• Mycobiology
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• v.45 no.1
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• pp.39-43
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• 2017

Leaf spot disease on black chokeberry (Aronia melanocarpa) was observed at several locations in Korea during 2014-2015. Leaf spots were distinct, scattered over the leaf surface and along the leaf border, subcircular to irregular and brown surrounded by a distinct dark color, and were expanded and coalesced into irregularly shaped lesions. Severely infected leaves became dry and fell off eventually. The causative agent was identified as Pseudocercospora pyricola. Morphological observations and phylogenetic analyses of multiple genes, including internal transcribed spacer, translation elongation factor 1-alpha, actin, and the large subunit ribosomal DNA were conducted. The pathogenicity test was conducted twice yielding similar results, fulfilling Koch's postulates. To our knowledge, this is the first report on P. pyricola infection of A. melanocarpa globally.

• ALGAE
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• v.29 no.4
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• pp.267-277
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• 2014

Green tides occur every year in the Yellow Sea (YS), and numerous investigations are proceeding on various aspects of the phenomenon. We have identified bloom-forming species collected from diverse locations in the YS using morphological traits and the chloroplast gene for the large subunit of ribulose-1,5-bisphosphate carboxylase (rbcL). Morphological and rbcL sequence data analyses characterized the blooming species on both sides of the YS as belonging to the Ulva linza-procera-prolifera (LPP) complex clade or U. prolifera of earlier reports. However, U. procera within the LPP complex must be regarded as synonym of U. linza. Moreover, U. prolifera in free-floating samples collected from the Qingdao coast in 2009 was clearly in a distinct clade from that of the blooming species. Therefore, U. linza is the main green tide alga in the YS and has the procera-morphology. The green drift mats in the southeastern part of the YS (southwest sea of Korea) consisted predominantly of U. linza and rarely of U. compressa or U. prolifera.

• Microbiology and Biotechnology Letters
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• v.43 no.3
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• pp.241-248
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• 2015

Tuak is a traditional alcoholic beverage, one of the most widely known in the North Sumateran region of Indonesia. It is produced by a spontaneous fermentation process through the application of one or more several kinds of wood bark or root, called raru (Xylocorpus wood bark or a variety of forest mangosteen), into the sap water of sugar palm (Arenga pinnata) for 2−3 days. In this research, yeast that are potentially useful for ethanol production was isolated from Tuak and identified. Based on analysis of D1/D2 domain sequence of LSU (large subunit) rRNA genes, those isolated yeast strains, HT4, HT5, and HT10 were identified as Candida tropicalis. Fermentation test of these C. tropicalis isolates displayed an ability to produce 6.55% (v/v) and 4.58% ethanol at 30℃ and 42℃, respectively. These results indicated C. tropicalis isolates more rapidly utilize glucose and obtain higher levels of the production of ethanol at the higher temperature of 42℃ than S. cerevisiae, a common yeast used for bioethanol fermentation.

• BMB Reports
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• v.38 no.1
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• pp.28-33
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• 2005

A gene coding a novel isoform of carbamyl phosphate synthetase I (CPS1) was cloned from a human testicular library. As shown by cDNA microarray hybridization, this gene was expressed at a higher level in human adult testes than in fetal testes. The full length of its cDNA was 3831 bp, with a 3149 bp open reading frame, encoding a 1050-amino-acid protein. The cDNA sequence was deposited in the GenBank (AY317138). Sequence analysis showed that it was homologous to the human CPS1 gene. The putative protein contained functional domains composing the intact large subunit of carbamoyl phosphate synthetase, thus indicated it has the capability of arginine biosynthesis. A multiple tissue expression profile showed high expression of this gene in human testis, suggesting the novel alternative splicing form of CPS1 may be correlated with human spermatogenesis.

• BMB Reports
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• v.31 no.4
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• pp.307-327
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• 1998

Cytochrome c peroxidase (CcP) is a yeast mitochondrial enzyme which catalyzes the reduction of hydrogen peroxide to water using two equivalents of ferrocytochrome c. The CcP/cytochrome c system has many features which make it a very useful model for detailed investigation of heme protein structure/function relationships including activation of hydrogen peroxide, protein-protein interactions, and long-range electron transfer. Both CcP and cytochrome c are single heme, single subunit proteins of modest size. High-resolution crystallographic structures of both proteins, of one-to-one complexes of the two proteins, and a number of active-site mutants are available. Site-directed mutagenesis studies indicate that the distal histidine in CcP is primarily responsible for rapid utilization of hydrogen peroxide implying significantly different properties of the distal histidine in the peroxidases compared to the globins. CcP and cytochrome c bind to form a dynamic one-to-one complex. The binding is largely electrostatic in nature with a small, unfavorable enthalpy of binding and a large positive entropy change upon complex formation. The cytochrome c-binding site on CcP has been mapped in solution by measuring the binding affinities between cytochrome c and a number of CcP surface mutations. The binding site for cytochrome c in solution is consistent with the crystallographic structure of the one-to-one complex. Evidence for the involvement of a second, low-affinity cytochrome c-binding site on CcP in long-range electron transfer between the two proteins is reviewed.

