• 한국식품과학회지
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• 제29권1호
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• pp.133-137
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• 1997

대두침출액중의 비소화성 올리고당인 라피노스나 스타키오스함량에는 영향을 주지 않으면서 수크로스함량을 낮추기 위한 효모는 균주의 선택적 당이용 능력을 기준으로 선발하였다. 14종의 대상균주 중 스타키오스 이용율이 낮았던 Saccharomyces cerevisiae(ATCC 9763, KCTC 7039)와 Hansenula anomala KFRI 626이 적합하였다. 일정량의 대두침출액에 선정된 3종의 효모배양액을 각각 첨가하여 발효시간에 따른 올리고당 함량의 변화를 조사한 결과, 균주간에 차이는 있었으나, 전반적으로 균주 첨가량과 발효시간이 증가함에 따라 각 올리고당 함량이 감소경향을 보였다. 또 이들 3균주의 첨가량을 2%로 고정하고 발효 시간을 연장하여 당함량을 조사한 결과 수크로스 제거에 적당한 균주는 S. cerevisiae KCTC 7039와 H. anomala KFRI 626이었다.

• 환경생물
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• 제21권3호
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• pp.292-296
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• 2003

균귄 곰팡이(arbuscular mycorrhizal fungus, AMF)의 하나인 Glomus manihot을 이용하여 고추의 성장과 무기이온 흡수 및 고추의 치명적 질병인 역병 방제에 미치는 효과를 조사한 결과 매우 유의적인 결과를 얻을 수 있었다. AMF 균주 처리에 의해 질소, 인산, 칼리의 흡수와 초기 중량이 증가되었음을 파종 2주만에 확인할 수 있었으며 고추 품종에 따른 차이는 크게 나타나지 않았다. 이는 Glomus manihot이 고추의 발아와 동시에 부리에 공생하게 되어 나타나는 결과였으며 따라서 파종 시기에 맞춰 AMF를 투입하는 것이 중용한 것으로 판단된다. 야외에서 6주간 경작한 결과, 중량은 AMF와 불용성 인산을 동시에 처리한 결과 40％ 가까운 증가 효과를 나타내었다. 이러한 결과는 불용성 인산을 사용 가능케 하는 AMF의 특징에 의한 것으로 토양 내 문제점이 되고 있는 인산 과용에 의한 불용성 인산염의 제거에도 매우 좋은 효과를 나타내리라 판단되었다. 또한 Phyto-phtohra capsici에 의한 고추 역병에 대해서도 Glomus manihot의 접종이 그 피해를 경감시킬 수 있는 것으로 나타났다. 따라서 고추 품종에 상관없이 파종 초기에 Glomus manihot을 접종한다면 고추의 성장과 질병 방제효과를 통해 보다 좋은 품질의 고추를 생산할 수 있을 것으로 판단되었다.

• Biotechnology and Bioprocess Engineering:BBE
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• 제10권1호
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• pp.60-66
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• 2005

This study was performed to know whether there is any change of physiological activity in DLMJ which is inoculated by lactic acid bacteria. Lactic acid bacteria were isolated from Dolsan leaf mustard Kimchi (DLMK) at $20^{\circ}C$. In the optimum ripening period, the population of Leuconostoc and Lactobacilli in the DLMK were found to be high. The Leuconostoc, Lactobacilli and Lactococci strains were identified as Leuconostoc mesenteroides, Leuconostoc gelidum, Weissella confusa, Lactobacillus plantarum, Lactobacillus raffinolactis, Lactococcus lactis and Weissella confusa using the Biolog system. The most predominant strain which was isolated from DLMK was Weissella confusa. As the results of the phylogenetic analysis using 16s rDNA sequence, the Weissella confusa turned out to be Weissella kimchii, with 99.0% similarity. To investigated the change of physiological activity in DLMJ by lactic acid bacteria, 7 predominant strains inoculated to DLMJ (Dolsan Leaf Mustard Juice). The cytotoxicity was found to be under $19.55\%$ all cases. Also, the antioxidative activity of the DLMJ treated with lactic acid bacteria was very low, which might have been due to the reduced antioxidative phytochemicals during the preparation of the sterile sample. The ACE inhibiting activity of DLMJ by inoculation with Weissella kimchii was shown to be the highest ($94.0\%$). This could be that the degradation of sulfur containing materials in DLMJ by Weissella kimchii gave rise to ACE inhibiting activity.

