• 한국균학회지
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• 제34권2호
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• pp.122-124
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• 2006

2005년 3월경 경남농업기술원 움막저장고에서 저장중이던 초석잠의 덩이줄기에 이상증상이 발생하였다. 병징은 초석잠 덩이줄기 부분이 수침상으로 물러지고 썩으면서 병반부위에 회색의 곰팡이가 많이 생겼다. 분생포자는 무색, 단포자이며 난형 또는 타원형으로 크기는 $5{\sim}16{\times}4{\sim}12{\mu}m$였다. 분생포자경은 갈색으로 격막이 있고 나무가지 모양이며, 폭은 $14{\sim}30{\mu}m$였다. 균사생육과 균핵형성 적온은 $20^{\circ}C$였다. 초석잠에서 병징과 병원균의 균학적 특징, 병원성을 조사한 결과 Botrytis cinerea Persoon:Fries에 의한 초석잠 잿빛곰팡이병으로 동정하였다.

• Mycobiology
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• 제35권2호
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• pp.91-96
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• 2007

In the present study we first report in Korea the identification and characterization of Fusarium oxysporum isolated from rotten stems and roots of paprika (Capsicum annuum var. grossum) at Masan, Kyungsangnamdo in 2006. The fungal species produced white aerial mycelia accompanying with dark violet pigment on PDA. The optimal temperature and pH for the growth of the species was $25^{\circ}C$ and pH 7, respectively. Microscopic observation of one of isolates of the species shows that its conidiophores are unbranched and monophialides, its microconidia have oval-ellipsoidal shape with no septate and are of $3.0{\sim}11{\times}1.5{\sim}3.5\;{\mu}m$ sizes, its macroconidia are of $15{\sim}20{\times}2.0{\sim}3.5\;{\mu}m$ sizes and have slightly curved or slender shape with $2{\sim}3$ septate. The results of molecular analysis show that the ITS rDNA of F. oxysporum from paprika shares 100% sequence identity with that of known F. oxysporum isolates. The identified species proved it's pathogenicity by causing rotting symptom when it was inoculated on paprika fruits. The growth of F. oxysporum from paprika was suppressed on PDA by agrochemicals such as benomyl, tebuconazole and azoxystrobin. The identified species has the ability of producing extracelluar enzymes that degrade cellobiose and pectin.

• 한국균학회지
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• 제37권2호
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• pp.155-160
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• 2009

The production of dihydroxynaphthalene (DHN) melanin is known to be essential factor for pathogenicity in Colletotrichum lagenarium. However, the genetic diversity of melanin genes was not much known among Colletotrichum spp. To investigate the variability of melanin gene in Colletotrichum spp. that cause anthracnose on diverse crops including tomato, we cloned and sequenced partial sd, one of DHN melanin genes encoding for scytalone dehydratase, from eight strains of C. coccodes, C. acutatum, C. truncatum C. caricae, and C. musae. The size of PCR-amplified sd ranged 437 bp to 545 bp. The nucleotide sequence identity of sd among the Colletotrichum strains tested varied from 49% to 99%. All of the PCR-amplified sd from eight strains contain an intron and have two exons coding for 122 amino acids. Overall, the size and nucleotide sequence of sd varied among the five Colletotrichum spp. Sequence identity of the predicted scytalone dehydratase protein of 122 amino acids ranged 50 to 99%. Phylogentic analysis based on the sd nucleotide sequences revealed that the five Colletotrichum spp. could be genetically divided.

• 한국균학회지
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• 제41권3호
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• pp.197-199
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• 2013

2011년 7월 경상남도농업기술원 시험포장에서 S. rolfsii에 의한 옥수수 흰비단병 증상이 발생되었다. 병징은 줄기가 수침상으로 물러지고 갈색으로 변하면서 시들어 말라 죽는다. 병반부와 토양 표면에 흰색의 곰팡이가 발생하며 갈색의 작은 둥근 균핵이 형성되었다. 감자한천배지에서 균총은 흰색이고 잘 자라며 갈색의 작은 둥근 균핵을 많이 형성하였다. 균핵의 크기는 1~3 mm이며 균사의 폭은 $4{\sim}8{\mu}m$였다. 균사생육과 균핵형성 적온은 $30^{\circ}C$이었다. 균사 특유의 clamp connection이 관찰되었다. 옥수수에서 발생한 병징과 병원균의 균학적 특징을 조사한 결과, 이 병을 Sclerotium rolfsii Saccardo에 의한 옥수수 흰비단병으로 명명하고자 제안한다.

