• 식물병연구
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• 제21권2호
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• pp.99-102
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• 2015

오이모자이크바이러스(CMV)는 고추에 심한 피해를 주는 바이러스이다. 2013년 고추 품종 청양의 선단부위에 괴저증상이 나타난 식물체로부터 CMV를 순수 분리하였고 이 분리주를 CMV-GTN으로 명명하였다. CMV-GTN과 기존에 특성이 잘 알려진 CMV-Ca-P1을 대상으로 외피단백질의 아미노산 서열과 여러 기주식물에서 생물적 반응을 비교하였다. CMV-Ca-P1의 외피단백질 아미노산은 217개로 구성되어 있었으나, CMV-GTN은 아미노산 서열 57번째에 발린이 추가된 218개로 구성되어 있었다. CMV-GTN과 GeneBank에 등록된 다양한 CMV 분리주들의 외피단백질유전자 유사성은 96-99%였다. 생물 검정에서 토마토와 고추에서 병원성이 강하게 발현되는 CMV-GTN을 고추 품종에 대한 저항성 스크린을 위하여 선발하였다. 고추 시판 품종 135종에 대하여 CMV-GTN으로 검정하였고 CMV-Ca-P1과 저항성 반응을 비교하였다. 그 결과 CMV-GTN에 대하여 저항성 반응을 표현한 품종은 프레미엄, 중도 저항성 품종은 핫스타, 카이저, 굿쵸이스였다. 한편 CMV-Ca-P1에 대한 저항성 품종은 베로따와 카이저였다.

• 한국응용곤충학회지
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• 제22권3호
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• pp.208-212
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• 1983

콩씨스트선충의 방제를 위한 기초조사로서 우리나라에 분포하고 있는 공씨스트선충(Heteropera glycines)의 race를 검정하고 콩 장려 16품종들의 콩씨스트선충 race 5에 대한 저항성을 검정한 결과 다음과 같은 결론을 얻었다. 우리나라 콩 장려품종들 중에서 콩씨스트선충(Heterodera glycines) race 5에 대하여 저항성 을 나타내는 품종은 없었으나, 황금콩, 힐콩, 단엽콩 등이 비교적 선충의 증식이 적게되는 품종으로 나타났다. 본 실험에서 일본에서 공씨스트선출에 저항성 품종으로 육성된 "동북태"(Kaiden)는 아주 감수성으로 나타났으며, 기국에서 감수성 판별품종으로 사용되고 있는 "단엽콩" (Essex)과 "힐공"(Hill)은 다른 품종보다 선충의 증식이 적게 되었다. 우리나라의 콩씨스트선충은 지역에 따라서 race가 다르게 나타났나. 전남 화순에서는 race 1, 경남 염산과 경기도 수원에서는 race 5 그리고 경북 선산에서는 새로운 "race c" 등 3개의 race가 검정되었다. 이 실험에서 우리나라에도 공씨스트선충의 race 1, race 5 및 race c가 있다는 것이 처음으로 밟혀졌다.

• The Plant Pathology Journal
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• 제30권4호
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• pp.331-342
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• 2014

Given the lack of a resistant genetic pool in host plants, the introduction of exotic invasive pathogens can result in epidemics that affect a specific ecosystem and economy. Plant quarantine, which is designed to protect endemic plant resources, is a highly invaluable safeguard that should keep biosecurity with increasing international trade and global transportation. A total of 34 species of plant pathogens including Phytophthora infestans were documented as introduced from other countries into Korea from 1900 to 2010. The genus Phytophthora, classified in oomycetes, includes more than 120 species that are mostly recognized worldwide as highly invasive plant pathogens. After 2000, over 50 new species of Phytophthora were identified internationally as plant pathogens occurring in crops and forest trees. In Korea, Phytophthora is also one of the most serious plant pathogens. To date, 22 species (about one-fifth of known species) of the genus have been identified and reported as plant pathogens in the country. The likelihood of new exotic Phytophthora species being introduced into Korea continues to increase, thus necessitating intensive plant quarantine inspections. As new potential threats to plant health in Korea, six Phytophthora species, namely, P. alni, P. inundata, P. kernoviae, P. pinifolia, P. quercina, and P. ramorum, are discussed in this review with focus on history, disease, biology, management, and plant quarantine issues.

