• Journal of Korean Society of Forest Science
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• v.86 no.3
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• pp.399-404
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• 1997

This paper is presenting a practical result of environmental manipulation effect on pine mushroom Tricholoma matsutake yield and a discussion of key factor seeking for improving pine mushroom production by analyzing the effects on mushroom yield for 10 years with applying five kinds of environmental control at the pine stands located in Namwon, Chollabuk-do, Korea. The environmental controls included density control and forest floor manipulations, and the treatments were applied during early summer of 1983. The mushroom yield itself did not show statistically significant differences among the treatments. But, we could manifest the treatment effects by calculating the relative yield in percent on the basis of pretreatment yield collected in 1982. The forest floor manipulation with density control may affect pine mushroom yield in short term, and continuous management should be applied to keep and improve the mushroom production. The fine root activity was the most important factor of pine mushroom production at the Namwon research site since the floor raking resulted in the largest effect on the mushroom yield although the environmental condition for the growth of fungi is important for pine mushroom production. In addition, the pine mushroom forest with sandy soils demands adequate litter layer since the litter removal showed relatively detrimental effects on pine mushroom yield compared to that in litter covered plot at the research site. That is, soil texture should be considered for forest floor manipulation, and it is reconfirmed that the environmental control to improve pine mushroom production should be applied differently by each region.

• Journal of the Korean Society of Food Science and Nutrition
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• v.41 no.3
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• pp.320-326
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• 2012

This study was conducted to investigate the antibacterial and antioxidative activities of water and ethanol extracts from a mixture of roasted coffee and red ginseng. The antibacterial effects of each extract were determined by the classical paper disc method. A water extract of mixture samples inhibited growth of all strains, but antibacterial effects were mostly weakened. Ethanol extracts showed stronger antibacterial effects than water extracts in all strains except Gram negative Escherichia coli and the fungi strain Candida albicans. Also, the antibacterial effect of the Bacillus cereus strain appeared in all samples, and the ES2 sample formed a clear zone of 19 and 20 mm against Pseudomonas aeruginosa and S. Typhimurium respectively (MIC=0.25 and 0.125 mg/mL). Determinations of free radical elimination for the different mixture extracts using 1,1-diphenyl-2-picrylhydrazyl (DPPH) were compared with ascorbic acid and butylated hyderoxytoluene as positive controls. The water and ethanol extracts of mixture samples (100 ${\mu}g/mL$) showed 55.38~60.01% and 59.37~70.50% DPPH scavenging activities, respectively. DPPH scavenging activities of all mixture samples were slightly higher than roasted coffee and red ginseng samples. However, DPPH scavenging activity decreased when red ginseng extract composed more than 70% of the total extract. The total polyphenol in the mixture samples measured by the Folin-Denis method revealed the highest level of polyphenol content in ethanol extract of sample 3, whereas polyphenol content differed with different mixture ratios, ranging from 105.16~119.79 mg/g in ethanol extract. In the water extract, the polyphenol content was greatest with water extract of sample 1, whereas in other samples the content varied from 93.75~109.18 mg/g.

• Korean Journal of Medicinal Crop Science
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• v.9 no.2
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• pp.156-165
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• 2001

Exogeneous application of pokeweed antiviral protein (PAP), a ribosomal-inacivating protein in the cell wall of Phytolacca americana (pokeweed) protects heterologous plants from viral and fungal infection. A cDNA clone of PAP introduced into Scrophularia buergeriana Miquel by thransformation with Agrobacterium tumefaciences. For plant transformation, explants were precultured on shoot induction medium without kanamycin for 2-5 day, and then they were cocultured with Agrobacterium for 10 minutes. The explants were placed on co culture medium in dark condition, $28^{\circ}C$ for 2days. After explants were washed in MS liquid medium, they were transferred into selection medium including kanamycin 50mg/L (MS salts+1mg/ l BAP+2mg/ l TDZ+0,2mg/ l NAA+MS vitamin+3% sucrose+0.8% agar, pH5.8). From PCR analysis, NPT II band was confirmed in transgenic plant genome and showed resistance against fungi in antifungal activity test. Micro assay to which protein extracted from transgenic line were added, revealed hyphae growth inhibition and no spore germination at high concentration. The characteristics of inhibited hyphae was represented transparent and thin. Expression of PAP in transgenic plants offers the possibility of developing resistance to viral and fungal infection.