• 대한임상검사과학회지
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• 제42권1호
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• pp.1-15
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• 2010

Swine influenza virus (SIV) or swine-origin influenza virus (S-OIV) is endemic in swine, and classified into influenza A and influenza C but not influenza B. Swine influenza A includes H1N1, H1N2, H3N1, H3N2 and H2N3 subtypes. Infection of SIV occurs in only swine and that of S-OIV is rare in human. What human can be infected with S-OIV is called as zoonotic swine flu. Pandemic 2009 swine influenza H1N1 virus (2009 H1N1) was emerged in Mexico, America and Canada and spread worldwide. The triple-reassortant H1N1 resulting from antigenic drift was contained with HA, NA and PB1 of human or swine influenza virus, PB2 and PA polymerase of avian influenza virus, and M, NP and NS of swine influenza virus, The 2009 H1N1 enables to transmit to human and swine. The symptoms and signs in human infected with 2009 H1N1 virus are fever, cough and sore throat, pneumonia as well as diarrhea and vomiting. Co-infection with other viruses and bacteria such as Streptococcus pneumoniae can occur high mortality in high-risk population. 2009 H1N1 virus was easily differentiated from seasonal flu by real time RT-PCR which contributed rapid and confirmed diagnosis. The 2009 H1N1 virus was treated with NA inhibitors such as oseltamivir (Tamiflu) and zanamivir (Relenza) but not with adamantanes such as amantadine and rimantadine. Evolution of influenza virus has continued in various hosts. Development of a more effective vaccine against influenza prototypes is needed to protect new influenza infection such as H5 and H7 subtypes to infect to multi-organ and cause high pathogenicity.

• 한국균학회지
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• 제33권1호
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• pp.35-37
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• 2005

2002년부터 2003년까지 2년 동안 경남 거제시 학동면 조팝나무 재배농가에서 잎과 줄기에 이상증상이 심하게 발생하였다. 병징은 처음 잎에 암적갈색의 작은 둥근 반점이 많이 생기고, 줄기에 검은색 반점이 나타나며 진전됨에 따라 약간 움푹하게 들어가고 긴 타원형으로 검게 썩는다. 심하게 발생하면 병든 가지 윗부분은 말라 죽는다. 균총은 PDA배지에서 회색이고 분생포자 모양은 단세포, 원통형이며 크기는 $6{\sim}12{\times}3{\sim}5\;{\mu}m$였다. 강모의 색깔은 암갈색이고 바늘모양의 원추형이며 크기는 $23{\sim}42{\times}2{\sim}4\;{\mu}m$이었다. 균사생육 최적온도는 $30^{\circ}C$였다. 분리된 병원균으로 병원성을 검정한 결과, 자연 감염된 병징과 똑같았다. 이상의 결과를 가지고 본 병해를 Colletotrichum gloeosporioides에 의한 조팝나무 탄저병으로 명명할 것을 제안한다.

• Journal of Microbiology
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• 제45권4호
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• pp.291-296
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• 2007

Insoluble glucans synthesized by Streptococcus mutans enhance the pathogenicity of oral biofilm by promoting the adherence and accumulation of cariogenic bacteria on the surface of the tooth. The objective of this study was to investigate the effect of Leuconostoc spp. on the in vitro formation of S. mutans biofilm. Three strains, Leuconostoc gelidum A TCC 49366, Leuconostoc mesenteroides ssp. cremoris A TCC 19254 and Leuconostoc mesenteroides ssp. mesenteroides ATCC 8293, were used in this study. They exhibited profound inhibitory effects on the formation of S. mutans biofilm and on the proliferation of S. mutans. The water-soluble polymers produced from sucrose were most strongly produced by L. gelidum, followed by L. mesenteroides ssp. cremoris and L. mesenteroides ssp. mesenteroides. The mean wet weights of the artificial biofilm of S. mutans were also significantly reduced as a result of the addition of the water-soluble polymers obtained from Leuconostoc cultures. According to the results of thin-layer chromatographic analysis, the hydrolysates of the water-soluble polymers produced by Leuconostoc were identical to those of dextran T-2000, forming predominately ${\alpha}-(1-6)$ glucose linkages. These results indicate that dextran-producing Leuconostoc strains are able to inhibit the formation of S. mutans biofilm in vitro.