• 한국식품위생안전성학회지
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• 제7권2호
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• pp.107.2-119
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• 1992

Fish pathology is one of the main scientific bases upon which this expansion in aquaculture has been dependent and requires a wide knowledge of the environmental constraints, the physiology and characteristic of the various pathogens, the responses of the host, and the methods by which they may be controlled. The primary disease and parasite problems in aquaculture animals related to viral, bacteria, fungal and protozoan epizootics. Parasitic nematodes, trematodes and cestodes are commonly found in aquaculture animals, but seldom are they present in concentrations sufficient to cause significant problems, When an epizootic does occur and chemical treatment is indicated, the appropriate chemical must be selected an properly applied. We have antibiotics, sulfa, nitrofuran and other chemicals for treatment of fish diseases, Some may be mixed with the feed during formulation, added to the pellets of feed as a surface coating, given in the form of an injection or used as a bath. Even though a drug or chemical has been officially approved for use in aquaculture, the substance should never be used unless there is a clear need, Some of the reasions for this view are as follows: (1) the constant use of antibiotics can leak to the development of resistant strains of bacteria, (2) biofilter efficiency may be impaired or destroyed by chemicals added to closed recirculating water systems, and(3) the injudicious use of chemical can have a damaging effect on the environment as well as on human.

• Journal of Microbiology and Biotechnology
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• 제13권1호
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• pp.90-98
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• 2003

In vivo $^31p$ Nuclear Magnetic Resonance ($^31p$NMR) and metabolic studies were carried out on an acetic acid tolerant mutant, Zymomonas mobilis $ZM4/Ac^R$, and compared to those of the parent strain, Z. mobilis ZM4, to evaluate possible mechanisms of acetic acid resistance. This investigation was initiated to determine whether or not the mutant strain might be used as a suitable recombinant host far ethanol production from lignocellulose hydrolysates containing various inhibitory compounds. $ZM4/Ac^R$ showed multiple resistance to other lignocellulosic toxic compounds such as syringaldehyde, furfural, hydroxymethyl furfural, vanillin, and vanillic acid. The mutant strain was resistant to higher concentrations of ethanol or lower pH in the presence of sodium acetate, compared to ZM4 which showed more additive inhibition. in vivo $^31p$ NMR studies revealed that intracellular acidification and de-energization were two mechanisms by which acetic acid exerted its inhibitory effect. For $ZM4/Ac^R$, the internal pH and the energy status were less affected by sodium acetate compared to the parent strain. This resistance to pH change and de-energization caused by acetic acid is a possible explanation for the development of resistance by this strain.

• Journal of Microbiology and Biotechnology
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• 제23권8호
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• pp.1147-1153
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• 2013

Pectobacterium carotovorum subsp. carotovorum (formerly Erwinia carotovora subsp. carotovora) is a plant pathogen that causes soft rot and stem rot diseases in several crops, including Chinese cabbage, potato, and tomato. To control this bacterium, we isolated a bacteriophage, PP1, with lytic activity against P. carotovorum subsp. carotovorum. Transmission electron microscopy revealed that the PP1 phage belongs to the Podoviridae family of the order Caudovirales, which exhibit icosahedral heads and short non-contractile tails. PP1 phage showed high specificity for P. carotovorum subsp. carotovorum, and several bacteria belonging to different species and phyla were resistant to PP1. This phage showed rapid and strong lytic activity against its host bacteria in liquid medium and was stable over a broad range of pH values. Disease caused by P. carotovorum subsp. carotovorum was significantly reduced by PP1 treatment. Overall, PP1 bacteriophage effectively controls P. carotovorum subsp. carotovorum.

• Journal of Microbiology and Biotechnology
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• 제28권11호
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• pp.1771-1781
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• 2018

The emergence of multidrug-resistant microorganisms, as well as fungal infectious diseases that further threaten health, especially in immunodeficient populations, is a major global problem. The development of new antifungal agents in clinical trials is inferior to the incidence of drug resistance, and the available antifungal agents are restricted. Their mechanisms aim at certain characteristics of the fungus in order to avoid biological similarities with the host. Synthesis of the cell wall and ergosterol are mainly targeted in clinical use. The need for new approaches to antifungal therapeutic agents or development alternatives has increased. This review explores new perspectives on mechanisms to effectively combat fungal infections and effective antifungal activity. The clinical drug have a common feature that ultimately causes caspase-dependent cell death. The drugs-induced cell death pathway is associated with mitochondrial dysfunction, including mitochondrial membrane depolarization and cytochrome c release. This mechanism of action also reveals antimicrobial peptides, the primary effector molecules of innate systems, to highlight new alternatives. Furthermore, drug combination therapy is suggested as another strategy to combat fungal infection. The proposal for a new approach to antifungal agents is not only important from a basic scientific point of view, but will also assist in the selection of molecules for combination therapy.