• Applied Biological Chemistry
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• v.45 no.2
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• pp.71-76
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• 2002

Several antagonistic bacteria, SD-1, 4, 10, 11, 14, 15, and 16, which have strong CMCase and amylase activities, were isolated from the fermented mushroom media. Among them, SD-1, 10, 11, and 15 have strong antibacterial activities against the mushroom pathogenic bacteria Pseudomonas sp., and SD-1, 10, 11, 14, and 16 have strong antifungal activities against the mushroom pathogenic fungi, Trichoderma sp. SD-14, 15, and 16 did not inhibit the growth of mushroom Pleurotus eryngii ASI-2302, and Pleurotus ostreatus ASI-2042 and ASI-2180. When the culture broth mixture of the seven bacterial strains was applied to the mushroom media, the growths of pathogens, Pseudomonas sp. and Trichoderma sp., were inhibited.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.61 no.1
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• pp.9-16
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• 2016

To investigate the effect of soluble silicate zeolite dressing of the rice against bakanae disease, field trial in reclaimed land and in vitro were carried out. The coated rice seeds (SCS) which were dressed with the mixture of 25% silicic acids (binder), and the zeolite (coating powder). In wet direct seeding, uniform scattering of rice seeds on the soil surface and the better seedling establishment were shown in SCS treatment plots. The incidence of bakanae disease began from the mid tillering stage toward the heading stage. Around heading stage, the ratio of infected tillers reached its highest point by 9.9% in non-SCS treatment plots. While, in SCS treatment plots, the ratio of infected tillers was no more than 0.01%. The vitality of the pathogenic fungi of bakanae disease in the SCS and non-SCS samples were assessed. Samples were incubated for one week keeping proper humidity at $30^{\circ}C$ after inoculated with panicles of infected rice plants from experimental field plots. In non-SCS treatment, pinkish colonies were formed on the grain surface of panicle of infected plants, and mycelium, macro-conidia and micro-conidia were developed actively inside part of infected grain inoculated. While in SCS treatment, micro-conidia and mycelium were not survived and the growth of macro-conidia, mycelia were greatly inhibited and withered. Based on the results, it is concluded that the environmental friendly control of bakanae disease by use of SCS is possible and soluble silicate can be applied as agents for replacement of seed disinfection.

• 한국균학회소식:학술대회논문집
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• 2014.10a
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• pp.25-25
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• 2014

