• 식물병연구
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• 제19권2호
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• pp.95-101
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• 2013

Xanthomonas campestris pv. campestris(Xcc)에 의한 검은썩음병은 세계적으로 배추과 작물에 발생하여 큰 피해를 주고 있는 주요 식물병이다. Xcc에 대한 양배추의 효율적인 저항성 검정법을 확립하기 위해, Xcc에 대한 저항성 정도가 서로 다른 '루비아', '오조라', '그린핫', 'Saint', 'Joeun-ACE', 'Wonderball' 및 'XCCR 500' 등 7개 양배추 품종을 대상으로 접종 방법, 접종 위치, 재배 기간 그리고 재배 온도에 따른 검은썩음병 발생을 조사하였다. 양배추 품종들의 저항성은 18핀이나 가위를 사용하여 접종하는 것보다 핀셋(mouth-tooth forceps)을 사용하여 접종하였을 때 가장 큰 차이를 보이며, 직접적으로 엽맥에 접종하는 것보다 엽맥 주변에 접종이 더 효과적이었다. 그리고 접종한 유묘를 $30^{\circ}C$ 보다 $22^{\circ}C$에서 재배하였을 때에 감수성과 저항성 반응이 더 분명하게 나타났다. 이상의 결과로부터 양배추 검은썩음병에 대한 효과적인 저항성 검정법으로 4주 재배한 유묘의 엽맥 주변을 핀셋(mouth-tooth forceps)으로 상처 접종한 후 $22^{\circ}C$ 생육상에서 재배하는 방법을 제안하고자 한다.

• 한국자원식물학회지
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• 제27권6호
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• pp.687-700
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• 2014

Rice blast (Magnaporthe oryza B.) is one of the most important diseases in rice that causing great yield losses every year around the world. It is important to screen valuable genetic resources for improving blast resistance. This study was conducted to identify the blast resistance in 279 Korean rice landraces using blast nursery tests and isolate inoculum screening. The results showed that 11 landrace accessions found to be resistant to rice blast in blast nursery and inoculation screening tests and the degree of lesions in most accessions showed that they were susceptible to reactions. In order to find the distribution of blast resistant genes, a molecular survey was conducted to identify the presence of major blast resistance (R) gene in 279 Korean landraces. The results revealed that their frequency distribution was Pik-m (36.2%), Piz (25.4%), Pit (13.6%), and Pik (10%). Besides, the frequency distribution of Piz-t, Pii, Pik-m/Pik-p, Pi-39(t), Pib, Pi-d(t)2, Pita/Pita-2 and Pi-ta genes were identified as less than 10%. The results did not consist with the reactions against blast diseases between genotypes and phenotypic part of the nursery tests and isolate inoculation. For concluding these results, we used genome-wide SSR markers that have closely been located with resistance genes. The PCoA analysis showed that the landrace accessions formed largely two distinct groups according to their degree of blast resistance. By comparing genetic diversities using polymorphic information contents (PIC) value among the resistant, total and susceptible landraces, we found that PIC values decreased in four SSR markers and increased in six markers in the resistant accessions, which showed contrary to total and susceptible groups. These regions might be linked to resistance alleles. In this study, we evaluated the degree of blast resistance and the information about the distribution of rice blast resistant genes in Korean rice landraces. This study might be the basis for association analysis of blast resistance in rice.

• 생약학회지
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• 제34권2호통권133호
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• pp.142-144
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• 2003

Acetone extracts of 301 strains of marine-derived fungus were tested for antimicrobial activity against three strains of bacteria. The bacteria consisted of three pathogens, Staphylococcus aureus, methicillin-resistant S. Aureus, and multidrug-resistant S. aureus. The acetone extracts of 10 strains (MFA117, MFA130, MFA134, MFA206, MFA217, MFA268, MFA277, MFA291, MFA292, MFA301) showed strong activity, inhibiting 100% of the bacterial growth. These antimicrobial active strains were cultlued in SWS medium on a 1 L scale and the resulting broth and mycelium were extracted to afford mycelium extract (000M) and broth extract (000B), respectively. Antimicrobial activity for all extracts has been tested as the results, the mycelium extract of one strain (217M) and the broth extracts of 9 strains (117B,130B, 134B, 206B, 268B, 277B, 291B, 292B, 301B) exhibited relatively high levels of activity at minimal inhibitory concentration (MIC) values of $500-125\;{\mu}g/mL$ range. Among them, the extracts, 277B, 291B, 292B and 301B showed the most significant antimicrobial activity with $IC_{50}$ values of $125\;{\mu}g/mL$.

