• 한국버섯학회지
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• 제14권3호
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• pp.75-80
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• 2016

국내에서 분리한 신규 P linteus KACC93057P의 자실체의 형태적 특성을 육안적 으로 관찰한 결과 대가없이 기주부착형으로 자실체표면은 단단한 목질형태 (hardy woody) 로 동심원으로 윤층대 (zonate)와 홈을 형성하고 담갈색을 띠고 있었다. 자실체 뒷면 테두리는 진황색, 내부는 담황갈색을 띠며 현미경 미세구조를 관찰한 결과 관공은 원형또는 각진형이며, 관공구는 5-7 per mm크기로 나타났다. hyphal system은 2분지형이며 포자는 $4.5-6{\times}4-5{\mu}m$크기로 난형또는 유구형 담갈색을 띠어 P linteus와 유사한 특성을 보였다. YGMA배지상에서 KACC93057P는 $25-30^{\circ}C$가 최적온도로 균사체 성장률이 장수상황과 고려상황에 비하여 10-25% 높았으며 균사밀도가 다른 균주보다 현저히 높게 나타났다. ITS-rDNA염기서열비교결과 96% 이상의 상동성으로 I. lonicericola, I. linteus, I. baumii와 근연관계를 형성 하였다.

• 한국균학회지
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• 제45권2호
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• pp.145-152
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• 2017

국내에서 밤나무 흰가루병균은 1958년에 Microsphaera alni로 처음 기록되었다. 1988년에는 이 흰가루병균의 형태적 특징과 기주를 고려하여 M. sinensis로 동정되었다. 이 학명은 '식물명명에 관한 국제규약'의 규칙에 따라 2006년에 E. castaneigena로 변경되었다. 그럼에도 불구하고, 국내의 밤나무 흰가루병균의 형태적 특징 및 분자적 분석에 의한 분류학적 재검토가 이루어지지 않았다. 본 연구에서는 고려대학교 진균표본실에 보존된 34점의 밤나무 흰가루병균 시료를 대상으로 수행되었다. 무성세대와 유성세대의 형태적 특징을 현미경으로 관찰하고 ITS 영역의 염기서열을 분석함으로써, 한국의 밤나무 흰가루병균은 E. castaneigena로 확인되었다. 또한, 염기서열 분석을 통하여 E. castaneigena와 밤나무 유래의 E. alphitoides는 계통학적으로 근연 관계임을 제시하였다.

• 한국미생물·생명공학회지
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• 제39권3호
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• pp.287-293
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• 2011

본 연구는 터널표면의 퇴색 및 변색을 초래할 것으로 생각되는 주요 균사형진균을 결정하고, 그 진균을 방제하기 위해 부근 장소에서 분리된 세균들이 항진균 길항능을 가지는 동시에 탄산칼슘 형성을 확인하였다. 이 균주를 이용하여 모르타르에 적용했을 때 항진균 및 압축강도 증진효과를 가진 세균자원을 확보하는데 그 목적이 있다. 터널내의 오염된 지역에서 시료를 취하여 다양한 배지를 이용하여 곰팡이, 효모 및 세균을 분리하였고, 분리된 진균의 ITS-5.8S rRNA gene sequene와 세균의 16s rDNA sequence를 이용해 부분동정을 실시했다. 분리된 미생물의 터널 내 분포를 결정하였으며, 분리된 세균 5종의 탄산칼슘 형성능력을 확인하였다. 터널내 오염지역에서 가장 널리 분포하는 곰팡이인 C. sphaerospermum KNUC253 과 감수성 시험에 널리 이용되는 공시균인 A. niger KCTC6906을 대상으로 항진균 시험을 실시하였다. 터널 분리세균 5종 모두 urea-$CaCl_2$ 고체배지에서 배양했을 때 콜로니 주변부 에서 종 특이적으로 다양한 크기와 형태의 탄산칼슘을 형성함을 확인하였다. 그 중 B. aryabhatti KNUC205는 감수성 곰팡이를 대상으로 뛰어난 항진균 길항능을 보였다.

