• Research in Plant Disease
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• v.25 no.1
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• pp.33-37
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• 2019

From 2016 to 2018, approximately 15% of kohlrabi were observed displaying significant clubroot symptoms in farmer's fields in Jeju, Korea. The initial infection appeared as hypertrophy of root hairs, and as the disease progressed, galls formation occurred on the main roots, finally disease progress resulted in yellowing and wilting of leaves. Pathogenicity was proven by artificial inoculation of plants with resting spore suspension, fulfilling Koch's postulates. The resting spore is one-celled, spherical and subspherical, colorless, and $3-5{\mu}m$ in diameter. On the basis of the morphological characteristics and phylogenetic analyses of internal transcribed spacer rDNA, the causal agent was identified as Plasmodiophora brassicae. To our knowledge, this is the first report on the occurrence of P. brassicae on kohlrabi in Korea.

• Microbiology and Biotechnology Letters
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• v.23 no.2
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• pp.243-248
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• 1995

Agrochemicals for the plant-disease control are criticized severely for causing environmental pollution and residual problems, and consequently microbial disease control agents are expected to be safer and more economical for sustainable agriculture. Treatment of biological control agents to seed requires the use of effective delivery systems that allow full expression of the benefical qualities of the bioprotectant. For the activation and establishment of bioprotectant around the plant seed which are able protect the seeds and seedlings from pathogen attack, the optimal liquid coating formulation was obtained using 2% sodium carboxymethyl cellulose (binder), 20% sesame dregs (solid particulate material), and dried spore of Bacillus subtilis YBL-7 (bioprotectants, 10 mg/g of seed). Suppressive of root rot was demonstrated in pot trials with coated kidney bean (Phaseolus vulgaris L.) seeds. Coated seeds with B. subtilis YBL-7 spore in F. solani-infested soil reduced disease incidence by 85% to 90% after 30 days.

• Environmental Engineering Research
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• v.19 no.1
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• pp.67-73
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• 2014

In India, disposal of vegetable market waste along with municipal solid waste in landfills or dumpsites is creating much nuisance in terms of odor nuisance, leachate production, and greenhouse gas emission into the atmosphere. Therefore, vegetable waste with high biodegradable and nutrient content is composted in a 550-L batch scale rotary drum composter to study the degradation process and its compost properties for its potential reuse as high quality compost. A total 150 kg of working volume was fixed for composting studies with two different ratios, trial A (6:3:1) of C/N 24 and trial B (8:1:1) of C/N 30, respectively. A maximum of $63.5^{\circ}C$ and $61.2^{\circ}C$ was observed in trials A and B; an average of $55^{\circ}C$ for more than 5 days, which helped in the degradation of organic matter and reduction of total and fecal coliform. The temperature dropped suddenly after the thermophilic stage in trial B, and leachate was observed due to insufficient amount of bulking agent. Mesophilic bacteria dominated during the initial stages of composting, and reduced considerably during the thermophilic stage. During the thermophilic stage, the rise in spore-forming organisms, including spore-forming bacteria, fungi, actinomycetes and streptomycetes, increased and these were predominant until the end of the composting process. By examination, it was observed that moisture and leachate production had adverse effects on the compost parameters with higher loss of micronutrients and heavy metals.

• Journal of Environmental Health Sciences
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• v.8 no.2
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• pp.47-51
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• 1982

