• Korean Journal of Soil Science and Fertilizer
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• v.33 no.4
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• pp.261-265
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• 2000

To develope the enhanced bacterial strains capable of biodegradation for various chlorinated aromatic compounds, 100 bacterial strains were isolated from soil samples of suburbs of Taejon, Cheongju, and Jeonju by the enrichment culture. These strains can degrade pentachlorophenol (PCP) which is a kind of wood preservatives. Nineteen strains of the isolates were selected by fast colony-forming rate on solid minimal media containing PCP as an only source of carbon and energy. These strains were identified to genus level. Fifteen strains were identified as Pseudomonas, 1 strain as Acinetobacter and 3 strains were not. Genus Alcaligenes strains were not found among them. Pseudomonas sp. MU135. MU139, MU163 and MU 184 were able to degrade for 4 kinds of chlorinated compounds, PCP, 2,4-D, MCPA and 3CB. Pseudomonas sp. If was observed that MU139 exhibits the highest degradability in liquid minimal media at 72 hours after inoculation. Pseudomoans sp. MU147, MU177, MU184 and MU192 also degraded the compounds at higher rates. As the results, Pseudomonas sp. MU139 and unidentified strain MU184 had biodegrability for broad range of chlorinated compounds and higher rates of degradation for PCP.

• Korean Journal of Poultry Science
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• v.44 no.3
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• pp.181-188
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• 2017

Bacteriophages are viruses that exclusively infect bacterial cells, and lytic bacteriophages can be used as a safe alternative to antibiotics for the prevention and treatment of animal diseases. In this study, we attempted to isolate and characterize bacteriophages for Salmonella enterica serovar Gallinarum (Salmonella Gallinarum), the causative agent of fowl typhoid in chickens. Ten bacteriophages were isolated from samples of sewage from seven poultry slaughterhouses. One of these isolate, designated as $SG{\Phi}-YS$ SP and classified in the family Myoviridae, produced plaques with seven Salmonella Gallinarum strains. However, no plaques were produced with any of the Salmonella enterica serovar Enteritidis strains tested, suggesting that this bacteriophage is Salmonella Gallinarum specific. To assess the lytic ability of $SG{\Phi}-YS$ SP against Salmonella Gallinarum, bacterial growth rates following inoculation of the bacteriophage were compared with the control. The $SG{\Phi}-YS$ SP treatment, with a multiplicity of infection of 10, reduced the growth of Salmonella Gallinarum by 2.21 log cfu/mL at 6 h, and 2.13 log cfu/mL at 9 h, suggesting that this bacteriophage isolate could be used for the prevention or treatment of Salmonella Gallinarum infection in chickens.

• 한국균학회소식:학술대회논문집
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• 2016.05a
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• pp.25-25
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• 2016

Biological control has many advantages as a disease control method, particularly when compared with pesticides. One of the most important benefits is that biological control is an environmental friendly method and does not introduce pollutants into the environment. Another great advantage of this method is its selectivity. Selectivity is the important factor regarding the balance of agricultural ecosystems because a great damage to non target species can lead to the restriction of natural enemies' populations. The objective of this research was to evaluate the effects of several different bacterial isolates on the efficacy of biological control of soil borne diseases. White rot caused by Sclerotium cepivorum was reported to be severe disease of garlic and chive. The antifungal bacteria Burkholderia pyrrocinia CAB08106-4 was tested in field bioassays for its ability to suppress white rot disease. In field tests, B. pyrrocinia CAB08106-4 isolates suppressed white rot in garlic and chive, with the average control efficacies of 69.6% and 58.9%, respectively. In addition, when a culture filtrate of B. pyrrocinia CAB08106-4 was sprayed onto wounded garlic bulbs after inoculation with a Penicillium hirstum spore suspension in a cold storage room ($-2^{\circ}C$), blue mold disease on garlic bulbs was suppressed, with a control efficacy of 79.2%. These results suggested that B. pyrrocinia CAB08106-4 isolates could be used as effective biological control agents against both soil-borne and post-harvest diseases of Liliaceae. Chinese cabbage clubroot caused by Plasmodiophora brassicae was found to be highly virulent in Chinese cabbage, turnips, and cabbage. In this study, the endophytic bacterium Flavobacterium hercynium EPB-C313, which was isolated from Chinese cabbage tissues, was investigated for its antimicrobial activity by inactivating resting spores and its control effects on clubroot disease using bioassays. The bacterial cells, culture solutions, and culture filtrates of F. hercynium EPB-C313 inactivated the resting spores of P. brassicae, with the control efficacies of 90.4%, 36.8%, and 26.0%, respectively. Complex treatments greatly enhanced the control efficacy by 63.7% in a field of 50% diseased plants by incorporating pellets containing organic matter and F. hercynium EPB-C313 in soil, drenching seedlings with a culture solution of F. hercynium EPB-C313, and drenching soil for 10 days after planting. Soft rot caused by Pectobacterium carotovorum subsp. carotovorum was reported to be severe disease to Chinese cabbage in spring seasons. The antifungal bacterium, Bacillus sp. CAB12243-2 suppresses the soft rot disease on Chinese cabbage with 73.0% control efficacy in greenhouse assay. This isolate will increase the utilization of rhizobacteria species as biocontrol agents against soft rot disease of vegetable crops. Sclerotinia rot caused by Sclerotinia sclerotiorum has been reported on lettuce during winter. An antifungal isolate of Pseudomonas corrugata CAB07024-3 was tested in field bioassays for its ability to suppress scleritinia rot. This antagonistic microorganism showed four-year average effects of 63.1% of the control in the same field. Furthermore, P. corrugata CAB07024-3 has a wide antifungal spectrum against plant pathogens, including Sclerotinia sclerotiorum, Sclerotium cepivorum, Botrytis cinerea, Colletotrichum gloeosporioides, Phytophotra capsici, and Pythium myriotylum.

