence rarely. The mushroom occurrence of ectomycorrhizal fungi was closely related to climatic conditions such as high air temperature and lots of rainfall from July to August. The environment factors which have a favorable influence of mushroom occurrence were soil pH, organic matter content of soil and air temperature of climatic environment.

• Journal of Mushroom
• /
• v.3 no.2
• /
• pp.52-59
• /
• 2005

The Aphyllophorales is a large order containing about 2,000 known species. Many of these are the bracket and coral fungi. The vast majority of these fungi are saprophytic on the plant debris. Many species are significant in decomposing plant remains, as they are able to digest cellulose or lignin that occurs in plant cell walls. Many of these fungi have been involved in everyday human affairs. A few were used medicinally by the Greeks and Romans as a remedy for many complaints, including colic, fractured limbs and bruises. Other bracket fungi have been used as curry combs for horses, as snuff, as razor strops and as a source of dye for clothing. The texture of the basidiocarp may be similar to that of cork, wood, leather, paper, or cartilage. Unlike the basidiocarps of the Order Agaricales, the basidiocarps of the Aphyllophorales are not fleshly and moist. Division of the members of the Aphyllophorales into genera was originally made on the basis of gross morphology of the basidiocarp and hymenium and Donk(1964) recognizes 22 families in this order. The species and genus whose typical in Aphylloporales were listed in Table. with related information. The ITS region sequence of some genus were found by BLAST search. Sequences retrieved from GenBank were visually aligned by the program CLUSTAL G. As a result, the medicinal mushroom was separated in four groups. In this multiple alignment, the sequence analysis among Fomes group, Inonotus group and Phellinus group showed high genetic similarity except Hericium group and Sparassis group.

• Microbiology and Biotechnology Letters
• /
• v.12 no.4
• /
• pp.299-304
• /
• 1984

Saprophytic microorganisms of onion bulbs in Korea were confirmed, and effects of temperature, humidity and fumigation by Tetrachloro isophthalonitrile on Botrytis-rot were investigated in order to decrease storage loss of onions. Dominant saprophytes were Botrytis, Penicillium and Fusarium as molds which were all pathogens, and Erwinia and Pseudomonas as bacteria of which Pseudomonas was a non-pathogen. Botrytis-rot was most effectively suppressed by temperature. At $0^{\circ}C$, the incubation days at which 50% area of one onion leaf-fragment (2.5$\times$2.5cm) inoculated by Botrytis was rotten were 26.2 days and the rotting was delayed more by 21.8 days than at $25^{\circ}C$. For humidity, the effect was pretty insignificant in contrast with temperature effect. At RH 70% and $0^{\circ}C$, the incubation days at which 50% area of one onion leaf-fragment was rotten were 28.0 days and the rotting was delayed more by 1.8 days than at RH9o% and $0^{\circ}C$. By fumigation, the rotting was delayed by 3.8 days at RH 70% and $0^{\circ}C$. In case of slightly infected samples, temperature effect was reduced and the effects of humidity and fumigation were ignored, which implies that storage samples should be healthy.

• 한국균학회소식:학술대회논문집
• /
• 2015.11a
• /
• pp.41-41
• /
• 2015

Oomycetes belong to the kingdom Straminipila, a remarkably diverse group which includes brown algae and planktonic diatoms, although they have previously been classified under the kingdom Fungi. These organisms have evolved both saprophytic and pathogenic lifestyles, and more than 60% of the known species are pathogens on plants, the majority of which are classified into the order Peronosporales (includes downy mildews, Phytophthora, and Pythium). Recent phylogenetic investigations based on DNA sequences have revealed that the diversity of oomycetes has been largely underestimated. Although morphology is the most valuable criterion for their identification and diversity, morphological species identification is time-consuming and in some groups very difficult, especially for non-taxonomists. DNA barcoding is a fast and reliable tool for identification of species, enabling us to unravel the diversity and distribution of oomycetes. Accurate species determination of plant pathogens is a prerequisite for their control and quarantine, and further for assessing their potential threat to crops. The mitochondrial cox2 gene has been widely used for identification, taxonomy and phylogeny of various oomycete groups. However, recently the cox1 gene was proposed as a DNA barcode marker instead, together with ITS rDNA. To determine which out of cox1 or cox2 is best suited as universal oomycete barcode, we compared these two genes in terms of (1) PCR efficiency for 31 representative genera, as well as for historic herbarium specimens, and (2) in terms of sequence polymorphism, intra- and interspecific divergence. The primer sets for cox2 successfully amplified all oomycete genera tested, while cox1 failed to amplify three genera. In addition, cox2 exhibited higher PCR efficiency for historic herbarium specimens, providing easier access to barcoding type material. In addition, cox2 yielded higher species identification success, with higher interspecific and lower intraspecific divergences than cox1. Therefore, cox2 is suggested as a partner DNA barcode along with ITS rDNA instead of cox1. Including the two barcoding markers, ITS rDNA and cox2 mtDNA, the multi-locus phylogenetic analyses were performed to resolve two complex clades, Bremia lactucae (lettuce downy mildew) and Peronospora effuse (spinach downy mildew) at the species level and to infer evolutionary relationships within them. The approaches discriminated all currently accepted species and revealed several previously unrecognized lineages, which are specific to a host genus or species. The sequence polymorphisms were useful to develop a real-time quantitative PCR (qPCR) assay for detection of airborne inoculum of B. lactucae and P. effusa. Specificity tests revealed that the qPCR assay is specific for detection of each species. This assay is sensitive, enabling detection of very low levels of inoculum that may be present in the field. Early detection of the pathogen, coupled with knowledge of other factors that favor downy mildew outbreaks, may enable disease forecasting for judicious timing of fungicide applications.

