• Horticultural Science & Technology
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• v.32 no.6
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• pp.879-886
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• 2014

This study was conducted to test in vitro the antagonistic effect of composted liquid manure (CLM) against soil-borne turfgrass pathogenic fungi, Rhizoctonia solani AG-2-2 (IIIB) (brown patch), R. solani AG-2-2 (IV) (large patch), and Sclerotinia homoeocarpa (dollar spot) for environmentally friendly turfgrass management. CLMs were collected from 9 livestock excretion treatment facilities around the country including Gunwi (GW), Hapcheon (HC), Hoengseong (HS), Icheon (IC), Iksan (IS), Muan (MA), Nonsan (NS), and Yeoju (YJ). CLMs of IC, GW, and IS showed s ignificant (p < 0.05) mycelium growth inhibition that was 17.8%, 20.4%, and 48.0% against R. solani AG-2-2 (IIIB), R. solani AG-2-2 (IV), and S. homoeocarpa, respectively. A t otal of 110 bacterial isolates were obtained from the CLMs that showed antagonistic effects. Among them, 5, 4, and 10 microbe isolates showed promising antifungal activity against mycelium growth of R. solani AG-2-2 (IIIB), R. solani AG-2-2 (IV), and S. homoeocarpa, respectively. The bacterial isolates ICIIIB60, GWIV70, and ISSH20 effectively inhibited the mycelial growth of three soil-borne turfgrass pathogens. Selected bacterial isolates were identified as Alcaligenes sp., Bacillus licheniformis Ab2, and B. subtilis C7-3 through 16s rDNA gene sequence analysis. Among 5 fungicides, the most compatible fungicide with ICIIIB60, GWIV70, and ISSH20 was tebuconazol, toclofos-methyl and toclofos-methyl, respectively. These findings suggested that CLMs could be effectively used not only as organic liquid fertilizer sources but also as biological control agents for soil-borne turfgrass diseases such as brown patch, large patch, and dollar spot.

• Research in Plant Disease
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• v.13 no.2
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• pp.110-114
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• 2007

Anthracnose fungus was most pathogenic on soybean sprout, of the fungi and bacteria isolated from rotten sprout on market. Bacterial strains associated were not virulent. Dry heat (DHT) applied even as high as $65^{\circ}C$ for 30min. was not effective enough to eliminate the artificially inoculated Colletotrichum gloeosporioides propagules from seedllots. Hot water immersion treatment (HWT), at elevated temperature of $55^{\circ}C$ for 20 min, did eliminate the pathogen but reduced seed germinating and retarded sprout growth: Seed germination was practically acceptable when the seedlots were exposed to at $55^{\circ}C$ for 5 min, but about 20% anthracnose propagules survived. Accordingly, we have optimized the HWT scheme for 5 min at $60^{\circ}C$. This scheme was validated, at small to large scale production system, that surely rule out the possible carry over of the bacterial contaminant from seedlots. This result should improve the shelf-life of soybean sprout on the market.

• The Korean Journal of Pesticide Science
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• v.4 no.3
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• pp.7-14
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• 2000

Methanol extracts from 21 grains were tested for fungicidal activities against six phytopathogenic fungi and for insecticidal activities toward five insect pests in a greenhouse. The efficacy varied with both the plant pathogen/insect pest and grain species used. Potent fungicidal activity at 5 mg/pot, were produced from extracts of Elymus sibiricus and Hordeum vulgare var. nudum against Pyricularia grisea and Erysiphe graminis and these of Sesamum indicum (W) and Triticum aestivum against Puccinia recondita and Erysiphe graminis. At 2,500 ppm, potent insecticidal activities were exhibited from the extracts of Fagopyrum esculentum against Myzus persicae and Ischaemum crassipes, and these of Oryzo sativa var. glutinosa, Panicum miliaceum, Setaria italica, Sorghum bicolor, and T. aestivum against Tetranychus urticae. All grain extracts revealed weak or no fungicidal and insecticidal effect against Phytophthora infestans, Plutella xylostella and Spodoptera litura. As a naturally occurring fungicide and insecticide, grain-derived materials described could be useful as new fungicidal and insecticidal products against phytopathogenic fungi and insect pests.