• The Korean Journal of Mycology
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• v.37 no.2
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• pp.144-149
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• 2009

The occurrences of the major diseases and the densities of air-born microbes were surveyed in the cultivation facilities for oyster mushroom (Pleurotus ostreatus), king oyster mushroom (Pleurotus eryngii), and enoki mushroom (Flammulina velutipes) in different areas of Korea. Green mold disease was most often developed in oyster mushroom bed cultivation with the disease incidence rate of approximate 10% while the disease incidences from bottle and plastic envelop cultivation were less than 1~2%. In the bed cultivation, the major air-born microbes in the growth room were Aspergillus, Penicillium, Trichoderma, and Curvularia with the total fungal population density of 567~1,297 CFU/$m^3$ . However, only Trichoderma and Penicillium were detected in the growth rooms and innoculation rooms of bottle and plastic envelop cultivation with the densities of 350~700 CFU/$m^3$ and 160~260 CFU/$m^3$, respectively. The bacterial diseases become evident in the growth rooms of bottle and plastic envelop cultivation with the approximate incidence rate of 10%. The identified bacterial species were Brevibacillus levelkil, Rhizobium radiobacter, Brevundimonas vesicularis, Pseudomonas mosselii, Microbacterium testaceum. Sphingomonas panmi, Sphingomonas yabuuchiae, Paracocus dinitrificans, Curtobacterium flaccumfaciens pv. flaccumfaciens and some unidentified bacteria with the densities of 40~6,359 CFU/$m^3$ in the growth rooms and 9 CFU/$m^3$ in the inoculation room. This study indicated that the green mold disease by fungal strains was the major mushroom disease in the bed cultivation and suggested that the contamination of bacteria and fungi together in the growth media could result in severe production loss. The plastic envelope and bottle cultivation were evidenced to be less susceptible to such contaminations.

• Applied Biological Chemistry
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• v.22 no.2
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• pp.101-108
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• 1979

The viscosity of mucilage of Abelmoschus Manihot, Medic root decreased by the influence of various mechanical, physical and chemical conditions. It was experimented by viscosity decrease of mucilage connected with hydrogen ion concentration, bacterial multiplication, disinfection with 70% ethanol, some antibiotics, such as streptomycin, penicillin, ganamycin and chloramphenicol and mucilage derived from autoclaved Abelmoschus Manihot, Medic root. The results obtained were as follows: 1. It was clear that the viscosify of mucilage decreased notably under the influence of infected bacteria and bacterial multiplication. 2. By the inoculation of Bacillus subtilis ATCC 6633 and Escherichia coli ML 1410 to the mucilage the viscosify decrease fast but the viscosity of mucilage derived from autoclaved, Abelmoschus Manihot, Medic root. 3. The small quantity of reducing sugar in the mucilage was detected. 4. Hydrogan ion concentration in the mucilage remained $6.5{\sim}8.0$ in spite of the viscosity decrease.