• 한국미생물·생명공학회지
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• 제48권2호
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• pp.167-178
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• 2020

Lipase-producing fungi have been isolated from environments containing lipids. The non-dairy creamer industrial waste has a high amount of lipids so it is a potential source for the isolation of lipase-producing fungi. However, the study of fungi that secrete lipase from this industrial waste has not been reported. The purpose of this study was to obtain lipase-producing filamentous fungi from non-dairy creamer industrial waste. Mineral salt and potato dextrose agar were used as media for the isolation process. The qualitative screening was conducted using phenol red agar medium and the quantitative screening using broth medium containing glucose and olive oil. Isolates producing the highest amounts of lipase were identified with molecular methods. We found that 5 out of 19 isolated filamentous fungi are lipase producers. Further analysis showed that isolate Ms.11 produced the highest amount of lipase compared to others. Based on ITS sequence Ms.11 was identified as Aspergillus aculeatus. The lipase activity in medium containing 1% glucose + 1% olive oil at pH 7.0 and 30℃ after 96 and 120 h of incubation was 5.13 ± 0.30 U/ml and 5.22 ± 0.59 U/ml, respectively. The optimum lipase activity was found at pH 7.0, 30℃ and using methanol or ethanol in the reaction tube. Lipase was more stable at 20-30℃ and maintained 85% of its activity. It was concluded that isolate Ms.11 is a potential source of lipase that catalyzes transesterification reactions. Further studies are required to optimize lipase production to make the strain suitable for industry purposes.

• 식물병연구
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• 제25권1호
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• pp.33-37
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• 2019

2016년부터 2018년까지 제주도내 농가포장에서 재배되고 있는 콜라비에 뿌리혹병 지속적으로 발생(최고발병률 27.2%)했다. 초기 감염은 뿌리털 부분이 정상주 뿌리털에 비해 비대했으며, 병이 진전되면서 뿌리 중심부에 혹이 형성되고, 잎이 시들고 끝이 누렇게 변했다. P. brassicae 휴면포자 현탁액을 이용한 병원성 검정결과 접종 50일 후에 병원성을 나타냈다. 병원균은 콜라비 세포조직 안에 빈 곳 없이 무수히 많은 휴면포자를 형성하며, 휴면포자는 단세포로 무색, 원형 또는 타원형, 크기는 직경 $3-5{\mu}m$이다. 콜라비 뿌리혹병원균의 ITS rDNA 염기서열 분석, 계통수 작성 결과 P. brassicae로 동정했다. 따라서 균학적 특징, 병원성 검정, ITS rDNA 염기서열 비교분석 등의 결과를 바탕으로 이 병은 우리나라에서 지금까지 보고되지 않은 'Plasmodiophora brassicae에 의한 콜라비 뿌리혹병'으로 명명하고자 한다.

• Journal of Veterinary Science
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• 제24권3호
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• pp.38.1-38.12
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• 2023

Background: Poor disease management and irregular vector control could predispose sheltered animals to disease such as feline Bartonella infection, a vector-borne zoonotic disease primarily caused by Bartonella henselae. Objectives: This study investigated the status of Bartonella infection in cats from eight (n = 8) shelters by molecular and serological approaches, profiling the CD4:CD8 ratio and the risk factors associated with Bartonella infection in shelter cats. Methods: Bartonella deoxyribonucleic acid (DNA) was detected through polymerase chain reaction (PCR) targeting 16S-23S rRNA internal transcribed spacer gene, followed by DNA sequencing. Bartonella IgM and IgG antibody titre, CD4 and CD8 profiles were detected using indirect immunofluorescence assay and flow cytometric analysis, respectively. Results: B. henselae was detected through PCR and sequencing in 1.0% (1/101) oral swab and 2.0% (1/50) cat fleas, while another 3/50 cat fleas carried B. clarridgeiae. Only 18/101 cats were seronegative against B. henselae, whereas 30.7% (31/101) cats were positive for both IgM and IgG, 8% (18/101) cats had IgM, and 33.7% (34/101) cats had IgG antibody only. None of the eight shelters sampled had Bartonella antibody-free cats. Although abnormal CD4:CD8 ratio was observed in 48/83 seropositive cats, flea infestation was the only significant risk factor observed in this study. Conclusions: The present study provides the first comparison on the Bartonella spp. antigen, antibody status and CD4:CD8 ratio among shelter cats. The high B. henselae seropositivity among shelter cats presumably due to significant flea infestation triggers an alarm of whether the infection could go undetectable and its potential transmission to humans.

• ALGAE
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• 제38권1호
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• pp.1-22
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• 2023

An enormous body of research is focused on finding ways to commercialize carotenoids produced by the unicellular green alga, Haematococcus, often without the benefit of a sound phylogenetic assessment. Evidence of cryptic diversity in the genus means that comparing results of pigment studies may be confounded by the absence of a phylogenetic framework. Moreover, previous work has identified unnamed strains that are likely candidates for species status. We reconstructed the phylogeny of an expanded sampling of Haematococcus isolates utilizing data from nuclear ribosomal markers (18S rRNA gene, 26S rRNA gene, internal transcribed spacer [ITS]-1, 5.8S rRNA gene, and ITS-2) and the rbcL gene. In addition, we gathered morphological, ultrastructural and pigment data from key isolates of Haematococcus. Our expanded data and taxon sampling support the concept of a new species, H. privus, found exclusively in North America. Despite overlap in numerous morphological traits, results indicate that ratios of protoplast length to width and akinete diameter may be useful for discriminating Haematococcus lineages. High growth rate and robust astaxanthin yield indicate that H. rubicundus (SAG 34-1c) is worthy of additional scrutiny as a pigment source. With the description of H. privus, the evidence supports the existence of at least five, species-level lineages in the genus. Our phylogenetic assessment provides the tools to frame future pigment investigations of Haematococcus in an updated evolutionary context. In addition, our investigation highlighted open questions regarding polyploidy and sexuality in Haematococcus which demonstrate that much remains to be discovered about this green flagellate.