• The Korean Journal of Mycology
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• v.38 no.2
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• pp.120-124
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• 2010

This study was carried out to investigate interaction between mushroom mycelium and microorganisms in cotton waste media for the shelf cultivation of oyster mushroom. Two oyster mushroom farms was selected for this experiment. One was good mushroom farm (farmhouse I) and the other failed mushroom farm (farmhouse II). In farmhouse I, the inhibition microorganisms were higher toward the end of growth stage than the early stage, but the result of farmhouse II was opposite. Effects of the mycelium growth on plate culture showed same results on mushrooms as the earlier one. And the mycelium growth was influenced by secretory materials of microorganisms. Among of the isolates, Only few microorganism had inhibitory effects on either P. tolaasii or T. harzianum causing the disease of oyster mushrooms. But more microorganisms had inhibition effects on P. agarici.

• Weed & Turfgrass Science
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• v.2 no.2
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• pp.202-206
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• 2013

Biocontrol potential of an isolate of Helicosporium spp. against Rhizoctonia solani, Fusarium oxysporium and Phytophthora drechsleri was evaluated in vitro and in vivo. A selected biocontrol agent designated as Helicosporium 0635BP strongly inhibited growth and lysed mycelium of Rhizoctonia solani and Fusarium oxysporium on PDA. Autoclaved culture filtrate of the agent also completely inhibited growth of the turfgrass large patch pathogen, R. solani AG2-2 IV at the concentration of 50 ml $L^{-1}$. The pathogen was killed when dipped under the 20% filtrate for four hours or 50% for one hr. In a field trial, plots applied with the crude or times diluted culture filtrate showed 100% control efficacy of the turfgrass large patch as a chemical applied for a comparison. Results indicated that Helicosporium 0635BP is a promising biocontrol agent on control of the turfgrass large patch disease and its culture filtrate contained unknown heat suitable antifungal substance (s). Further studies on mass production, purification and identification of the unknown compound (s) are in progress for practical use.

• Korean Journal of Clinical Laboratory Science
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• v.51 no.1
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• pp.15-25
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• 2019

The development of reliable and objective definitions as well as automated processes for the detection of health care-associated infections (HAIs) is crucial; however, transformation to an automated surveillance system remains a challenge. Early outbreak identification usually requires clinicians who can recognize abnormal events as well as ongoing disease surveillance to determine the baseline rate of cases. The system screens the laboratory information system (LIS) data daily to detect candidates for health care-associated bloodstream infection (HABSI) according to well-defined detection rules. The system detects and reserves professional autonomy by requiring further confirmation. In addition, web-based HABSI surveillance and classification systems use discrete data elements obtained from the LIS, and the LIS-provided data correlates strongly with the conventional infection-control personnel surveillance system. The system was timely, acceptable, useful, and sensitive according to the prevention guidelines. The surveillance system is useful because it can help health care professionals better understand when and where the transmission of a wide range of potential pathogens may be occurring in a hospital. A national plan is needed to strengthen the main structures in HAI prevention, Healthcare Associated Prevention and Control Committee (HAIPCC), sterilization service (SS), microbiology laboratories, and hand hygiene resources, considering their impact on HAI prevention.

• Journal of Applied Biological Chemistry
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• v.65 no.2
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• pp.101-105
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• 2022

Quercetin is a major flavonoid in onion and known to antimicrobial activity against several pathogenic bacteria. However, the antibacterial activity of quercetin had not been evaluated against plant pathogenic Xanthomonas campestris and Erwinia carotovora. In here, quercetin and the solvent extracts of onion were investigated their antibacterial activity. Quercetin showed a selective inhibitory activity against X. campestris, and the minimal inhibition concentration (MIC) and minimal bactericidal concentration of quercetin were 15.6 and 20.0 ㎍ mL^-1 respectively. Otherwise, it showed no inhibitory activity against E. carotovora, and no the additive and the synergistic effects with streptomycin on X. campestris. And the EtOAc extract from the peel of onion that contained quercetin showed 2-fold lower MIC (500 ㎍ mL^-1) than the EtOH extract, thus EtOAc was suggested as the extraction solvent for quercetin from onion peel.