• Journal of Veterinary Clinics
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• v.15 no.1
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• pp.62-74
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• 1998

In feedlot cattle the abrupt change of diet from roughage to a large quantity of grain for the purpose to improve production often results in increased occurrence of rumen acidosis or acute carbohydrate encouragement enterotoxemia, bloats diarrhea liver abscess and laminitis or robot disease. The common management practice to control these problem is to increase the amount of concentrates in the diet in a stepwise manner until the animals are adapted to a high-grain ration. However this practice requires at least about 3 weeks adaptation period and specially prepared adaptation rations which contain various amount of concentrates. Present experiment was undertaken in order to findout the more simple and rapid adaptation method of cattle to a high grain ration. Nineteen Korean calves aging from four to six month were fed artifical hay (Youngchoun Chuk-Hyup, Korea) which contains 10% of concentrates or alfalfa and rye grass hays for two months and randomly alloted to three experimental groups and two control groups. The experimental group-1 was inoculated by stomach tube for two days with li500 ml/day of ruminal fluid fished from Korean beef cattle that had been previously adapted to a high-energy ration. The experimental group-2 was inoculated by trocalization for two days with the same ruminal fluid. The experimental group-3 was inoculated by trocalization with 1,500 ml/day of bacterial culture which contained 2$\times $10$^{9}$/m1 of Gram-negative bacteria derived from adapted luminal fluid. The two control groups were treated with normal saline solution by the same methods. All animals were fed high-energy ration that contained 80% of grain ad libitum for 30-74 days beginning on the third of the treatment. The effect of the inoculation on the adaptation was observed clinicopathologically with the following results; All of the experimental calves inoculated with the ruminal fluid or Gram-negative bacterial culture derived from adapted cattle did not show any signs of rumen acidosis or other related diseases, while most of the control calves did show diarrhea and bloat and a calf laminitis. The average daily weight gain and feed efficiency of experimental calves were slightly improved compared with control calves. Following the feeding of high-grain rational the pH of the ruminal fluid was lowered in both the experimental and control groups. However severe acidosis with the pH of below 5.0 was observed in only a control group-2. The protozoal number in ruminal fluid was markedly decreased during the high-grain feeding in both the experimental and control calves. However the decrease was mere severe in control calves compared with the experimental calves. The activation of the protozoa were completely disappeared within nine hours at the refrigerator temperature (4"C). No significant differences in heamatological and blood chemical values between the experimental and control calves were recognized. However in one control calf which showed clinically laminitis marked elevations of serum glutamic oxaloacetate transaminase and lactic dehydrogenase activities and a decrease of serum glucose level were observed. From these results it would be concluded the intraruminal transplantation of unadapted calves with the adapted ruminal fluid from cattle previously adapted to a high-energy ration prevents disease problem associated with high-grain feeding and improve weight gain and feed efficiency.ency.

• Asian-Australasian Journal of Animal Sciences
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• v.32 no.12
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• pp.1873-1881
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• 2019

Objective: Information regarding the vitamin content of silage is limited. This study investigated the changes in the vitamin content of alfalfa and Chinese leymus silages with or without a lactic acid bacterial inoculant. Methods: Alfalfa at the early flowering stage and Chinese leymus at the full-bloom stage were harvested. The treatments for each forage type were control (deionized water only) and $1{\times}10^6$ colony-forming units Lactobacillus plantarum (LP)/g fresh matter. After 45 days of ensiling, all silages were sampled for evaluating the vitamin content, fermentation quality and chemical composition. Results: The LP inoculant decreased the pH value and ammonia nitrogen content of the alfalfa and Chinese leymus silages and significantly (p<0.05) increased the lactic acid, acetic acid concentrations and Flieg's points. Prior to ensiling, the levels of five B-group vitamins (thiamin, riboflavin, niacin, pantothenic acid, and pyridoxine) and ${\alpha}$-tocopherol in alfalfa were significantly (p<0.01) higher than those in Chinese leymus. Ensiling decreased the levels of the five B-group vitamins in both alfalfa and Chinese leymus while increasing the ${\alpha}$-tocopherol content of Chinese leymus. The thiamin, riboflavin, niacin and pantothenic acid levels in the LP-treated silage were significantly (p<0.05) lower than those in the untreated silage for the alfalfa and Chinese leymus. The ${\alpha}$-tocopherol content in the LP-treated alfalfa silage was significantly (p<0.05) higher than that in the untreated alfalfa silage. There was no significant (p>0.05) difference in pyridoxine content between the untreated and LP-treated silages for both forages. Conclusion: With or without LP inoculation, the levels of the five B-group vitamins (thiamin, riboflavin, niacin, pantothenic acid, and pyridoxine) in alfalfa and Chinese leymus decreased after 45 days of ensiling, while the ${\alpha}$-tocopherol content of Chinese leymus increased. The LP inoculant improved the fermentation quality of both the alfalfa and Chinese leymus silages but increased the thiamin, riboflavin, niacin, and pantothenic acid loss in the two forages after fermentation.