• The Plant Pathology Journal
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• 제36권2호
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• pp.148-156
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• 2020

Pseudomonas syringae pv. tabaci 6605 has two multidrug resistance (MDR) efflux pump transporters, MexAB-OprM and MexEF-OprN. To understand the role of these MDR efflux pumps in virulence, we generated deletion mutants, ΔmexB, ΔmexF, and ΔmexBΔmexF, and investigated their sensitivity to plant-derived antimicrobial compounds, antibiotics, and virulence. Growth inhibition assays with KB soft agar plate showed that growth of the wild-type (WT) was inhibited by 5 μl of 1 M catechol and 1 M coumarin but not by other plant-derived potential antimicrobial compounds tested including phytoalexins. The sensitivity to these compounds tended to increase in ΔmexB and ΔmexBΔmexF mutants. The ΔmexBΔmexF mutant was also sensitive to 2 M acetovanillone. The mexAB-oprM was constitutively expressed, and activated in the ΔmexF and ΔmexBΔmexF mutant strains. The swarming and swimming motilities were impaired in ΔmexF and ΔmexBΔmexF mutants. The flood inoculation test indicated that bacterial populations in all mutant strains were significantly lower than that of WT, although all mutants and WT caused similar disease symptoms. These results indicate that MexAB-OprM extrudes plant-derived catechol, acetovanillone, or coumarin, and contributes to bacterial virulence. Furthermore, MexAB-OprM and MexEF-OprN complemented each other's functions to some extent.

• 한국동물위생학회지
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• 제13권2호
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• pp.162-183
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• 1990

From 1988 to 1989, 8 strains of canine parvovirus-2 (CPV-2) were isolated from the fecal specimens from the dogs that were clinically diagnosed as canine parvoviral enteritis in the veterinary hospitals located in the regions of Taejon and Chungbuk province. Studios on biological and physicochemical properties for the isolates were carried out. The results obtained by experiments are summarized as follows. 1. Among 62 fecal samples collected from the dogs with enteric diseases, 24 (38.7%) showed the haemagglutinating activity against porcine erythrocyte, ranging from 16 to 16, 384 of HA titers. 2. When 8 fecal specimens with high HA titer over 1, 000 were inocultated into CRFX cells, intranuclear inclusion bodies were obseverd in all of eight specimens, of w)lick three specimens showed cytoplasmic inclusions concurrently with the intranuclear inclusion bodies. 3. In study on species-specificity of haemagglutinating activity of the isolates, TJ-89-1 and TJ-89-2, it was found that the isolates revealed the highest haemagglutinating activity with porcine erythrocytes, showing the relatively lower haemagglutination titers with the erythrocytes from cat and rabbit. None of erythrocytes from other animals reacted with the isolates. 4. By the cross-haemagglutination inhibition test of the Isolates with reference viruses and sera, the Isolates were evidently identified as the strains of canine parvovirus-2. 5. In Physicochemical property test, it was evident that the isolates were stable in, lipid solvent, pH and heat treatment at $56^{\circ}C$ for 30 min. and contain DNA genome. 6. When seven puppies were inoculated intraorally with the isolate at HA titer of 8, 192, all of the puppies showed the symptoms of anorexia, vomiting, diarrhea and died at the 5th to 10th days post inoculation(pi). The fecal samples from all of the puppies revealed significantly high HA titers afterward the 5th days pi. Body temperature and the number of total leucocytes were slightly increased at the early stage of infection. but extremely decreased at the stage of collapse. HI titers of the sera started to increase at the 2nd to 3rd days pi reaching 512 to 1, 024 at the 4th to 5th day pi.

• Journal of Microbiology and Biotechnology
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• 제20권12호
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• pp.1605-1613
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• 2010

Twenty-nine P. polymyxa strains isolated from rhizospheres of various crops were clustered into five genotypic groups on the basis of BOX-PCR analysis. The characteristics of several plant growth-promoting factors among the isolates revealed the distinct attributes in each allocated group. Under gnotobiotic conditions, inoculation of pepper roots with P. polymyxa isolates significantly increased the biomass in 17 of total 29 treated plants with untreated plants. Experiments on induced systemic resistance (ISR) against bacterial spot pathogen Xanthomonas axonopodis pv. vesicatoria in pepper by P. polymyxa strains were conducted and only one isolate (KNUC265) was selected. Further studies into ISR mediation by the KNUC265 strain against the soft-rot pathogen Erwinia carotovora subsp. carotovora in tobacco demonstrated that the tobacco seedlings exposed to either bacterial volatiles or diffusible metabolites exhibited a reduction in disease severity. In conclusion, ISR and plant growth promotion triggered by P. polymyxa isolates were systemically investigated on pepper for the first time. The P. polymyxa KNUC265 strain, which elicited both ISR and plant growth promotion, could be potentially used in improving the yield of pepper and possibly of other crops.