135 Raw milk samples corrected from 4 dairy plants before processing were held at 63$\circ$C for 30 minutes and 80$\circ$C for 10 minutes. Thermoduric mesophiles, psychrotrophs and thermophilic bacteria were estimated from the samples treated at 63$\circ$C for 30 minutes and aerobic spore formers from the samples treated at 80$\circ$C for 10 minutes. The results obtained were as follows. 1) The distribution of thermoduric mesophiles were $10^4 - 10^5$ cfu/ml (45.2%), $10^2 - 10^4$ cfu/ml (21.5%), $10^5$ cfu/ml over (20.7%), $10^2 - 10^3$ cfu/ml (8.9%) and $10 - 10^2$ cfu/ml (3.7%). 2) The distribution of thermoduric psychrotrophs were 10 - $10^2$ cfu/ml (40.2%), $10^2 - 10^3$ cfu/ml (29.5%), 10 cfu/ml below (22.3%) and $10^3 - 10^4$ cfu/ml (8.0%). Isolated psychrotrophs had the characteristics of Streptococcus, Micrococcus and Alcaligenes group. 3) The distribution of thermophilic bacteria were 10 cfu/ml below (91.9%), and 10 - $10^2$ cfu/ml (81.8%). 4) Aerobic spore formers counts were 10 cfu/ml below (27.4%), $10^3 - 10^4$ cfu/Illl (26.5%), $10^2 - 10^3$ cfu/ml (23.9%)and 10 - $10^2$ cfu/ml (22.1%).

• Korean Journal of Environmental Agriculture
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• v.27 no.1
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• pp.80-85
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• 2008

This study was carried out to assess the antidermatophytic potential of the ethyl acetate(EtOAc) extract of the marine isolate of Aspergillus sp.. The fungus was isolated by serial dilution, and was identified Aspergillus sp.. The EtOAc extract of the fungus was examined to evaluate the antidermatophytic efficacy against the fungal pathogens infecting human skin using the disc diffusion and MIC(minimum inhibitory concentration) determination methods. The EtOAc extract($5{\mu}l\;disc^{-1}$) was considered to have the antidermatophytic activity based on the inhibition percentage of the mycelial growth of the fungi tested such as Trichophyton mentagrophytes KCTC 6085, Microsporum canis KCTC 6591, Microsporum canis KCTC 6348, Trichophyton rubrum KCTC 6352, Microsporum canis KCTC 6349 and Trichophyton mentagrophytes KCTC 6316. The percentage of the inhibition ranged from 54% to 81, and the MIC obtained was 62.5, 62.5, 250, 125, 125, and $125{\mu}g\;ml^{-1}$, respectively. The extract had a strong detrimental effect on the spore germination of the tested skin infectious pathogens. These findings strongly support the role of the ethyl acetate extract as a potential antidermatophytic agent.

• Journal of environmental and Sanitary engineering
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• v.14 no.4
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• pp.180-187
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• 1999

The following is experimental result of Biochemical characteristics of Acetobacter sp. Acetobacter sp. were gram negative, short rod, non-spore-forming and motile. It reacted positively catalase, methyl red, oxidation fementation, voges-proskauer and nitrate reduction tests and hydrogen sulfide test negative and ONPG negative. Acetobacter sp. showed normal growth curve in Carr broth and there was no significant difference between isolates and type strains such as Acetobacter aceti(KCTC 1010), Acetobacter diazotrophicus(KCTC 2859). Acetobacter liquefaciens(KCTC 2804) and Acetobacter pasteurianus(KCTC 1008).

• Mycobiology
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• v.48 no.6
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• pp.484-494
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• 2020

Oak wilt disease caused by Raffaelea quercus-mongolicae has emerged obviously in Korea. We selected antifungal isolates against R. quercus-mongolicae among 368 endophytic fungal isolates from different parts of oak and pine trees. The experiment was conducted in the primary and secondary screenings by dual culture test. The antifungal activity of the selected isolates was assessed in culture filtrate test based on the inhibition rates in mycelial growth, sporulation, and spore germination of oak wilt fungus. Five isolates, E089, E199, E282, E409 and E415, showed strong antifungal activity in culture filtrate test, and their antifungal activity decreased on the culture media supplemented with heated culture filtrate. Higher mycelial growth inhibitions on the unheated media were recorded in E409 (Colletotrichum acutatum), E089 (Daldinia childiae), E415 (Alternaria alternata) and E199 (Daldinia childiae) with the inhibition rates of 79.0%, 70.1%, 68.9% and 64.5%, respectively. These isolates also had the higher sporulation inhibitions on unheated media with the rates of 96.8%, 84.2%, 82.8% and 80.5%, respectively. The spore germination of the oak wilt fungus was completely inhibited by E282 (Nectria balsamea) on both unheated and heated media. These results showed that a higher number of potent antifungal isolates against oak wilt fungus was isolated from the petiole compared to the other parts. This study could contribute to the development of biological control approaches for the management of oak wilt disease caused by R. quercus-mongolicae.