• Research in Plant Disease
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• v.24 no.4
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• pp.328-331
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• 2018

A severe disease with leaf spots and necrotic symptoms was observed in cucumber (Cucumis sativus L.) seedlings in April 2018 at a nursery in Kimjae, Korea (35o 47'09.8"N 127o 2'24.3"E). The infected plants initially showed spots on water-soaked cotyledons which, at later stages, enlarged and spread to the leaves, which the lesions becoming dry and chlorotic. The symptomatic samples were collected from cucumber and the isolates were cultured on LB agar. The representative bacterial strain selected for identification showed fluorescent on King's medium B, was potato rot-positive, levan and arginine dihydrolase-negative, oxidase-negative and tobacco hypersensitivity-positive in LOPAT group 2 as determined by LOPAT tests. A pathogenicity test was carried out on a 3-week-old cucumber. After 3 days of inoculation, leaf spots and necrotic symptoms appeared on the cucumber, similar to the originally infected plants. The infecting bacterial strain was identified as Pseudomonas viridiflava, by 16S rDNA sequence analysis. This is the first report of leaf spot diseases on cucumber caused by P. viridiflava.

• Proceedings of the Korean Society of Plant Pathology Conference
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• 2003.10a
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• pp.72.2-73
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• 2003

We found a soybean (Glycine max) cultivar 561 that was strongly resistant to a virulent bacterial strain of a Pseudomonas spp. Further identification revealed that the Pseudomonas spp. was a strain of Pseudomonas aeruginosa. Furthermore we identified specific genes involved in the resistance of soybean 561 and analyzed the pattern of gene expression against the Pseudomonas infection using differential-display reverse transcription PCR (DDRT-PCR). More than 126 cDNA fragments representing mRNAs were induced within 48 hours of bacteria inoculation. Among them, 28 cDNA fragments were cloned and sequenced. Twelve differentially displayed clones with open reading frames had unknown functions. Sixteen selected cDNA clones were homologous to known genes in the other organisms. Some of the identified cDNAs were pathogenesis-related genes (PR genes) and PR-like genes. These cDNAs included a putative calmodulin-binding protein, an endo-1,3-1,4-b-D-glucanase, a b-1,3-endoglucanase, a b-1,3-exoglucanase, a phytochelatin synthetase-like gene, a thiol pretense, a cycloartenol synthase, and a putative receptor-like sorineithreonine protein kinase. Among them, we found that four genes were putative pathogenesis-related genes (PR) induced significantly by the p. aeruginosa infection. These included a calmodulin-binding protein gene, a b-1,3-endoglucanase gene, a receptor-like sorine/threonine protein kinase gene, and pS321 (unknown function). These results suggest that the differentially expressed genes may mediate the strong resistance of soybean 561 to Pseudomonas aeruoginosa.

• Proceedings of the Korean Society of Plant Pathology Conference
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• 2003.10a
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• pp.120.3-121
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• 2003

Relative degree of resistance of citrus to Xanthomonas axonopodis pv. citri, the causal bacterium of canker, was investigated. Growth rate of a bacterium in leaf tissues after infiltration, disease incidence, and percent of lesion area were compared. By using growth rate[(GR=(At - A$\sub$t-1/)/A$\sub$t-1] host plants were differentiated into susceptible and resistant. Growth rates reached to peak at 40 hrs after inoculation and then declined. The growth rate in leaf tissues of a moderately susceptible cultivar, Citrus sinensis vu. Lane late(sweet orange), was the highest, and those of C. unshiu ${\times}$ C. sinensis(kiyomi), C. junos(yuzu), [(Citrus. unshiu x C. sinensis) x C. reticulata] (shiranuhi), and C. unshiu(satuma mandarin) were similar. This result indicates that the growth rate of the bacterium in leaf tissues can be effectively used for evaluation of disease resistance for citrus plants to X. axonopodis pv. citri. The disease on sweet orange occurred earlier than relatively resistant citrus plants tested. The percent of lesion area on leaf was also higher in sweet orange than those of satsuma mandarin, shiranuhi and kiyomi, and yuzu. The disease severity was highest on sweet orange and followed by kiyomi, shiranuhi, satsuma mandarin, and yuzu.