• The Plant Pathology Journal
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• 제39권4호
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• pp.409-416
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• 2023

Bacterial leaf blight of carrots caused by Xanthomonas hortorum pv. carotae (Xhc) is an important worldwide seed-borne disease. In 2012 and 2013, symptoms similar to bacterial leaf blight were found in carrot farms in Jeju Island, Korea. The phenotypic characteristics of the Korean isolation strains were similar to the type strain of Xhc. Pathogenicity showed symptoms on the 14th day after inoculation on carrot plants. Identification by genetic method was multi-position sequencing of the isolated strain JJ2001 was performed using four genes (danK, gyrB, fyuA, and rpoD). The isolated strain was confirmed to be most similar to Xhc M081. Furthermore, in order to analyze the genetic characteristics of the isolated strain, whole genome analysis was performed through the next-generation sequencing method. The draft genome size of JJ2001 is 5,443,372 bp, which contains 63.57% of G + C and has 4,547 open reading frames. Specifically, the classification of pathovar can be confirmed to be similar to that of the host lineage. Plant pathogenic factors and determinants of the majority of the secretion system are conserved in strain JJ2001. This genetic information enables detailed comparative analysis in the pathovar stage of pathogenic bacteria. Furthermore, these findings provide basic data for the distribution and diagnosis of Xanthomonas hortorum pv. carotae, a major plant pathogen that infects carrots in Korea.

• 아시안잔디학회지
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• 제6권2호
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• pp.89-98
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• 1992

Rhizoctonia oryzae, R. oryzae-sativae 및 R. solani의 균사융합군의 각 균주에 대한 배양특성과 creeping bentgrass 및 들잔디에 대한 병원성과 살균제의 효과에 대하여 조사하였던 바 다음과 같다. 1. 균사생육에 미치는 온도의 영향을 보면 네가지 형으로 나눌 수 있는데, R. oryzae와 R. oryzae-sativae는 생육적온이 $30~35^{\circ}C$인 호고온형이었고, R. solani의 균사융합군의 각 균주도 세가지 형으로 나뉘었는데, 즉 생육적온이 $25~30^{\circ}C$인 고온형, 20~25$^{\circ}C$인 중간형 및 $20^{\circ}C$인 저온형이었다. 2. 접종실험에서 creeping bentgrass에 대해서는 R. oryzae와 R. solani의 AG-1( I A), AG-1( I B), bentgrass분리균 및 벼 분리균이 강한 병원성을 나타냈고, 그 다음으로 AG-2-1, AG-4, AG-5 및 AG-2-2가 중 또는 약한 병원성을 나타냈다. 들잔디에 대해서는 R. oryzae와 R. solani의 들잔디 분리균이 강한 병원성을 나타냈고 AG-1( I B)와 AG-5가 중정도의 병원성을 나타냈다. 3. 살균제의 효과는 creeping bentgrass의 brown patch병과 들잔디의 large patch병에 대해서 capro와 mytan등이 가장 좋았고 brown patch병에 대해서는 thiopan과 pencycuron이, large patch병에 대해서는 tolos와 thiopan이 각각 그 다음으로 좋았다.

• 한국가금학회지
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• 제31권2호
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• pp.119-128
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• 2004

Highly Pathogenic Avian Influenza (HPAI) is a very acute systemic disease in poultry, particularly in chickens and turkeys caused by HPAI viruses. An outbreak of HPAI caused by subtype H5N1, was first reported in a broiler breeder farm on December 10, 2003 in Korea, although there had been twenty one outbreaks of the disease reported in the world before. Since mid-December 2003, eight Asian countries have confirmed outbreaks of HPAI due to the same subtype. The outbreak has also resulted in at least twenty three fatal human cases in Vietnam and Thailand as of May 17, 2004 according to the WHO. Regarding the first outbreak of recent Asian HPAI, it has been suspected that some Asian countries with the exception of Korea and Japan veiled the fact of HPAI outbreaks since the last half of 2003, even though it was first reported in Korea. There have been total nineteen outbreaks of HPAI among chicken and duck farms in 10 provinces in Korea since Dec. 2003 and approximately 5,280,000 birds were slaughtered from 392 farms for eradication of the disease and preemptive culling. The origin of the H5Nl HPAI virus introduced into the country are unknown and still under epidemiological investigation. Current status of outbreaks and characteristics of HPAI will be reviewed and discussed on the basis of genetic, virological, clinicopathological, and ecological aspect, as well as future measures for surveillance and prevention of the disease in Korea.

