• Asian-Australasian Journal of Animal Sciences
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• 제29권10호
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• pp.1490-1499
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• 2016

In this study, 69 lactobacilli isolated from Tibetan Qula, a raw yak milk cheese, were screened for their potential use as probiotics. The isolates were tested in terms of: Their ability to survive at pH 2.0, pH 3.0, and in the presence of 0.3% bile salts; tolerance of simulated gastric and intestinal juices; antimicrobial activity; sensitivity against 11 specific antibiotics; and their cell surface hydrophobicity. The results show that out of the 69 strains, 29 strains (42%) had survival rates above 90% after 2 h of incubation at pH values of 2.0 or 3.0. Of these 29 strains, 21 strains showed a tolerance for 0.3% bile salt. Incubation of these 21 isolates in simulated gastrointestinal fluid for 3 h revealed survival rates above 90%; the survival rate for 20 of these isolates remained above 90% after 4 h of incubation in simulated intestinal fluid. The viable counts of bacteria after incubation in simulated gastric fluid for 3 h and simulated intestinal fluid for 4 h were both significantly different compared with the counts at 0 h (p<0.001). Further screening performed on the above 20 isolates indicated that all 20 lactobacilli strains exhibited inhibitory activity against Micrococcus luteus ATCC 4698, Bacillus subtilis ATCC 6633, Listeria monocytogenes ATCC 19115, and Salmonella enterica ATCC 43971. Moreover, all of the strains were resistant to vancomycin and streptomycin. Of the 20 strains, three were resistant to all 11 elected antibiotics (ciprofloxacin, erythromycin, tetracycline, penicillin G, ampicillin, streptomycin, polymyxin B, vancomycin, chloramphenicol, rifampicin, and gentamicin) in this study, and five were sensitive to more than half of the antibiotics. Additionally, the cell surface hydrophobicity of seven of the 20 lactobacilli strains was above 70%, including strains Lactobacillus casei 1,133 (92%), Lactobacillus plantarum 1086-1 (82%), Lactobacillus casei 1089 (81%), Lactobacillus casei 1138 (79%), Lactobacillus buchneri 1059 (78%), Lactobacillus plantarum 1141 (75%), and Lactobacillus plantarum 1197 (71%). Together, these results suggest that these seven strains are good probiotic candidates, and that tolerance against bile acid, simulated gastric and intestinal juices, antimicrobial activity, antibiotic resistance, and cell surface hydrophobicity could be adopted for preliminary screening of potentially probiotic lactobacilli.

• 식물병연구
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• 제16권3호
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• pp.279-284
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• 2010

Plasmodiophora brassicae에 의한 배추 뿌리혹병은 전 세계적으로 발생하여 큰 피해를 주고 있다. 본 연구에서는 관주 접종을 이용한 효율적인 배추 뿌리혹병 저항성 검정법을 확립하기 위하여, 레이스 9인 GN-1 균주를 사용하여 토양 종류, 접종원 농도, 배추 생육시기, 접종 후 배양 기간 등의 발병 조건에 따른 뿌리혹병 발생을 조사하였다. 혼합토양(원예용 상토:밭 토양=1:1, v/v)과 달리, 원예용 상토에서는 P. brassicae 접종농도가 증가함에 따라 배추 뿌리혹병 발생도 증가하였다. 접종원 농도는 폿트 당 $4.0{\times}10^8$개의 포자로 접종하였을 때 그리고 접종을 위한 배추는 파종 후 10일 유묘가 적합하였다. 안정적인 발병을 위해서, 접종한 배추 유묘는 3일 동안 $20^{\circ}C$ 생육상에서 하루에 12시간 광을 처리하며 배양한 후 온실($25{\pm}5^{\circ}C$)에서 5주 동안 재배한 후에 병조사하는 것이 요구되었다. 확립한 배추 뿌리혹병 저항성 검정법을 이용하여, 시판 중인 뿌리혹병 저항성 품종 25종과 감수성 품종3종의 P. brassicae GN-1 균주에 대한 저항성 정도를 실험한 결과, 모든 저항성 품종들은 뿌리혹병에 대하여 뚜렷한 저항성을 나타내었고, 감수성 품종들은 발병도 3.5 이상의 높은 감수성을 보였다. 따라서 이 방법은 배추의 뿌리혹병 저항성을 검정하기 위한 효율적인 검정법임을 알 수 있었다.