• 한국자기공명학회논문지
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• 제6권1호
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• pp.69-77
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• 2002

During the screening of material which has the antimicrobial activity against aminoglycoside-resistant bacteria, A new material $\varepsilon$-(L-$\beta$-Iysine) polypeptide from a culture medium of Streptomyces sp.(DWGS2) was isolated, and the structure and the physicochemical properties of the new material were elucidated. The new material was separated by column chromatography of the culture medium using Dowex1$\times$2, Silica gel, and Sephadex LH20 etc. The chemical structure and molecular weight were determined with the data of various NMR experiments, MALDI mass, and ESI mass experiments. The antimicrobial activity of $\varepsilon$-(L-$\beta$-Iysine) polypeptide is not only better than equal to the activity of known aminoglycoside type of antibiotics(MIC=3.125 - 6.25ug/mL) but also effective against aminoglycoside-resistant bacteria and fungi. If the mechanism of antimicrobial activity against aminoglycoside- resistant bacteria is figured out, the $\varepsilon$-(L-$\beta$-Iysine) polypeptide can be utilized for the treatment of diseases caused by aminoglycoside-resistant bacteria.

• 식물병연구
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• 제9권4호
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• pp.224-228
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• 2003

우리 나라 농가에서 담배역병 방제약제로 사용되고 있는 Metalaxyl의 약제 저항성균 발생억제 및 방제를 위한 대체 약제를 선발하기 위하여 시중에서 판매되고 있는 역병방제용 약제 중 Dimethomorph를 비롯한 5종의 약제를 구입하여 시험하였다. 실내 시험에서는 Propamocarb hydrochloride는 Metalaxyl과 유사한 반응을 보여 서로 교차저항성이 있는 것으로 조사되었으며 Oxadixyl + Mancozeb, Dimethomorph + Mancozeb 등이 실내시험 및 포장시험 결과 약효가 우수하여 Metalaxyl 대체약제로 선발되었다.

• 대한수의학회지
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• 제39권2호
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• pp.376-382
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• 1999

A methicillin-resistant Staphylococcus aureus (MRSA) isolate was recovered from a 9-month-old female Shih-Tzu dog with canine distemper virus infection. We performed in vitro antimicrobial susceptibility test to determine the most effective antimicrobial drug against the isolate and thus, to emphasize its potential clinical importance in animal practices. Isolate was confirmed MRSA by oxacillin agar screening test. The isolate was fully resistant to all $\beta$-lactam antibiotics and was susceptible to glycopeptides. Of the other antibiotics, mupirocin, TMP/SMZ (trimethoprim-sulfamethoxazole), and chloramphenicol showed inhibitory effect at the concentration of 4x MIC. The MICs ranged 0.25->$128{\mu}g/ml$, and MBCs ranged 0.5->$128{\mu}g/ml$. The combined TMP/SMZ with cefamandole or novobiocin showed synergistic effect, whereas the combination of novobiocin plus cefamandole or teicoplanin resulted in antagonistic effects. Although MRSA in animals so far has been reported in the geographically limited countries, at least theoretically, it could be occurred in the future more frequently through either human or animal origin. The use of this combination may be of value in this situation. As with all antimicrobial agents, inappropriate or unnecessarily prolonged therapy may contribute to the emergence of resistance strains and loss of efficacy.

• 한국미생물·생명공학회지
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• 제32권1호
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• pp.47-51
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• 2004