• 한국식물병리학회지
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• 제11권1호
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• pp.30-38
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• 1995

Anthracnose fungi associated with soybean (Glycine max), small red bean (Vigna angularis), and green bean (Phaseolus radiatus var. aurea) were compared with respect to cultural characteristics, morphological aspects, and pathogenicity. From the legumes, four different species of Colletotrichum were identified based on their morphological characters : C. truncatum, C. destructivum, C. trifolii and C. gloeosporioides. Colonies of Colletotrichum spp.on culture media varied in colour and growth habits depending upon the media and isolates. In general, formation of conidia, setae, and perithecia on water agar leaf medium was better than that on potato dextrose agar medium under near ultraviolet light. In cross inoculation tests, isolates of C. truncatum, c. destructivum, C. trifolii and C. gloeosporioides could infect soybean, small red bean, and green bean at different growth stages. There were some differences in pathogenicity or susceptibility depending on crops tested. C. truncatum was the most virulent and major pathogenic species among the four species.

• 한국식물병리학회지
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• 제11권1호
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• pp.98-99
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• 1995

A disease causing fruit rot and leaf and vine blight on watermelon was found in Euseong in July, 1991 and in Bonghwa, Kyungpook province in August, 1993. Abundant zoosporangia characteristics of Phytophthora capsici were formed on the surface of the infected fruits. The zoosporangia were ovoid to ellipsoid, tapering to the base and with conspicuous papilla. The fungus isolated from the infected fruits was pathogenic on seedlings of watermelon, pumpkin, and pepper. The morphological characteristics and host range agreed with those of P. capsici. The watermelon disease caused by P. capsici was reported long time ago in Japan and America but rot yet in Korea. Thus, the disease on watermelon caused by P. capsici is reported as a new record in Korea.

• 식물병연구
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• 제7권3호
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• pp.145-149
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• 2001

2000년 5월 경북 경산시 진량읍 대구대학교에 소재하는 등나무에 암종이 심하게 형성되어 있음을 발견하였다. 병원체를 분리하고 얻어진 병원세균으로 병원성을 확인한 후 동정을 행하였다. 그 결과 병원세균은 일반 세균학적 성상 및 병원성에 의하여 Pantoea agglomerans pv. milletiae로 동정이 되었으며 이 병은 우리나라에서 처음 보고되는 것으로서, 이들 병원세균에 의한 그 병명을 "등나무혹병'이라 명명하기를 제안한다.제안한다.

• 한국식물병리학회지
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• 제14권5호
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• pp.467-472
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• 1998

Gray mold rot of perilla was epidemic at Kangdong, Pusan and Miryang, Kyungnam in 1997 and 1998. The incidence of this disease ranged form 21.3 to 68.1% at Kangdong area. Leaf necrosis initially appeared on the edge of the infected leaves, and it was developed to the center of the leaves forming typical V-shaped brown necrotic lesions. Under high moisture condition, abundant mycelia of the pathogen was formed on the surface of the lesions. Infected stems became slender and were completely blighted up to the top of the plant. Two isolates, LVF12 and SD7, were isolated from diseased lesions showing typical symptoms, and the pathogenicity was tested using mycelial disks and conidial suspension inoculation. The developed symptoms were same as the naturally produced ones. These two pathogenic fungi were identified as Botrytis cinerea based on the morphological characteristics using a microscope and a scanning electron microscope, and cultural characteristics. This is the first report of gray mold or perilla in Korea.