Three species of Fusarium, F. fujikuroi, F. verticillioides and F. proliferatum, are known to be associated with bakanae disease of rice [1, 2]. F. fujikuroi infects rice flowers and survive in endosperm and embryo of the seeds. Infected seed is an important source of primary inoculum of pathogens [3]. Seeds of rice (Oryza sativa cv. Boramchan) collected from bakanae-infected field were found to be 96% infected with Fusarium sp., 52% with F. fujikuroi, 42% with F. verticillioides, and 12% with F. proliferatum as determined by incubation method and species-specific PCR assays. F. fujikuroi was detected at lemma/palea, endosperm and embryo whereas F. verticillioides and F. proliferatum were recovered only from lemma/palea by means of component plating test. Seed disinfection methods have been developed to control bakanae disease and prochloraz has been most widely used for rice seeds. Two chemicals formulated with prochloraz (PC 1) and prochloraz + hexaconazole (PC 2) that inhibit biosynthesis of ergosterol strongly reduced the incidence of Fusarium spp. on selective media to 4.7% and 2.0%, respectively. Disease symptoms of rice seedlings in nursery soil were alleviated by chemical treatment; seedlings with elongated leaves or wide angle between leaf and stem were strikingly reduced from 15.6 to 3.2% (PC 1) and 0 (PC 2), stem rots were reduced from 56.9 to 26.2% (PC 1) and 32.1% (PC 2), and normal seedling increased from 0.4 to 13.3% (PC 2). Prochloraz has some disadvantages and risks such as the occurrence of tolerant pathogens [4] and effects on the sterol synthesis in animals and humans [5]. For these reasons, it is necessary to develop new disinfection method that do not induce fungal tolerance and are safe to humans and animals. Chlorine dioxide ($ClO_2$), that is less toxic, produces no harmful byproducts, and has high oxidizing power, has been reported to be effective at disinfection of several phytopathogenic fungi including Colletotrichum spp. and Alternaria spp. [6]. Gaseous $ClO_2$ applied to rice seeds at a concentration of 20 ppm strongly suppressed mycelial growth of Fusarium fujikuroi, F. verticillioides and F. proliferatum. The incidence of Fusarium spp. in dry seed with 8.7% seed moisture content (SMC) tended to decrease as the concentration of $ClO_2$ increased from 20 to 40 ppm. Applying 40 ppm $ClO_2$ at 90% relative humidity, incidence was reduced to 5.3% and resulted in significant reduction of disease symptoms on MS media. In nursery soil, stem rot was reduced from 56.9 to 15.4% and the number of normal seedlings increased from 0.4 to 25.5%. With water-soaked seeds (33.1% SMC) holding moisture in the endosperm and embryo, the effectiveness of disinfection using $ClO_2$ increased, even when treated with only 20 ppm for four hours. This suggests that moisture was a key element for action of $ClO_2$. Removal of the palea and lemma from seeds significantly decreased the incidence of Fusarium spp. to 3.0%. Seed germination appeared to decrease slightly by water-soaking at $30^{\circ}C$ because of increased SMC and by physical damage of embryos from hulling. These results indicate that the use of gaseous $ClO_2$ was effective as a means to disinfect rice seeds infected with Fusarium spp. and that moisture around the pathogens in the seed was an important factor for the action of $ClO_2$. Further investigations should be conducted to ascertain the best conditions for complete disinfection of Fusarium spp. that infect deep site of rice seeds.

• Journal of Life Science
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• v.25 no.2
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• pp.237-242
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• 2015

The use of calcite-forming bacteria (CFB) in crack remediation and durability improvements in construction materials creates a permanent and environmentally-friendly material. Therefore, research into this type of application is stimulating interdisciplinary studies between microbiology and architectural engineering. However, the mechanisms giving rise to these materials are dependent on calcite precipitation by the metabolism of the CFB, which raises concerns about possible hazards to cement-based construction due to microbial metabolic acid production. The aim of this study was to determine target microorganisms that possibly can have bio-corrosive effects on cement mortar and to assess multi-functional CFBs for their safe application to cement structures. The chalky test was first used to evaluate the $CaCO_3$ solubilization feature of construction sites by fungi, yeast, bacterial strains. Not all bacterial strains are able to solubilize $CaCO_3$, but C. sphaerospermum KNUC253 or P. prolifica KNUC263 showed $CaCO_3$ solubilization activity. Therefore, these two strains were identified as target microorganisms that require control in cement structures. The registered patented strains Bacillus aryabhatti KNUC205, Arthrobacter nicotianae KNUC2100, B. thuringiensis KNUC2103 and Stenotrophomonas maltophilia KNUC2106, reported as multifunctional CFB (fungal growth inhibition, crack remediation, and water permeability reduction of cement surfaces) and isolated from Dokdo or construction site were unable to solubilize $CaCO_3$. Notably, B. aryabhatti KNUC205 and A. nicotianae KNUC2100 could not hydrolyze cellulose or protein, which can be the major constituent macromolecules of internal materials for buildings. These results show that several reported multi-functional CFB can be applied to cement structures or diverse building environments without corrosive or bio-deteriorative risks.