• Fisheries and Aquatic Sciences
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• v.7 no.3
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• pp.122-129
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• 2004

Harmful Cochlodinium polykrikoides is a notorious harmful algal bloom (HAB) species that is causing mass mortality of farmed fish along the Korean coast with increasing frequency. We analyzed the sequence of the large subunit (LSD) rDNA D1-D3 region of C. polykrikoides and conducted phylogenetic analyses using Bayesian inference of phylogeny and the maximum likelihood method. The molecular phylogeny showed that C. polykrikoides had the genetic relationship to Amphidinium and Gymnodinium species supported only by the relatively high posterior probabilities of Bayesian inference. Based on the LSU rDNA sequence data of diverse dinoflagellate taxa, we designed the C. polykrikoides-specific PCR primer set, CPOLY01 and CPOLY02 and developed PCR detection assays for its sensitive, accurate HAB monitoring. CPOLY01 and CPOLY02 specifically amplified C. polykrikoides and did not cross-react with any dinoflagellates tested in this study or environmental water samples. The effective annealing temperature $(T_{p})$ of CPOLY01 and CPOLY02 was $67^{\circ}C$. At this temperature, the conventional and nested PCR assays were sensitive over a wide range of C. polykrikoides cell numbers with detection limits of 0.05 and 0.0001 cells/reaction, respectively.

• The Korean Journal of Mycology
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• v.44 no.1
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• pp.51-56
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• 2016

Diverse endophytic fungi were isolated from surface-sterilized leaves of three species of conifers inhabiting various sites in Korea: Abies nephrolepis, Pinus koraiensis and Taxus cuspidate. The isolates were identified based on morphological characteristics and sequences analysis of both internal transcribed spacer and large subunit regions of rDNA. In this paper, we report on five previously unreported species of endophytic fungi isolated from conifers: Biscogniauxia maritime, Nemania diffusa, Pezicula carpinea, Phomopsis juglandina and Sydowia polyspora.

• ALGAE
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• v.17 no.3
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• pp.135-144
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• 2002

Scytosiphonaceae is an acetocarpalean brown algal family, that is a recent focus of synstematics and marine biodiversity. We describe Petalonia zosterifolia and Scytosiphon gracilis from Korea for the first time. P. zosterifolia occurred on the East coast, and had flat, linear and solid thalli. S. gracilis was found in Jeju, and had cylindircal to flat and hol-low thalli. However, these two species are so similar that it is difficult to identify by morphology alone. In order to determine if the nuclear DNA reveals the distinctness of both species and to know their phylogenies, the ITS region sequences were newly detrmined in 22 samples of P. zosterifolia, Scytosiphon gracilis, and other three members of the genera from Korea. We found 0.12% variation among samples of P. zosterifolia from different locations, and no variation between S. gracilis samples from diferent years, but extensive interspecific divergences (13.62-22.83%) of each species to other members in Petalonia and Scytosiphon . The ITS sequence dta consistently showed a close relationship between P. zosterifolia and S. gracilis. This result is congruent with morphology and with the published data of plastid rbc and partial nrDNA large subunit gene sequences, and suggests that P. zosterifolia and S. gracilis might have diverged from the most recent common ancestor.

• ALGAE
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• v.33 no.2
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• pp.167-180
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• 2018

Benthic diatoms are ubiquitous in tidal flats and play major roles in maintaining coastal ecosystems. Spatio-temporal variations in diatom diversity have not been well-studied, mainly because of difficulties in morphological identification and the lack of appropriate genetic tools. To overcome these problems, we used the gene encoding the ribulose bisphosphate carboxylase large-subunit (rbcL) as a molecular marker, and sequenced these genes with the aid of the MiSeq platform. In this manner, we explored the genetic diversity of benthic diatoms in tidal flats of Guenso Bay on the west coast of Korea; differences in the spatial distributions of benthic diatoms were evident. The diatom communities were dominated by Nitzschia, Navicula, and Amphora; their relative distributions were affected by the sand proportion, grain size, and air exposure time. Our results suggest that meta-barcoding of the rbcL gene and next-generation sequencing can be used to explore the diversity of benthic diatoms.

• Animal Systematics, Evolution and Diversity
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• v.27 no.2
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• pp.159-163
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• 2011

DNA barcoding of Bryozoa or "moss animals" has hardly advanced and lacks reference sequences for correct species identification. To date only a small number of cytochrome c oxidase subunit I (COI) sequences from 82 bryozoan species have been deposited in the National Center for Biotechnology Information (NCBI) GenBank and Barcode of Life Data Systems (BOLD). We here report COI data from 53 individual samples of 29 bryozoan species collected from Korean seawater. To our knowledge this is the single largest gathering of COI barcode data of bryozoans to date. The average genetic divergence was estimated as 23.3% among species of the same genus, 25% among genera of the same family, and 1.7% at intraspecific level with a few rare exceptions having a large difference, indicating a possibility of presence of cryptic species. Our data show that COI is a very appropriate marker for species identification of bryozoans, but does not provide enough phylogenetic information at higher taxonomic ranks. Greater effort involving larger taxon sampling for the barcode analyses is needed for bryozoan taxonomy.