• 식물병연구
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• 제18권2호
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• pp.86-92
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• 2012

Plasmodiophora brassicae Woron.에 의한 뿌리혹병은 배추과 작물에 발생하는 전 세계적으로 가장 중요한 식물병 중 하나이다. 본 연구는 Brassica oleracea에 속하는 양배추와 브로콜리의 뿌리혹병에 대한 효율적인 저항성 검정 방법을 확립하기 위하여, 레이스 9인 GN1 균주를 이용하여 접종원의 농도와 P. brassicae 접종 후 배양 기간 등의 발병 조건에 따른 양배추와 브로콜리 뿌리혹병 발생을 조사하였다. 접종원의 농도는 14일 재배한 유묘에 포트 당 $2.5{\times}10^9$개의 포자를 접종하는 것이 적당하였으며, 안정적인 발병을 위하여 접종한 유묘는 3일 동안 $20^{\circ}C$ 생육상에서 하루에 12시간 광을 처리하며 배양하고, 그 후 온실($20{\pm}5^{\circ}C$)에서 5주 동안 재배한 후에 발병 정도를 조사하는 것이 요구되었다. 위의 검정법을 이용하여 레이스가 다른 P. brassicae 4개 포장 균주에 대한, 시판 중인 양배추 16종과 브로콜리 17종 품종의 저항성 정도를 실험한 결과, 레이스 9인 GN1, GN2 그리고 GS 균주에 대해서는 중도저항성을 보이는 몇 가지 품종이 있었다. 그러나 레이스 2인 YC 균주에 대해서는 실험한 모든 품종이 고도의 감수성 반응을 나타내었다. 따라서 이 방법은 양배추와 브로콜리 뿌리혹병 저항성을 검정하기 위한 효율적인 검정법이라는 것을 알 수 있었다.

• 한국응용곤충학회지
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• 제20권4호
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• pp.207-211
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• 1981

수도 주요해충 벼멸구의 내충성품종선별방법을 개발하기 위하여 방사성동위원소 P-32를 이용한 섭식량과 식이선호성과의 관계를 조사중 다음과 같은 결과를 얻었다. 1. 식이선호에 의한 벼멸구의 선호도와 P-32 섭식량간에는 밀접한 관계가 있었다. 2. $ 2\~3$엽기 수도유묘를 표식할 때는 P-32의 비방사능이 $0.1{\mu}Ci/cc$가 되게 하고 처리방법은 근부를 24시간 이상 침적시킨 후 공시충은 48시간 흡즙시키는 것이 품종간차이를 비교하기 용역하였다. 3. 내충성 검정시 공시충은 성충을 이용하고 웅충보다 자충을 이용하는 것이 흡즙량의 차이가 커서 비교하기가 편리하였다.

• Journal of Applied Biological Chemistry
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• 제44권2호
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• pp.59-64
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• 2001

Pepper plants (Nogkwang, 60-day old) were inoculated with Phytophthora capsici to induce sesquiterpene cyclase associated with the biosynthesis of phytoalexin (capsidiol), a substance related to the defense against pathogens in plants. One day after inoculation, mRNA was isolated from the root, cDNA synthesized, and a library constructed in a ZAP express XR vector. The efficiency was $2{\times}10^6pfu/{\mu}g$. Sesquiterpene cyclase cDNA from Hyoscyamus muticus was labeled with $^{32}P$ and used as a probe for screening the cDNA library. After the third screening, 25 positive clones were selected. Through restrictive digestion and DNA gel-blot analysis, six different cyclase gene expressions were identified. PSC1B sequences of the six clones were determined, which were 1966 base pairs encoded 556 amino acids with an expected molecular weight of 63.8 kDa. Response against the pathogen was different between the resistant and susceptible peppers. After the infection of the pathogen, the expression of PSC genes continued in the resistant peppers while the plants were alive. The expression in the susceptible peppers lasted for only 4 days.

• Food Science and Biotechnology
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• 제18권5호
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• pp.1273-1278
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• 2009

This study aimed to evaluate the potential allergenicity of Cry proteins in insect-resistant genetically modified (GM) maizes (Bt11, MON810, and MON863) using serum screening tests. Serum samples were obtained from Korean children (0-15 years old) with allergic symptoms who had positive maize-specific IgE. The levels of serum specific IgE was measured by the Phadia ImmunoCAP system and considered as positive when they are 0.35 kU/L or higher. Cry proteins (Cry1Ab in Bt11, mCry1Ab in MON810, and Cry3Bb1 in MON863) were expressed in Escherichia coli and purified for serum screening. The reactivity of purified Cry proteins was confirmed by IgE immunoblots in 50 patients (maize-sensitized patients). There was no reaction between Cry proteins and sera from maize-sensitized patients. Our results suggest that these Cry proteins are not likely to cause allergic reactions. Further studies using more sera from patients with true clinical allergies are needed to evaluate the potential allergenicity of novel proteins in GM maize.

• 식물병연구
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• 제9권1호
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• pp.39-41
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• 2003

Erwinia carotovora subsp. carotovora에 의한 배추 무름병은 배추에서 가장 큰 문제가 되고 있는 병중 하나이다. 본 연구는 배추 품종별 무름병 저항성을 조기에 검정하고자 실시하였다. 선발된 균주를 이용하여 세균현탁액과 mineral oil을 4:1로 혼합하여 배추의 중앙 기부에 10m1 관주 접종하는 mineral oil 접종법으로 접종하였다. 국내의 3개 종묘회사와 대학으로부터 분양 받은 43개의 배추품종 및 계통의 저항성 정도를 조사하였다. 그 결과 C3-26, C3-28, C3-29, C29-51-51-52는 저항성, 강타배추, 금촌얼갈이, 미니배추, 금빛, DB50, 지부, 평층, 산촌배추는 감수성인 것으로 나타났으며, 나머지는 중간정도의 저항성을 나타냈다.