• 한국균학회지
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• 제51권4호
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• pp.471-490
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• 2023

Soil is a rich source of saprobic and pathogenic fungi in crop cultivation areas. Compared with that of the fruit trees, scarce information is available regarding the fungi present in orchard soils in Korea. We sampled rhizosphere soils of apple and pear trees from several orchards in Cheongju, Anseong, and Cheonan, Korea. During the processing of soil fungi, seven unrecorded species of the phylum Ascomycota were isolated. These included Acrocalymma walkeri, Clonostachys krabiensis, Coniella vitis, Cosmospora diminuta, Lasiobolidium spirale, Penicillium vallebormidaense, and Pseudothielavia arxii. All the species were identified and described based on morphological characteristics and molecular analysis of the ITS1-5.8S-ITS2 region and the large subunit of nuclear ribosomal RNA gene and partial β-tubulin gene (BenA) sequences. Descriptions and illustrations of the morphological characteristics are provided.

• Journal of Microbiology and Biotechnology
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• 제34권4호
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• pp.854-862
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• 2024

Lactobacillus is a commonly used probiotic, and many researchers have focused on its stress response to improve its functionality and survival. However, studies on persister cells, dormant cells that aid bacteria in surviving general stress, have focused on pathogenic bacteria that cause infection, not Lactobacillus. Thus, understanding Lactobacillus persister cells will provide essential clues for understanding how Lactobacillus survives and maintains its function under various environmental conditions. We treated Lactobacillus strains with various antibiotics to determine the conditions required for persister formation using kill curves and transmission electron microscopy. In addition, we observed the resuscitation patterns of persister cells using single-cell analysis. Our results show that Lactobacillus creates a small population of persister cells (0.0001-1% of the bacterial population) in response to beta-lactam antibiotics such as ampicillin and amoxicillin. Moreover, only around 0.5-1% of persister cells are heterogeneously resuscitated by adding fresh media; the characteristics are typical of persister cells. This study provides a method for forming and verifying the persistence of Lactobacillus and demonstrates that antibiotic-induced Lactobacillus persister cells show characteristics of dormancy, sensitivity of antibiotics, same as exponential cells, multi-drug tolerance, and resuscitation, which are characteristics of general persister cells. This study suggests that the mechanisms of formation and resuscitation may vary depending on the characteristics, such as the membrane structure of the bacterial species.

• 한국수산과학회지
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• 제35권6호
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• pp.545-550
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• 2002

금강 하구에서 분리한 용혈독소를 생산하는 V. mimicus와 유사하지만 분류되지 않은 기수성 Vibrio속으로 추정되는 균주 Vibrio sp. E10 (V. kunsan)의 세균학적 특징은 다음과 같다. 기본적인 생화학적 시험과 전자현미경 상의 형태에서는 V. mimicus와 유사하였지만 TCBS 배지 상의 colony 형태는 V. vulnifirus와 유사하였으므로 V. mimicus와는 차이를 보였다. Human과 sheep blood agar에서의 뚜렷한 용혈환과 rat에 피부혈관투과항진 작용으로 용혈독성이 있었으며, mouse에 대한 치사독성이 있었으므로 병원성이 확인되었다. 생육 가능한 환경 조건은 염도 0$\~$$4.5\%$, pH 6.2$\~$9.2, 온도 $14\~42^{\circ}C$이 었다. Vibrio sp. E10의 16S rDNA 염기서열은 10여종의 V. cholerae와 1종의 Vibrio mimicus의 염기서열과 $99\%$의 상동성을 보여 유사 종으로 판명되었다. 그러나 세균 자동동정기를 이용한 동정 결과, genus는 Vibrio 속으로 동정되었으나 species는 일치하는 균종이 없었다. 알려진 Vi-brio속 중에서 유사성이 높았던 V. mimicus와 비교해 볼 때 18종류의 항목이, V. cholerae와는 11종류의 항목이 다른 반응을 나타내어 미분류 균종으로 확인되었다.