• 한국미생물·생명공학회지
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• 제23권2호
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• pp.164-169
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• 1995

An endogenous cryptic plasmid, pBL1, which has been used to construct plasmid vectors for coryneform bacteria producing amino acids, was eliminated from Brevibacterium lactofermentum. The pBL1 was partially digested with Sau3AI and the resulting DNA fragments were subcloned into a suicide vector pEM1 which contains a kanamycin-resistant (km$^{r}$) gene. KM$^{r}$ B. lactofermentum transconjugants were obtained by conjugal transfer of the pEM1 derivatives containing pBL1 DNA fragments from Escherichia coli into B. lactofermentum. A km$^{r}$ transconjugant was analyzed to contain a plasmid pEB14, which occurred in vivo by homologous recombination between pBL1 and the conjugal-transferred plasmid. The pEB14 including the pEM1-derived km$^{r}$ gene was found to be lost concomitantly with km$^{r}$ phenotype, resulting in the construction of a pBL1-free strain of B lactofermentum. Based on transformation efficiencies and plasmid stability, the resultant pBL1- free strain is more useful than wild strain as a host cell for genetic manipulation. It could be concluded that foreign plasmid DNAs are efficiently isolated and analyzed from the pBL1-free strain because of the absence of endogenous pBL1 plasmid.

• 한국환경과학회지
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• 제5권5호
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• pp.605-610
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• 1996

시판중인 생굴을 대상으로 Vibrio 속을 숙주로 하는 bacteriophage의 분리를 시도하였다. 4 종의 Vibrio 속과 5 혈청형의 Vibrio parahaemolytius를 실험대상으로 한 결과 배brio parahaemolyticus 2 혈청형에서만 bacteriophage가 분리되었다. 분리된 phage의 plaque 크기는 0.4mm였으며 전자현미경적 형태는 미부가 뚜렷하지 않은 육각형의 두부가 관찰되었고 크기는 67nm$\times$83nm 였으며, PFV/ml은 1.25$\times$$10^{11}$이었다. 분리된 phage는 chloro-form에 감수성을 나타내었다. 분리된 phage의 genomic 특성을 규명하기 위하여 핵산을 분리한 결과 DNA로 판명되어졌으며 두 혈청형 모두 제한효소 처리한 결과 Eco R I으로 4부위의 절단양상과 Hind III로부터 14부위 절단양상이 관찰되었다.

• BMB Reports
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• 제38권5호
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• pp.507-516
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• 2005

Antimicrobial peptides (AMPs) have been isolated and characterized from tissues and organisms representing virtually every kingdom and phylum. Their amino acid composition, amphipathicity, cationic charge, and size allow them to attach to and insert into membrane bilayers to form pores by 'barrel-stave', 'carpet' or 'toroidal-pore' mechanisms. Although these models are helpful for defining mechanisms of AMP activity, their relevance to resolving how peptides damage and kill microorganisms still needs to be clarified. Moreover, many AMPs employ sophisticated and dynamic mechanisms of action to carry out their likely roles in antimicrobial host defense. Recently, it has been speculated that transmembrane pore formation is not the only mechanism of microbial killing by AMPs. In fact, several observations suggest that translocated AMPs can alter cytoplasmic membrane septum formation, reduce cell-wall, nucleic acid, and protein synthesis, and inhibit enzymatic activity. In this review, we present the structures of several AMPs as well as models of how AMPs induce pore formation. AMPs have received special attention as a possible alternative way to combat antibiotic-resistant bacterial strains. It may be possible to design synthetic AMPs with enhanced activity for microbial cells, especially those with antibiotic resistance, as well as synergistic effects with conventional antibiotic agents that lack cytotoxic or hemolytic activity.