• Food Science and Biotechnology
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• 제16권1호
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• pp.99-103
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• 2007

The purpose of this study was to develop a simple detection method, possibly at the species-level, that allows for large-scale screening of bifidobacteria. Human fecal samples were plated on MRS-raffinose agar containing cysteine and neomycin sulfate, serving as selective pressure for bifidobacteria, and 0.003%(w/v) bromocresol green. All of the test strains grew well on this medium at $37{\pm}1^{\circ}C$, forming white colonies surrounded by yellow halos, which presented a sharp contrast against the green background. In this disc assay, the required incubation time to develop a yellowish zone varied with the species of Bifidobacterium that was tested, allowing for differential counts and easy identification at the species-level: 10-14 hr for B. bifidum, 20-22 hr for B. catenulatum and B. infantis. and 24-25 hr for B. longum and B. breve. No apparent color was observed for B. angulatum and B. adolescentis 28 hr after inoculation. To evaluate the results of pH indicator-based identification, individual isolates were subjected to a colony-PCR experiment with genus-specific primers. The amplified products from the isolates were in good accordance with those from the reference strains at a level of 95% agreement. These results suggest that the present method could be conveniently applied to cell counts, as well as to the preliminary identification of bifidobacteria from a variety of sample types including human feces, dairy products, and commercial probiotic supplements.

• Journal of Microbiology and Biotechnology
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• 제16권10호
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• pp.1622-1628
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• 2006

Bacteria from the Methylobacterium genus, called pink-pigmented facultative methylotrophic bacteria (PPFMs), are common inhabitants of plants, potentially dominating the phyllosphere population, and are also encountered in the rhizosphere, seeds, and other parts of plants, being versatile in nature. The consistent success of the Methylobacterium plant association relies on methylotrophy, the ability to utilize the one-carbon compound methanol emitted by plants. However, the efficiency of Methylobacterium in plant growth promotion could be better exploited and thus has attracted increasing interest in recent years. Accordingly, the present study investigated the inoculation effects of Methylobacterium sp. strains CBMB20 and CBMB 110 on seed imbibition to tomato and red pepper on the growth and accumulation of phytohormone levels under gnotobiotic conditions. Seeds treated with the Methylobacterium strains showed a significant increase in root length when compared with either the uninoculated control or Methylobacterium extorquens $miaA^-$ knockout mutanttreated seeds. Extracts of the plant samples were used for indole-3-acetic acid (IAA), trans-zeatin riboside (t-ZR), and dihydrozeatin riboside (DHZR) assays by immunoanalysis. The treatment with Methylobacterium sp. CBMB20 or CBMB 110 produced significant increases in the accumulation of IAA and the cytokinins t-ZR and DHZR in the red pepper extracts, whereas no IAA was detected in the tomato extracts, although the cytokinin concentrations were significantly increased. Therefore, this study proved that the versatility of Methylobacterium as a plant-growth promoting bacteria could be better exploited.

• The Plant Pathology Journal
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• 제23권1호
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• pp.22-25
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• 2007

Biocontrol activity of five strains of selected rhizo-bacteria were tested in tomato against bacterial wilt caused by Ralstonia solanacearum. After root bacterization the plants were grown in a perlite-hydroponic system. Upon challenge inoculation with the pathogen, all of the rhizobacterial strains efficiently suppressed the bacterial wilt in tomato in various rates, at maximum by the strain, Bacillus vallismortis strain EXTN-1. While the percent of infected plants in the non-bacterized control plants were 95%, it was only 65% in plants pre-treated with EXTN-1. It was also demonstrated that the movement of R. solanacearum within the stem was significantly hampered when the plants were root bacterized. As EXTN-1 has no antagonistic properties against R. solanacearum, the bacterial wilt was probably suppressed by a mechanism other than antibiosis. Previously, the strain had been proven to produce an efficient elicitor for inducing systemic resistance in many crops. As the present study confirmed that EXTN-1 has the ability for reducing the pathogen spread in tomato, the strain could be effectively used as a potential biocontrol agent against bacterial wilt.

• 대한수의학회지
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• 제44권4호
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• pp.539-549
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• 2004

Mean death time of inoculated embryonated egg is one of the methods to determine the virulence of the Newcastle disease viruses (NDV). Evaluation of tissue tropism of NDV in the host has been proposed as an another way to determine the pathogenicity of NDV based on the principal site of viral replication. To evaluate the tissue tropism among NDV, an immunohistochemistry(IHC) technique using monoclonal antibody was applied in one-day-old SPF chickens inoculated with different ND vaccine strains such as Ulster 2C, VG/GA and B1 viruses by eye drop instillation. The tissues used for this comparison were trachea, intestine, Harderian gland and cecal tonsil, which were collected at 0.5, 1, 2, 3, 5, 8, 10, 14 days post inoculation. Among test groups, chickens inoculated with B1 viurs, which is known to replicate in the respiratory system, have IHC positive staining mainly in the trachea and those inoculated with Ulster 2C have IHC positive staining mainly in the intestine. However, chickens inoculated with VG/GA strain have IHC positive staining in both the trachea and intestine. Therefore, a differences in tissue tropism among ND vaccine strains has been proved by the IHC technique. Based on this results, the IHC staining technique could be used to classify the NDV or to study the pathogenesis of NDV in chickens.