• The Plant Pathology Journal
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• 제40권2호
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• pp.171-191
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• 2024

Identification of Helicotylenchus species is very challenging due to phenotypic plasticity and existence of cryptic species complexes. Recently, the use of rDNA barcodes has proven to be useful for identification of Helicotylenchus. Molecular markers are a quick diagnostic tool and are crucial for discriminating related species and resolving cryptic species complexes within this speciose genus. However, DNA barcoding is not an error-free approach. The public databases appear to be marred by incorrect sequences, arising from sequencing errors, mislabeling, and misidentifications. Herein, we provide a comprehensive analysis of the newly obtained, and published DNA sequences of Helicotylenchus, revealing the potential faults in the available DNA barcodes. A total of 97 sequences (25 nearly full-length 18S-rRNA, 12 partial 28S-rRNA, 16 partial internal transcribed spacer [ITS]-rRNA, and 44 partial cytochrome c oxidase subunit I [COI] gene sequences) were newly obtained in the present study. Phylogenetic relationships between species are given as inferred from the analyses of 103 sequences of 18S-rRNA, 469 sequences of 28S-rRNA, 183 sequences of ITS-rRNA, and 63 sequences of COI. Remarks on suggested corrections of published accessions in GenBank database are given. Additionally, COI gene sequences of H. dihystera, H. asiaticus and the contentious H. microlobus are provided herein for the first time. Similar to rDNA gene analyses, the COI sequences support the genetic distinctness and validity of H. microlobus. DNA barcodes from type material are needed for resolving the taxonomic status of the unresolved taxonomic groups within the genus.

• 한국균학회지
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• 제43권1호
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• pp.71-76
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• 2015

수생식물 샘플은 낙동강과 금호강이 만나는 달성습지에서 자라풀을 채집하였다. 자라풀의 뿌리에서 내생균류를 분리하고 형태가 다른 균주를 관찰하여 최종적으로 16개 균주를 선발하였다. 내생균류의 배양여과액은 식물생장촉진활성 검정을 위하여 난장이벼에 처리하여 스크리닝하였으며, HD1008 균주가 식물생장촉진활성이 가장 높은 것으로 확인되었다. HD1008 균주의 배양여과액을 HPLC와 GC/MS-SIM을 이용하여 분석하였고, HD1008 균주가 식물호르몬인 지베렐린 $GA_1$ (1.2 ng/100 mL)과 $GA_4$ (5 ng/100 mL) 를 생산하는 것을 정량분석을 통하여 확인하였다. 또한, HD1008균주의 beta-tubulin 유전자 염기서열을 이용하여 동정에 이용하였으며, 분자적인 방법과 형태적인 방법으로 관찰하였을 때, 지베렐린을 생산하는 새로운 P. trzebinskii로 동정되었다.

• Parasites, Hosts and Diseases
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• 제51권6호
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• pp.657-662
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• 2013

Freshwater snails of the family Lymnaeidae play an important role in the transmission of fascioliasis worldwide. In Vietnam, 2 common lymnaeid species, Lymnaea swinhoei and Lymnaea viridis, can be recognized on the basis of morphology, and a third species, Lymnaea sp., is known to exist. Recent studies have raised controversy about their role in transmission of Fasciola spp. because of confusion in identification of the snail hosts. The aim of this study is, therefore, to clarify the identities of lymnaeid snails in Vietnam by a combination of morphological and molecular approaches. The molecular analyses using the second internal transcribed spacer (ITS2) of the nuclear ribosomal DNA clearly showed that lymnaeids in Vietnam include 3 species, Austropeplea viridis (morphologically identified as L. viridis), Radix auricularia (morphologically identified as L. swinhoei) and Radix rubiginosa (morphologically identified as Lymnaea sp.). R. rubiginosa is a new record for Vietnam. Among them, only A. viridis was found to be infected with Fasciola spp. These results provide a new insight into lymnaeid snails in Vietnam. Identification of lymnaeid snails in Vietnam and their role in the liver fluke transmission should be further investigated.