• Korean Journal of Poultry Science
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• v.49 no.2
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• pp.69-77
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• 2022

Antimicrobial peptides (AMPs) play an important role in innate immunity against pathogenic infections. AMPs exterminate pathogenic bacteria by disrupting cell membranes or inhibiting intracellular molecules. NK-2, first identified in pigs and derived from NK-lysin, has antimicrobial effects against bacteria and parasites. In this study, chimeric peptides (cpNK) of chicken and pig NK-2 and cpNK-derived peptides (cpNK-a1 and cpNK-a2) were synthesized, and their antimicrobial effects against various pathogenic bacteria such as Escherichia coli, Salmonella spp., Listeria monocytogenes, Staphylococcus aureus, and methicillin-resistant Staphylococcus aureus (MRSA) were investigated. The structure of chimeric peptides from chicken and pig NK-2, cpNK, include α-helix like NK-2 and peptide net charge was +9 like porcine NK-2. The cpNK peptide showed powerful bactericidal effects against most bacterial species, including MRSA, especially against gram-negative bacteria. Furthermore, cpNK-derived short peptides, cpNK-a1 and a2 also showed bactericidal activity, but the effects were weaker than those of cpNK. Therefore, we conclude that cpNK- and cpNK-derived short peptides have the potential to be used as antibiotic alternatives.

• Journal of Life Science
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• v.34 no.10
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• pp.673-681
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• 2024

Periodontal disease is a significant oral health issue, with halitosis-inducing bacteria being one of its primary causes. Among these bacteria, the anaerobic pathogen Porphyromonas gingivalis is known to accelerate the progression of periodontitis. Effective control and prevention of these bacteria are therefore crucial for the management and prevention of periodontal diseases. The aim of this study was to explore methods for effectively controlling halitosis-causing bacteria to enhance oral hygiene and the prevention of halitosis. We focused on Dendropanax morbifera, a traditional Korean medicinal plant known for its antimicrobial, anti-inflammatory, and antioxidant properties. Specifically, we investigated the antimicrobial effects of D. morbifera leaf extracts and fermented sap against P. gingivalis. The minimum inhibitory concentrations (MICs) and minimum bactericidal concentrations (MBCs) of the leaf extracts and fermented sap were determined under anaerobic conditions. The efficacies in reducing malodor were also evaluated using detection tubes to measure by measuring the concentrations of hydrogen sulfide (H₂S) and ammonia (NH₃) using detection tubes. Both the extracts and sap exhibited significant antimicrobial activity against P. gingivalis. Furthermore, both test materials effectively reduced bacterial production of H₂S and NH₃ gases. Field emission scanning electron microscopy observations revealed that bacterial cell wall damage began at the MIC levels, with complete cell wall destruction observed at the MBC levels. These results provide valuable data regarding the antimicrobial and halitosis-reducing effects of D. morbifera leaf extracts and fermented sap and support the potential use of D. morbifera in developing new oral hygiene products.

• Journal of Mushroom
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• v.2 no.1
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• pp.4-9
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• 2004

This study was carried out to investigate effect of NaCl treatment on growth oyster mushroom and Trichoderma spp. on PDA and in rice straws. We also investigated the possibility of oyster mushroom cultivation using rice straw harvested from the reclaimed land having been drained sea water. Mycelial growth of oyster mushroom was increased by treatment of 0.2% NaCl but decreased by treatment of the higher concentration of NaCl. In the case of the mycelial growth on PDA of Trichoderma spp., no change was found in 0.5%~1.0% NaCl, but decreased in the range of 1.0%~3.0% NaCl and drastically decreased at 5.0% NaCl. In the rice straws treated with different concentration of NaCl solution, mycelial growth of oyster mushroom showed almost same result compare to PDA. The spore formation of Trichoderma mould was almost same in both 0% and 0.3% NaCl, decreased in 0.5% and was not found spores in the higher concentration of NaCl. As increasing salt concentration in the rice straws, the NaO contents were increased. The $K_2O$ contents were decreased before and after sterilization. The moisture content of rice straws showed no difference by treatment of 3.0% NaCl but decreased the moisture by treatment of 5.0% NaCl. No pH change was found in the rice straws treated with NaCl. Mushroom yield in the rice straw of reclaimed land was a little higher than that of normal paddy land straw. The duration of primordium formation was not affected by NaCl concentration in rice straws. The yield of fruiting body in 0.3% NaCl treatment was 2,700kg, which was almost same to non-treated plot, but decreased in 0.5% NaCl. EC value of soaking water after submerging rice straw was higher than before, but NaO content was not changed at both condition.