암세포가 특정 항암제에 의해 내성을 획득하면 구조가 상이한 타 항암제에도 교차내성을 나타내는 이른바 암세포의 다약제 내성이 암 화학요법에 있어서 가장 심각한 문제가 되고 있다. 본 연구에서는 다약제 내성 암세포주인 CL02 세포를 이용하여 cellulose 용해성 점액세균인 Sorangium cellulosum의 60여종의 균주를 대상으로 다약재 내성 암세포에 유효한 항암물질을 탐색하는 과정에서, 균주 JW1006의 대사산물에서 강한 증식억제 활성을 발견하고 그 활성 본체로서 macrolide계 화합물인 Disorazoles $A_1$과 $A_2$를 분리하였다 Disorazoles $A_1$과 $A_2$는 인체기원의 암세포에 대해 모두 강한 세포독성($IC_{50}$ ＜0.04 ng/$m\ell$)을 나타낼 뿐 아니라 다약제내성 세포주인 CL02와 cisplatin내성 세포주인 CP70에 대해서 감수성 세포주와 동일한 활성을 나타내어 다약제 내성을 극복하는 우수한 활성 물질임을 확인하였다

• 한국유기농업학회지
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• 제23권3호
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• pp.497-507
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• 2015

내병성 포도 신품종을 육성하기 위해서는 병해 저항성인 유전자원을 선발하는 것이 요구된다. 본 연구에서는 머스카딘포도와 플로리다 교잡종포도를 대상으로 병원균을 상처접종하여 포도나무 줄기혹병에 대한 저항성을 검정하였다. 3종류의 Agrobacterium vitis 균주를 접종한 포도나무는 품종 간에는 혹의 형성에 차이를 나타내었지만, 병원균의 균주 간에는 차이가 나타나지 않았다. 머스카딘포도는 많은 품종이 감수성이었으며, 'Gold Isle'과 'Africa Queen'은 고도의 감수성이었고 'Welder'와 'Jumbo'는 저항성이었다. 플로리다 교잡종포도는 머스카딘포도에 비해 덜 민감하였으며 'Daytona'와 'Stover' 등은 감수성이고, 'Blanc du Bois'는 중도감수성이었다. 본 연구는 머스카딘포도를 대상으로 줄기혹병에 대한 품종저항성을 판별함으로써 아속간 교잡을 통한 줄기혹병 저항성 포도 신품종육성에 중요한 정보를 제공할 것이다.

• 한국미생물·생명공학회지
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• 제19권4호
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• pp.343-347
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• 1991

Tobramycin 고생산성 변이주를 쉽고 신속하게 선별하 수 있는 screening 방법을 개발하였다. 고농도의 apramycin이 포함된 배지를 사용함으로서 nebramycin 생산성이 낮은 변이주들은 1차적으로 제거할 수 있었다. 모균주인 S. tenerbarius ATCC 17920에는 저지환을 나타내지 못하고 생산성이 향상된 변이주의 경우에만 저지환을 형성하는 strain No.23을 토양으로부터 분리하여 Ps. paucimobilis로 동정하였고 1차 선별된 변이주들 중 tobramycin 생산성이 높은 균주들을 선별하기 위한 피검균으로 사용하였다. 이러한 screening 전략으로 strain No.23에 명확히 저지환을 나타내는 변이주 58주를 얻었고, HPLC를 이용하여 각 변이주의 tobramycin 생산성을 비교 측정한 결과 모균주에 비해 3-8배 생산성이 향상되었음을 확인하였다.

• Biotechnology and Bioprocess Engineering:BBE
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• 제11권2호
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• pp.89-95
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• 2006

Potato plants carrying the Ry gene are extremely resistance to a number of potyviruses, but it is not known which variety expressed the resistance. In this investigation, combined classical and molecular techniques were used to identify virus resistance potatoes. Mechanical inoculation of 32 varieties of Korean potato cultivars, with potato virus Y (PVY), induced various symptoms, such as mosaic, yellowing, necrosis, mottle, vein clearing and vein bending. Different virus spreading patterns were observed, such as highly sensitive, moderate and resistant to $PVY^o$ inoculated leaves in different cultivars. From the results of double antibody sandwich-enzyme links immunosorbant assays (DAS-ELISA), coupled with reverse transcription polymerase chain reaction (RT-PCR), Winter valley and Golden valley were found to be highly susceptible and resistant cultivars to $PVY^o$ respectively. TEM was used as a complementary method to conform the localization of the virus in leaf tissues. TEM detect virus particles in Golden valley, where, ELISA and RT-PCR were unable to detect the CP gene. However, the interior part of the tissues was severely deformed in $PVY^o$ infected Winter valley, than Golden valley The Ry gene is involved in an induced response in $PVY^o$ infected Golden valley plants. The methods described in this study could be applied for the screening and development of antiviral potatoes.