• Journal of Microbiology and Biotechnology
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• 제29권9호
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• pp.1478-1487
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• 2019

Ulcerative colitis (UC), a chronic inflammatory bowel disease, substantially impacts patients' health-related quality of life. In this study, an effective strategy for discovering high-efficiency probiotics has been developed. First, in order to survive in the conditions of the stomach and intestine, high bile salt-resistant and strong acid-resistant strains were screened out from the fecal flora of healthy adults. Next, the probiotic candidates were rescreened by examining the induction ability of IL-10 (anti-inflammatory factor) production in dextran sodium sulfate (DSS)-induced colitis mice, and Lactobacillus sakei 07 (L07) was identified and selected as probiotic P. In the end, fourteen bifidobacterium strains isolated from stools of healthy males were examined for their antimicrobial activity. Bifidobacterium bifidum B10 (73.75% inhibition rate) was selected as probiotic B. Moreover, the colonic IL-6 and $TNF-{\alpha}$ expression of the DSS-induced colitis mice treated with L. sakei 07 (L07) - B. bifidum B10 combination (PB) significantly decreased and the IL-10 expression was up-regulated by PB compared to the DSS group. Furthermore, Bacteroidetes and Actinobacteria decreased and Firmicutes increased in the DSS group mice, significantly. More interestingly, the intestinal flora biodiversity of DSS colitis mice was increased by PB. Of those, the level of B. bifidum increased significantly. The Bacteriodetes/Firmicutes (B/F) ratio increased, and the concentration of homocysteine and LPS in plasma was down-regulated by PB in the DSS-induced colitis mice. Upon administration of PB, the intestinal permeability of the the DSS-induced colitis mice was decreased by approximately 2.01-fold. This method is expected to be used in high-throughput screening of the probiotics against colitis. In addition, the L. sakei 07 - B. bifidum B10 combination holds potential in UC remission by immunomodulatory and gut microbiota modulation.

• 대한임상검사과학회지
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• 제42권2호
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• pp.86-91
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• 2010

We evaluated the performance of a novel screening test, PBP2a MRSA rapid kit (Dinona Inc., Iksan, Korea), for methicillin-resistant Staphylococcus aureus (MRSA) based on a immunochromatographic assay. The test is able to detect penicillin-binding protein 2a (PBP2a) using the nasal specimens from health care workers. The nasal specimens were obtained from 69 healthcare workers and were incubated in enrichment broth followed eight hours incubatin in BHI with cefoxitin $4{\mu}g/mL$. These broth were tested by PBP2a Rapid Kit. The enrichment broths were also directly tested for tube coagulase using the conventional identification method. 19 of 22 MRSA showed positive results by PBP2a rapid test and direct coagulase test (the sensitivity for detection of MRSA, 86.36%). While, 8 of 47 non-MRSA showed false positive results for the two tests. All of the 8 non-MRSA which showed false positive were co-colonizing isolates with MRCNS and MSSA. In addition, 46 of 49 methicillin-resistant staphylococci (MRS) showed positive results for PBP2a MRSA rapid kit (the sensitivity for detection of MRS, 93.8%), and all of 20 non-MRS showed negative results (specificity, 100%). The combination of PBP2a MRSA rapid kit and direct coagulase test showed the good sensitivity for detection of MRSA from anterior nares but frequently showed false positive results from the co-colonizing carrier with MRCNS and MSSA.

• The Plant Pathology Journal
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• 제17권3호
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• pp.149-153
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• 2001

A total of 2109 isolates of Botrytis cinerea were collected from infected plants fo strawberry, tomato, and cucumber in Korea from 1994 to 1996. Based on in virtotests for mycelial growth on potato-dextrose agar containing fungicides, the esolates were classified into six phenotypic groups : SSR, SRR, RSS, RRS, RSR, and RRR, representing sensitivity (S) or resistance (R) to carbendazim, procymidone, and diethofencarb. In that order the isolation frequencies of the SSR, SRR, RSS, RRS, RSR, and RRR phenotypes were 28.7, 1.1, 28.8, 39.4, 1.0, and 0.9%, respectively. Three isolates from each SSR, SRR, RSS, RRS, and RSR and an isolate of RRR phenotype were selected and evaluated for their fitness-related characteristics such as pathogenic aggressiveness, mycelial growth rate, sporulation, and sclerotial formation. Competitive abilities of the SSR, SRR, RSS, RRS, and RSR phenotypes were also compared by inculating mixtures of conidial suspensions of two phenotypes to cucumber plant, and then determining re-isolation frequencies from lesions. In general, significant differences in fitness-related characteristics, except pathogenic aggressiveness, were found not only between but also within phenotype groups. In the competitiveness tests, carbendazim-sinsitive phenotypes (SSR and SRR) were found to be more competitive than the resistant ones (RSS and RSR), whereas, the procymidone-resistant phenotypes (SRR and RRS) appeared to be more competitive than the sensitive ones (SSR, RSS, and RSR). There was no consistent dominance in competitiveness between the diethofencarb-resistant and sensitive phenotypes. The RSR phenotype was the least competitive among the five phenotypes.