• Journal of Veterinary Clinics
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• v.18 no.1
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• pp.55-60
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• 2001

Immunohistochemical and Electron Microscopical Studies on the Initial Skin Lesions Induced Experimentally by Very Virulent Strain of Marek\`s Disease Virus in Chickens Marek\`s disease virus (MDV), which is an avian herpesvirus, causes malignant CD3+CD4+CD8-T cell lymphomas at many sites including visceral organs, muscles, peripheral nerves and skin. In the early skin lesions induced by MDV, corelationship between the translational activity of MDV early gene, pp38 and demonstration of MDV particles in the lymphoid cells are not well studied. Therefore, skin biopsies taken at weekly intervals for 2 weeks from the same specific-pathogen free chicknes inoculated with Md/5 MDV were examined immunohistochemically and electron microscopically. In the skin biopsies sampled at 1 week and 2 weeks post inoculation (PI), feather follicle epithelium (FFE) exhibited usually strong positive reaction for pp38, whereas only few lymphoblasts, which were infiltrated around FFE revealed positive reaction. Electron microscopically, small lymphocytes were detectable in the dermis and subcutaneous skin tissues sampled at 1 week PI. The number of small lymphocytes was increased and pleomorphic lymphoblasts, which were medium to large in size were scattered among the small lymphocytes at 2 weeks PI. Some of lymphoblasts revealed degenerative and necrotic changes. FFE contained a lot of MDV particles in the nucleus including mature and immature ones. Infrequently, immature virus particles were observed not only in the degenerative and necrotic lymphoblasts, but also rarely in the health lymphoblasts. From the present results, spontaneous MDV activation including translational activity of MDV pp38 gene and formation of MDV particles was occurred in the lymphoblasts of early MD skin lesions.

• Journal of Microbiology and Biotechnology
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• v.19 no.5
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• pp.462-467
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• 2009

Cyclosporin A (CyA) produced by Tolypocladium inflatum is a promising drug owing to its immunosuppressive and antifungal activities. From an industrial point of view, the necessity to obtain a suitable and economic medium for higher production of CyA was the aim of this work. The present study evaluated the effect of different fermentation parameters in solid state fermentation, such as selection of solid substrate, hydrolysis of substrates, initial moisture content, supplementation of salts, additional carbon, and nitrogen sources, as well as the inoculum age and size, on production of CyA by Tolypocladium inflatum MTCC 557. The fermentation was carried out at $25{\pm}2^{\circ}C$ for 9 days. A combination of hydrolyzed wheat bran flour and coconut oil cake (1:1) at 70% initial moisture content supported a maximum production of $3,872{\pm}156\;mg$ CyA/kg substrate as compared with $792{\pm}33\;mg/kg$ substrate before optimization. Furthermore, supplementation of salts, glycerol (1% w/w), and ammonium sulfate (1% w/w) increased the production of CyA to $5,454{\pm}75\;mg/kg$ substrate. Inoculation of 5 g of solid substrate with 6 ml of 72-h-old seed culture resulted in a maximum production of $6,480{\pm}95\;mg$ CyA/kg substrate.

• Journal of Microbiology and Biotechnology
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• v.11 no.4
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• pp.607-613
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• 2001

The biodegradation rates of diesel oil by a selected diesel-degrading bacterium, Pseudomonas stutzeri strain Y2G1, and microbial consortia composed of combinations of 5 selected diesel-degrading bacterial were determined in liquid and soil systems. The diesel degradation rate by strain Y2G1 linearly increased $(R^2=0.98)$ as the diesel concentration increased up to 12%, and a degradation rate as high as 5.64 g/l/day was obtained. The diesel degradation by strain Y2G1 was significantly affected by several environmental factors, and the optimal conditions for pH, temperature, and moisture content were at pH8, $25^{\circ}C$, and 10%, respectively. In the batch soil microcosm tests, inoculation, especially in the form of a consortium, and the addition of nutrients both significantly enhanced the diesel degradation by a factor of 1.5 and 4, respectively. Aeration of the soil columns effectively accelerated the diesel degradation, and the initial degradation rate was obviously stimulated with the addition of inorganic nutrients. Based on these results, it was concluded that the major rate-limiting factors in the tested diesel-contaminated soil were the presence of inorganic nutrients, oxygen, and diesel-degrading microorganisms. To resolve these limiting parameters, bioremediation strategies were specifically designed for the tested soil, and the successful mitigation of the limiting parameters resulted in an enhancement of the bioremediation efficiency by a factor of 11.