• The Korean Journal of Pesticide Science
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• v.14 no.4
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• pp.401-406
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• 2010

This study was conducted to investigate the control effects of the environmental-friendly materials against major diseases of pear and to elucidate factors related to spore disperse of pear scab and pear rust. Spore disperse was deeply related ambient temperature in the early stage of disease occurrence and the maximum spore disperse was affected greatly by the air humidity, Percent of infected leaves of pear scab in plot treated with Trichoderma harzianum-YC459 was 29.3% and 43.3% in plot treated with Sulfur-80%. Two formulations above-mentioned were less effective to control pear scab than the chemical pesticide, hexaconazole. Control effect in plots single- and mixed-treated with Trichoderma harzianum-YC459, Sulfur-80% and hexaconazole against pear scab were compared with that in plot treated with chemicals by conventional application schedule in pear orchard. The incidence of pear scab was lower in plot treated with the environmental-friendly materials than that of untreated plot. However there was no significant difference among the treatments at the 5% level. Application of Sulfur-80% reduced significantly the incidence of pear scab (7.8%) compared to that (10.3%) in plot treated by conventional application schedule in organically cultivated pear orchard. Alternative application of Trichoderma harzianum-YC459 and Sulfur-80% (4.3%) suppressed the incidence of pear rust than that (7.1%) in plot treated by conventional application schedule in organically cultivated pear orchard.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.2
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• pp.1204-1210
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• 2014

New control methods are proposed for indoor air quality by removing fine airborne dust-particles. As suspended fine dust-particles contain inorganic dust as well as fine organic bacteria, studies for simultaneous control of these contaminants are required. In this study, photocatalytic disinfection of indoor suspended microorganisms such as E. coli and Bacillus subtilis is performed by three types of photocatalysts with UVA irradiation. The UVA irradiation strength was controlled to the minimum $3{\mu}W/cm^2$, and ZnO, $TiO_2$, and ZnO/Laponite ball were used as the catalysts. The results indicate that E. coli was removed over 80 % after about 2 hours of reaction with UVA and all three types of photocatalysts, whereas only with UVA, around 50 % E. coli removal was obtained. Among the catalysts, ZnO/Laponite composite ball was found to have similar sterilizing capacity to $TiO_2$. However, in case of B. subtilis, which has thick cell wall in its spore state, disinfection was not effective under the low UVA irradiation condition, even with the catalysts. Further studies need to figure out the optimal UVA irradiation ranges as well as photocatalysts doses to control airborne dust, to provide healthy clean air environment.

• Biotechnology and Bioprocess Engineering:BBE
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• v.7 no.1
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• pp.21-25
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• 2002

To maximize and sustain the productivity of Monascus pigments, various environmental and nutritional parameters, such as the initial moisture content, pH, inoculum size, sample size, and nutrient supplement, that influence pigment production were evaluated in solid-state cultures as follows: initial moisture content, $50\%;$ pH, 6.0; inoculum size $1\;\times\;10^4$ spore cells $(grams\;of\;dry\;solid\;substrate)^{-1};$ sample size, 300 g. All supplementary nutrients (carbon, nitrogen, and mineral sources) added has inhibitory effects on the cell growth and red pigment production. In open tray culture the maximum biomass yield and specific productivity of red pigments were 223 mg DCW $(grams\;of\;initial\;dry\;substrate)^{-1}$ and, $47.6\;OD_{500}\;(DCW\;grams)^{-1}h^h{-1}$ respectively.