• The Korean Journal of Mycology
• /
• v.42 no.3
• /
• pp.219-224
• /
• 2014

A gram-negative bacterium was isolated from spent substrate of Agaricus bisporus and showed marked antagonistic activity against Pseudomonas tolaasii. The bacterium was identified as Pseudomonas azotoformans by based on the cultural, biochemical and physiological characteristics, and 16S rRNA gene sequence. The isolated bacterium was saprophytic but not parasitic nor pathogenic to cultivation mushroom. The isolated bacterium for P. tolaasii cell was not sufficient for inhibition in vitro. Control efficacy of Pseudomonas azotoformans HC5 to brown blotch of P. tolaasii was 73, 78, and 71% on A. bisporus, Flammulina velutipes, and Pleurotus ostreatus, respectively. In the future, the suppressive bacterium may be useful for development of a biocontrol system.

• 한국균학회소식:학술대회논문집
• /
• 2018.05a
• /
• pp.13-13
• /
• 2018

Alternaria is a ubiquitous fungal genus, widely distributed in the environment and a range of different habitats. It includes both plant pathogenic and saprophytic species, which can affect crops in the field or cause post-harvest spoilage of plant fruits and kernels. Numerous Alternaria species cause damage to agricultural products including cereal grains, fruits and vegetables, and are responsible for severe economic losses worldwide. Most Alternaria species have the ability to produce a variety of secondary metabolites, which may play important roles in plant pathology as well as food quality and safety. Alternariol (AOH), alternariol monomethyl ether (AME), tenuazonic acid (TeA), tentoxin (TEN) and altenuene (ALT) are considered the main Alternaria compounds thought to pose a risk to human health. However, food-borne Alternaria species are able to produce many additional metabolites, whose toxicity has been tested incompletely or not tested at all. Both alternariols are mutagenic and their presence in cereal grain has been associated with high levels of human esophageal cancer in China. TeA exerts cytotoxic and phytotoxic properties, and is acutely toxic in different animal species, causing hemorrhages in several organs. The possible involvement of TA in the etiology of onyalai, a human hematological disorder occurring in Africa, has been suggested. Altertoxins (ALXs) have been found to be more potent mutagens and acutely toxic to mice than AOH and AME. Other metabolites, such as TEN, are reported to be phytotoxins, and their toxicity on animals has not been demonstrated up to now. Vegetable foods infected by Alternaria rot are obviously not suitable for consumption. Thus, whole fresh fruits are not believed to contribute significantly with Alternaria toxins to human exposure. However, processed vegetable products may introduce considerable amounts of these toxins to the human diet if decayed or moldy fruit is not removed before processing. The taxonomy of the genus is not well defined yet, which makes it difficult to establish an accurate relationship between the contaminant species and their associated mycotoxins. Great efforts have been made to organize taxa into subgeneric taxonomic levels, especially for the small-spored, food associated species, which are closely related and constitute the most relevant food pathogens from this genus. Several crops of agricultural value are susceptible to infection by different Alternaria species and can contribute to the entry of Alternaria mycotoxins in the food chain. The distribution of Alternaria species was studied in different commodities grown in Argentina. These food populations were characterized through a polyphasic approach, with special interest in their secondary metabolite profiles, to understand their full chemical potential. Alternaria species associated with tomato, bell pepper, blueberry, apples and wheat cultivated in Argentina showed a surprisingly high metabolomic and mycotoxigenic potential. The natural occurrence of Alternaria toxins in these foods was also investigated. The results here presented will provide background for discussion on regulations for Alternaria toxins in foods.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.21 no.1
• /
• pp.97-100
• /
• 1992

The optimum condition for the extraction of antimicrobial substance from Lithospermi radix was investigated. For the purpose of obtaining basic data for the development of natural preservatives and for the prevention of food poisoning accidents, its antimicrobial activity was tested against several kinds of saprophytic microbes and food poisoning bacteria. The optimum condition for extraction of antimicrobial substance was to steep Lithospermi radix into 95% ethanol for 24 hours at room temperature. Antimicrobial activity was observed at the pH range $5.0{\sim}8.0$, but its activity became stronger at acidic condition. The result of ion exchange chromatography was showed that the antimicrobial activity of anionic portion was more apparent than that of cationic portion. The antimicrobial activity against Gram positive bacteria was stronger than that of Gram negative bacteria and the growth of food poisoning bacteria such as S. aureus and V. parahaemolyticus was inhibited in the concentration of 0.1% for 48 hours. As for mold and yeast, the growth of some kinds of these organisms was inhibited in the concentration of 0.1 % for 48 hours and the growth of nearly all the fungi was inhibited in the concentration of 0.15% for 96 hours.