• The Plant Pathology Journal
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• v.34 no.1
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• pp.1-10
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• 2018

A previously unreported bacterial disease on chili pepper (Capsicum annuum L.) seedlings affecting as many as 4% of seedlings was observed in greenhouses in Chihuahua, Mexico (Delicias and Meoqui counties). Initial lesions appeared as irregular small spots on leaves and brown necrosis at margins tips were observed. Later, the spots became necrotic with a chlorotic halo. Advanced disease was associated with defoliation. A Gram negative, rod-shaped bacterium was isolated from diseased chili pepper seedlings. Three inoculation methods revealed that isolated strains produce foliage symptoms, similar to those observed in naturally infected seedlings. Pathogenic strains that caused symptoms in inoculated seedlings were re-isolated and identified to fulfill koch's postulate. Polyphasic approaches for identification including biochemical assays (API 20E and 50CH), carbon source utilization profiling (Biolog) and 16S rDNA, hsp60 and rpoB sequence analysis were done. Enterobacter cloacae was identified as the causal agent of this outbreak on chili pepper seedlings.

• Korean Journal Plant Pathology
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• v.11 no.3
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• pp.282-284
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• 1995

Grey leaf spot on tomato plants was first observed in Sedo-myeon, Puyo-kun, Chungnam province of Korea in 1994. This disease which had not been reported before in Korea exhibited different symptoms from those of other leaf spot diseases on tomato plants. The symptoms were characterized by small irregular-shaped spots on leaves at the initial stage of the infection, subsequent spread and coalescence of the spots throughout the leaves with ultimate necrosis, and abscission from the plants. When healthy tomato plants were inoculated with a conidial suspension of the fungus isolated from the lesion of a diseased plant in a field, the same characteristic symptoms as those in the field were produced. Furthermore, the same pathogen could be reisolated from the lesions formed buy the inoculation. Conidial characteristics of the pathogen were as follows; oblong shape with constricted 3 transverse septa, round-shaped base, round- or point-shaped apex, size of 45~75$\times$12.5~17.5 ${\mu}{\textrm}{m}$, and 3.5 : 1 ratio of length to width. The pathogen was identified as Stemphylium lycopersici and thus this is the first report on the occurrence of grey leaf spot disease on tomato plants caused by s. lycopersici in Korea.

• Journal of the Korean Geotechnical Society
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• v.15 no.6
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• pp.273-283
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• 1999

When microorganism is injected into porous medium such as soils, biomass is retained in the pore. Soil pore size and shape are varied from the initial condition as a result of biofilm formation which makes hydraulic conductivity reduced and friction rate between soil aggregates increased. In this research, hydraulic conductivity reduction was measured after microorganism are inoculated and cultured with synthetic substrate and nutrient. In addition, this research evaluated the applicability of biomass-soil mixture to the field condition as an alternative cover material in landfill by measuring hydraulic conductivity change after repetitive freeze-thaw cycles. Hydraulic conductivity of silty soil decreased by approximately 1/50 after biomass inoculation and cultivation. Biofilm attached on soil aggregates is resistant to acidic or basic condition. After repetitive freeze-thaw cycles, however, hydraulic conductivity increase implies that biomass clogging can be impaired.

