• Korean Journal of Microbiology
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• v.46 no.1
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• pp.104-108
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• 2010

We describe the construction of derivatives of wild type and mutant lrp genes that encode 6XHis-tag Lrps. These derivatives of wild type and mutant Lrp could be useful for in vitro studies including Lrp conformational changes. We show that 6XHis-tag Lrp wild type and 6XHis-tag Lrp R145W bind with similar patterns in vitro to 21 bp duplex DNA containing the consensus sequences of Lrp sites of upstream of the ilvIH operon. In addition, we report here the 6XHis-tag Lrp R145W is useful to investigate the conformational changes of Lrp in solution by using its own intrinsic fluorescence characteristics.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.48 no.5
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• pp.731-738
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• 2015

Nematode infection in the epithelial tissue of cultured rockfish Sebastes schlegeli was first reported in 2012. Since then, nematode infections have caused serious economic losses in rockfish aquaculture on the west coast of Korea. Taxonomic and life cycle information for this parasite are currently unknown. In this study, 18S rRNA and cytochrome c oxidase subunit I (COI) genes were used for molecular identification and polymerase chain reaction (PCR) to detect the invisible stages of this parasite. Nucleotide sequences of the 18S rRNA of the rockfish nematode showed 98% identity with that of Philometra morii. Therefore, this rockfish nematode was classified to the Philometridae family. However, we could not identify it to genus level using 18S rRNA. Its COI nucleotide sequences shared 85% and 82% identities with those of Bursaphelenchus sinensis and Philometra overstreeti, respectively. In addition, two gene-specific primer sets were designed based on the 18S rRNA gene to detect the intermediate host and nematode larvae. These primers were specific to this rockfish nematode without cross-reacting to other pathogens. The detection limit of the PCR assay using these primers was 1,000 copies of nematoda plasmid DNA. Therefore, the PCR assay described here is suitable for the detection of nematode DNA within rockfish. In addition, this PCR assay could be used to detect nematode larvae and the intermediate host.

• Journal of Microbiology and Biotechnology
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• v.18 no.5
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• pp.837-844
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• 2008

Glucose (xylose) isomerases from Streptomyces sp. have been used for the production of high fructose corn syrup for industrial purposes. An 11-kb DNA fragment containing the xyl gene cluster was isolated from Streptomyces lividans TK24 and its nucleotide sequences were analyzed. It was found that the xyl gene cluster contained a putative transcriptional repressor (xylR), xylulokinase (xylB), and xylose isomerase (xylA) genes. The transcriptional directions of the xylB and xylA genes were divergent, which is consistent to those found in other streptomycetes. A gene encoding XylR was located downstream of the xylB gene in the same direction, and its mutant strain produced xylose isomerase regardless of xylose in the media. The enzyme expression level in the mutant was 4.6 times higher than that in the parent strain under xylose-induced condition. Even in the absence of xylose, the mutant strain produce over 60% of enzyme compared with the xylose-induced condition. Gel mobility shift assay showed that XylR was able to bind to the putative xyl promoter, and its binding was inhibited by the addition of xylose in vitro. This result suggested that XylR acts as a repressor in the S. lividans xylose operon.

• Korean Journal of Plant Resources
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• v.19 no.1
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• pp.54-58
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• 2006

The genetic analyses of Acanthopanax senticosus Harms from Korea, China and Russia, were made by comparing the internal transcribed spacer (ITS) sequences of the nuclear ribosomal DNA. The ITS region of A. senticosus was amplified by polymerase chain reaction (PCR) using the universal primers and then directly sequenced. The length of the ITS region including 162 bp 5.85 rRNA gene ranged from 608 bp (for Korean and Chinese) to 611 bp (for Russian). The G+C content of ITS region were 60.20% for Korean and Chinese plants and 60.06% for Russian plants. Sequence comparisons indicated that ITS regions of A. senticosus from Korea and China were identical, whereas the ITS sequence of A. senticosus from Russia showed 99.2% homology with the plants from Korea. Variation in sequences were attributable to 5 bp substitution such as transversion or insertion events. These results suggested that A. senticosus Harms from Korea and China were closely related in phylogenetic relationship compared to Russian. In addition, A. senticosus Harms were more similar to Kalopanax pictus than A. sessiliflorus in their ITS sequences.