• Korean journal of applied entomology
• /
• v.27 no.3
• /
• pp.149-158
• /
• 1988

Nematophagous fungi were successfully isolated by baited plating, centrifugation technique of soil, and direct isolation from naturally ingested nematodes. Predominant seven fungi isolated were identified as Artheobotrys arthroboteyides, A.conoides, A. oligospora, Dactylella lobata, Fusatium oxysporum, Monacrosporium ellopsoporum and Harposporium anguillu-lae. Of these, six fungi were tested for cultural characteristics except. H, anguillulae, extre-mely fastidious fungus in artificial media. Among 14 media tested in this experiment, Corn-meal Agar (CMA) and Oatmeal Agar (OMA) were the most suitable media for growing all six nematophagous fungi. Weakly saprophytic M. ellipsospoyum also grew vigoroualy on these two media. The radial growth, dry weight and sporulation of the fungi tested were quite diverse depending on the culture media. D. lobata revealed good growth and abundantly sporulated on Glucoes Peptone Agar (GPA). Although over-all growth of F, oxysporum was not satisfactory on Sucrose Nitrate Agar (SNA), the sporulation was best on this medium. Optimum conditious for mycelial growth and sporulation of nematophagous fungi ranged pH 5-8 and 20-$30^{\circ}C$ on SNA. D. lobata and F, oxysporum grew vigorously and most profusely sporulated on all media tested. They turned out an most promising biocontrol agents for their aggressive growth and sporulation over the ranges of temperature and pH ranges.

• Korean Journal of Environmental Biology
• /
• v.17 no.4
• /
• pp.439-448
• /
• 1999

To investigate the population dynamics and survival of Genus Vibrio, population densities of aerobic saprophytic bacteria and Vibrio groups were measured 4 times in the intertidal waters of the Yellow Sea near Kunsan from November, 1997 to June, 1998. The distribution of heterotrophic bacteria during the survey periods by plate count and direct count method ranged from 1.2$\pm$0.6$\times$10$^3$~2.0$\pm$1.5$\times$10$^4$CFU ml­$^1$and from 6.0$\pm$4.0$\times$10$^{5}$ ~1.9$\pm$1.5$\times$10$^{7}$ cells ml­$^1$, respectively. Vibrio groups were distributed in the range of 1$\times$10 and 6$\pm$2.2$\times$10$^2$CFU ml­$^1$. The proportion of Vibrio groups to total heterotrophic bacteria was between 0.1 and 6% during the survey periods. A total of 51 isolates was obtained from TCBS agar plates and identified to species level by Biolog Identification System$^{TM}$. As a result, dominant genera were V, mediterranei, V aitguillarum, tr metschnikovii, and V. parahaemolyticus, and isolates were clustered into 26 groups based on the relatedness of average linkage clustering method at 70% level. As for the susceptibility of 51 isolates to 7 kinds of antibacterial agents (gentamicin, ampicillin, chlorarnphenicol, streptomycin, kanamycin, tetracycline, carbenicillin), 96% of isolates showed high resistance to more than one antibiotics and 65% of isolates contained a plasmid, of which size was observed greater than 12 kb, The number of cells of 3 tested strains (V. anguillarum, V. vulnificus, and V. metschnikovii) in filtered aged seawater decreased by approximately 1 to 5 orders of magnitude during 30-d incubation. In most cases, the numbers of cells decreased rapidly until day 3, then decreased slowly by day 30. The number of cells incubated at 15$^{\circ}C$ showed higher survival than those at 4$^{\circ}C$ and $25^{\circ}C$. These results may be considered for the basic supporting data in the risk assessment of vibriosis in summer.r.

• Journal of Mushroom
• /
• v.6 no.2
• /
• pp.47-51
• /
• 2008

The Oyster mushroom is saprophytic fungus. The pileus is stemmed at the side and later depressed. It grows to 5-15 cm, and is of grey, grey-lilac, blackish-grey, steel grey, grey-brown, and blue-blackish. Various kinds of Oyster mushrooms such as golden, pink, brown, grey, white, and blue make marketing an interesting challenge depending upon the market niche. A new commercial strain "Chung" of oyster mushroom was developed by hyphal anastomosis. It was improved with hybridization between monokaryotic strain derived from Pleurotus ostreatus ASI 2194 and ASI 2487. The pileus of parental strain ASI 2194 and ASI 2487 was grey and light blue-grey, respectively. Most of intra-specific hybrids between strain ASI 2194 and ASI 2487 were showed similar pileus color of parents. By the way, the pileus color of variety 'Chung' was blue to bluish grey. The optimum temperatures of mycelial growth and fruiting body development was $25{\sim}30^{\circ}C$ and $12{\sim}16^{\circ}C$, respectively.