• Korean journal of applied entomology
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• v.49 no.4
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• pp.417-422
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• 2010

Cultural characteristics Lecanicillium lecani Btab01 and its insecticidal activity against tobacco whitefly (Bemisia tabaci) were investigated. On potato dextrose agar, tryptic soy agar and SDA+Y media, mycelial growth of L. lecani Btab01 was best at $20{\sim}25^{\circ}C$ and suppressed above $28^{\circ}C$. Both solid culture and liquid culture of L. lecani Btab01 showed high insecticidal activity, 93.9 and 98.3% respectively, against nymph of tobacco whitefly, but there is no significant difference. When culture of L. lecani Btab01 was treated at the concentration of $10^5$, $10^6$, $10^7$ and $10^8$ cfu/ml, their insecticidal activity were 5.8%, 33.8%, 77.3% and 98.5% respectively, and $LT_{50}$ values were 16.1 days, 7.3 days, 5.1 days and 3.5 days respectively. When nymphs were treated by the cultures of L. lecani Btab01 and maintained under saturated condition for zero hour, 24 hours and 168 hours, their control activities were 0%, 20.3% and 100% respectively. Spore germination of L. lecani Btab01 was increased about two times by adding edible oil. When L. lecani Btab01 was treated to control nymph with 0.1% edible oil, it showed high control activity(98.6%) compared to single treatment of L. lecani Btab01 (79.9%).

• Journal of the Korean Society of Food Science and Nutrition
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• v.35 no.9
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• pp.1237-1244
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• 2006

In order to ensure a stable supply of grapes for consumers and to extend grape storage, we investigated changes in the quality of grapes (Vitis labruscana) stored after treatment with ethylene absorbent (EA) or activated charcoal (AC). We treated harvested 'Sheridan' and 'Muscat Bailey A' grapes with EA and with 0.1, 0.5, 1.0, and 2.0% (w/w) AC, and stored them at $0{\pm}1^{\circ}C$, $90{\pm}2%$ humidity for 60 days. After the EA or AC treatment, the storability of the 'Sheridan' and 'Muscat Bailey A' grapes was increased, as compared with non treatment, and 'Sheridan' kept better than 'Muscat Bailey A'. The quality of the stored grapes maintained with EA or the amount of AC, which decreased the rate of weight loss, abnormal fruit development, berry abscission, saccharinity, and growth of fungi. The free sugar and anthocyanin contents in the pericarp increased gradually in both 'Sheridan' and 'Muscat Bailey A', and increased more in 'Sheridan'. Conversely, the total acidity of 'Sheridan' and 'Muscat Bailey A' decreased with storage, and decreased less in 'Sheridan'. There were no differences in the free sugar content, anthocyanin content, and total acidity among treatments. The changes in grape quality with storage were delayed in the order of EA, 2% AC, 1% AC, 0.5% AC, and 0.1% AC. Ultimately, we postulate that EA and 2% AC best maintain the qualities of grape, and extend the grape storage period.

• Korean Journal of Soil Science and Fertilizer
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• v.36 no.3
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• pp.134-144
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• 2003

A rhizobacterium Pseudomonas cholororaphis O6 produced several secondary metabolites, such as phenazines, protease, and HCN that may be involved in inhibition of the growth of phytopathogenic fungi. In field study, P. chlororaphis O6 treatment on wheat seed suppressed root rot disease caused by Fusarium culmorum. The major organic acids of cucumber root exudates were fumaric acid, malic acid, benzoic acid, and succinic acid. Glucose and fructose were major monosaccharides in cucumber root exudates. The total amount of organic acids was ten times higher than that of the sugars. P. chlororaphis O6 grew well on cucumber root exudates. The dctA gene of P. chlororaphis O6 consisted of a 1,335 bp open reading frame with a deduced amino acid sequence of 444 residues, corresponding to a molecular size of about 47 kD and pI 8.2. The deduced dctA sequence has ten putative transmembrane domains, as expected of a membrane-embedded protein. Our results indicated that organic acids in cucumber root exudates may play an important role in providing nutrient source for root colonization of biological control bacteria, and the dctA gene of P. chlororaphis O6 may be an important bacterial trait that is involved in utilization of root exudates.