• 한국문화재보존과학회:학술대회논문집
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• 2005.11a
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• pp.252-254
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• 2005

박물관 수장고와 전시실 내의 유기물 문화재는 실내공기에 부유하고 있는 먼지와 곰팡이로 인해 생물적 피해를 받는다. 미생물로 인한 피해를 줄이기 위하여 박물관에서는 환경 조절법을 시행하거나 수장고와 전시실 내에 보존약제를 놓거나 또는 훈증 처리를 통한 방균 방제처리를 시행하고 있다. 미생물의 발생은 문화재 표면의 착색, 재질 분해, 변질 등을 야기한다. 본 연구는 위에 제시된 방법 외에 공기청정기를 이용하여 실내 부유 미생물 수를 줄여 유기물 문화재의 피해를 줄일 수 있는지를 알아보았다. 국립문화재연구소 내 생물과학실의 실험실 한 곳을 임의로 지정하여 공기청정기를 설치하기 전 곰팡이의 수를 측정하고, 공기청정기를 설치한 후의 곰팡이 변화를 4일 간격으로 측정하였다. 또한, 공기 중의 ???r성분 분석을 위하여 가스크로마토그래피(Gas Chromatography)를 이용하였다. 측정결과 곰팡이의 수는 대체적으로 감소하였으며, 채취한 곰팡이를 배양하여 동정을 실시하였다. 곰팡이 동정은 현미경을 통한 형태학적 분류와 ITS(Internal Transcribed Sequence)를 이용한 rDNA(Ribosomal DNA) PCR(Polymerase Chain Reaction)분석 두 가지 방법을 이용하여 동정하였다.

• Mycobiology
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• v.40 no.1
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• pp.14-19
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• 2012

A $Mariannaea$ fungus was isolated during investigation of an elm tree infested with unidentified beetles. Based on morphological characteristics and molecular analysis of the internal transcribed spacer rDNA sequence, the fungus was identified as $Mariannaea$ $elegans$ var. $elegans$. Fungal growth was better on malt extract agar than on potato dextrose agar and oatmeal agar. Optimal temperature and pH for growth of the fungus were $30^{\circ}C$ and pH 7.0, respectively. The fungus was found to have the ability to produce extracellular enzymes such as amylase, ${\beta}$-glucosidase, cellulase, and protease. This is first report on $M.$ $elegans$ var. $elegans$ in Korea.

• Mycobiology
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• v.45 no.1
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• pp.9-14
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• 2017

Most known species in the Physalacriaceae are saprotrophs that grow on decaying leaves and wood, and approximately 21 genera in the Physalacriaceae have been reported worldwide. During an ongoing survey of indigenous fungi in Korea, four specimens belonging to the Physalacriaceae were collected on Ulleung Island. These specimens were identified as three species based on morphological characteristics and molecular analysis of rDNA-internal transcribed spacer sequences. Three species in three genera were shown to be new records in Korea: Hymenopellis orientalis, Paraxerula hongoi, and Ponticulomyces orientalis. The latter two are the first records of these genera in Korea. In this study, we provide detailed morphological descriptions of these species and describe their phylogenetic position within the Physalacriaceae.

• The Korean Journal of Mycology
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• v.44 no.2
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• pp.113-117
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• 2016

The biodiversity of endophytic fungi on Thuja koraiensis in Mt. Hwaak, Seorak, and Hambaek, Korea was investigated. For the 202 isolates collected from the host trees, internal transcribed spacer rDNA region sequences-based analysis identified 32 taxa; 61.5% of the isolates belonged to Dothideomycetes, 27.0% belonged to Sordariomycetes, and 11.5% belonged to Leotiomycetes. This composition rate is somewhat different from that reported in previous studies for endophytic fungi inhabiting trees of the family Pinaceae. In particular, Phyllosticta spinarum in Dothideomycetes is a dominant species among the diverse endophytes of T. koraiensis. Therefore, further critical research is required for this species.

• The Korean Journal of Mycology
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• v.47 no.4
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• pp.313-318
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• 2019

In the present study, we isolated endophytic fungal strains from the rhizoids of the moss Funaria hygrometrica. The isolated strains were identified based on morphological characteristics and analysis of the internal transcribed spacer (ITS) and large subunit (LSU) rDNA sequence regions. Consequently, we confirmed the presence of two endophytic fungal species, Curvularia protuberata and Didymella anserina, which have not been reported in Korea previously. Here, we describe the morphological characteristics and molecular analysis results of these fungal species.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.50 no.4
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• pp.286-290
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• 2005

Ascorbate peroxidase (APX) plays a crucial role in the detoxification of hydrogen peroxide. APX activity is maintained significantly higher in the paraquat­treated leaves of the paraquat-tolerant Rehmannia glutinos. This study was conducted to understand structural and regulatory characteristics of APX gene in R. glutinosa. A putative APX cDNA clone (RgAPX1) was isolated from a leaf cDNA library using a partially sequenced expressed sequence tag clone. RgAPX1 is consisted of 1148 bp nucleotides and contains an open reading frame encoding a 250 amino acid-long polypeptide. Deduced RgAPX1 amino acid sequence shares higher sequence similarity to cytosolic APXs. RgAPX1. expression was higher in the leaf than in the flower and root. Southern blot result indicates the presence of one or two RgAPX1-related genes in R. glutinosa genome. RgAPX1 transcription was affected differentially by various stresses and phytohormone. The results indicate that RgAPXl is constitutively expressed in most tissues and its expression is modulated for the immediate and efficient detoxification of $H_2O_2$ under normal and stress conditions.