• Journal of Microbiology and Biotechnology
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• 제17권2호
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• pp.234-243
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• 2007

Vibrio vulnificus is an opportunistic pathogen that causes septicemia in humans. To identify the genes associated with its pathogenicity, in vivo expression technology (IVET) was used to select genes specifically expressed in a host, yet not significantly in vitro. Random lacZ-fusions in the genome of V vulnificus strain MO6-24/O were constructed using an IVET vector, pSG3, which is a suicide vector containing promoterless-aph and -lacZ as reporter genes. A total of ${\sim}18,000$ resulting library clones were then intraperitoneally injected into BALB/c mice using a colony forming unit (CFU) of $1.6{\times}10^6$. Two hours after infection, kanamycin was administered at $200{mu}g$ per gram of mouse weight. After two selection cycles, 11 genes were eventually isolated, which were expressed only in the host. Among these genes, VV20781 and VV21007 exhibiting a homology to a hemagglutinin gene and tolC, respectively, were selected based on having the highest frequency. When compared to wild-type cells, mutants with lesions in these genes showed no difference in the rate of growth rate, yet a significant decrease in cytotoxicity and the capability to form a biofilm.

• 한국균학회지
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• 제42권4호
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• pp.353-356
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• 2014

2013년 8월, 경기도 화성시에 위치한 과수원에서 체리 과실에 회색의 포자 덩어리가 발생하는 잿빛무늬병 증상이 관찰되었다. 과실에 갈색의 수침상 원형 병반이 나타나고, 진전되면 과실 전체가 부패하였다. 부패된 과실에 회갈색 내지 연회색의 포자덩어리가 관찰되었다. 병든 체리 과실에서 2개의 Monilinia균을 분리하여 균학적 특성을 조사한 결과 M. fructicola로 동정되었다. 이러한 결과를 확인하기 위하여 ITS 영역의 염기서열을 분석하였다. 그 결과, 분리균은 모두 M. fructicola로 확인되었다. 체리 과실을 상처구와 무상처구로 구분하고, 포자현탁액을 접종하여 병원성을 확인한 결과, 접종 7일 후 상처의 유무에 관계없이 분리균을 접종한 부위에서 수침상의 둥근 병반이 관찰되었다. 따라서 본 병을 Monilinia fructicola에 의한 체리잿빛무늬병으로 명명하며, 이 균에 의한 잿빛무늬병의 발생을 국내 최초로 보고한다.

• The Plant Pathology Journal
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• 제21권4호
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• pp.317-321
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• 2005

Since 2000 severe rots on aerial and underground parts of paprika (Capsicum annum L.) has occurred in most surveyed glasshouses throughout the country. A total of 56 isolates of a fungus were consistently isolated from various plant parts such as fruit, stem, branch, and root collected from 16 farms in five provinces. Anamorph stage of the fungus was identified as Fusarium solani based on its morphological characteristics. However, the fungus readily produced a sexual structure of perithecia on infected plant tissues and on agar media. Since the fungus formed abundant perithecium by a single isolate, it was considered as a homothallic strain of Nectria haematococca, the teleomorph of F. solani. Irregularly globose perithecia with orange to red color formed sparsely to gregariously on dead tissues of fruits and basal stems at the late infection stage, which is a diagnostic sign for the disease. Perithecia ranged from 125 to 220 ${\mu}m$ in diameter varied among isolates. Asci enveloping eight ascospores were cylindrical and measured 60-80x8-12 ${\mu}m$. Ellipsoid to obovate ascospores are two-celled and measured 11-18x4-7 ${\mu}m$. Ascospores were hyaline, slightly constricted at the central septum, and revealed longitudinal striations that is characteristic of the species. This fungus that has never been reported in Korea has previously become a threat to paprika cultivation because of its strong pathogenicity and nationwide distribution.