• The Plant Pathology Journal
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• v.26 no.1
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• pp.80-82
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• 2010

A stem spot disease was observed on Gymnocalycium mihanovichii (Korean name: Bimoran), a scion of graftcactus, in major growing areas of Goyang and Eumseong, Korea during 2008 and 2009. Typical symptoms were initial blackish brown lesions produced mainly on areoles and scars of injured stem tissues, gradually becoming large black spots. A causal organism isolate CD2-7A isolated from the infected stems was identified as Alternaria alternata based on its morphological characteristics and confirmed by the DNA sequencing analysis of ITS, glyceraldehydes-3-phosphate dehydrogenase (gpd), and allergen Alt a1 (Alt a 1) genes. Artificial inoculation of the fungal isolate CD2-7A produced the same rot symptoms on the cactus stems, from which the same fungus was isolated and identified. This is the first report of the black spot caused by A. alternata in the grafted cactus.

• Journal of Microbiology and Biotechnology
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• v.16 no.8
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• pp.1301-1305
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• 2006

The development of rapid, infallible, and sensitive methods of detecting foodborne pathogens has received much impetus in recent years owing to an increased public awareness of the health hazards. For the rapid and simultaneous detection of these foodborne pathogens, a multiplex PCR method was developed. Yersinia enterocolitica, Staphylococcus aureus, and Shigella spp. are bacteria of concern because of their specific growing condition that enables them to live at low temperatures. In order to detect each pathogenic bacterium, specific primers from Y. enterocolitica, St. aureus, and Sh. flexneri were selected and validated successfully. To apply this method to food stored at low temperature, Y. enterocolitica, St. aureus, and Sh. flexneri were artificially inoculated in lettuce and incubated for enrichment. The multiplex PCR assays were able to simultaneously detect three pathogens, and the presence of three bands was observed at initial inoculation levels of approximately 1$\times$10$^1$ CFU/g in lettuce. Therefore, this method could be used for simultaneous detection of Y. enterocolitica, St. aureus, and Shigella spp. contaminated in lettuce during cultivation, transportation, preservation, and storage.

• Journal of Microbiology and Biotechnology
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• v.13 no.1
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• pp.1-8
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• 2003

Strain FJI, a filamentous fungus isolated from rotten wood, showed high ability to hydrolyze cellulosic materials. To identify the strain FJI, ITS sequencing analysis and morphological observation were performed. The strain FJI was identified as Trichoderma harzianum. The strain produced a large amount of CMCase, xylanase, ${\beta}-glucosidase$, and avicelase. Optimal culture conditions for the production of the enzymes, such as pH, temperature, and inoculation concentration, were initial pH 6.0-7.0,$25-30^{\circ}C$, and $10^4$ ea-spores/ml in Mandel's medium, respectively. T.hanzianum FJI utilized various cellulosic materials and organic nitrogen sources to produce cellulases and xylanase, and also considerably a crystalline and/or insoluble material like Avicel and rice straw. The highest levels of CMCase and xylanase were 41.2 and 65.6 U/ml in 7 days of cultivation using 2.5% of carbon source (Avicel+CMC) and 0.5% of nitrogen source (peptone), respectively.

• KSBB Journal
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• v.26 no.1
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• pp.57-61
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• 2011

The principal objective of this study was to determine the optimal conditions for the production of biosurfactant by the indigenous bacterium, Pseudoalteromonas sp. HK-3, originating from oil-spilled areas. The relationship between total biosurfactant production and the factors affecting biosurfactant production were evaluated by statistical analysis using SPSS software. The effects of various supplemental carbon sources (e.g., glucose, dextrose, mannitol, citrate, acetate) on the maximal production of biosurfactant by the test culture of Pseudoalteromonas sp. HK-3 was then evaluated. As a result, mannitol was found in this study to be the best supplemental carbon source for the production of biosurfactant. A spot inoculation of crude cultural liquid containing the HK-3 cells generated the largest clear zone, whereas only small clear zones appeared around the spots inoculated with either supernatant only or cell pellets following centrifugation. Our results demonstrated that the HK-3 test culture supplemented with 2% mannitol at an initial pH of 6 generated the maximal amount of biosurfactant within 72 h of incubation.