• Mycobiology
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• 제46권2호
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• pp.101-113
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• 2018

Lichen genus Stereocaulon (Schreb.) Hoffm is distributed throughout the world. Although 15 Stereocaulon species have been recorded in Korea, no detailed taxonomic or revisionary research has been conducted for nearly two decades. In this study, we collected 260 putative Stereocaulon spp. samples and identified the species based on morphological, chemical, and molecular characteristics. From the collected samples, 10 species of Stereocaulon were identified, nine of which had already been reported, although this was the first report for the tenth, S. octomerellum Hue, in Korea. General characteristics of Stereocaulon spp. include coralloid phyllocladia and tubercular cephalodia; however, the specimen first collected in Korea was a rare species with tomentum on the pseudopodetia. The specimen of S. octomerellum is characterized by the presence of a primary thallus, granule to short coralloid phyllocladia, and pseudopodetia up to 1 cm in size, with tubercular cephalodia. To determine the phylogeny of the specimens, we compared the ITS sequences of ribosomal DNA and the b-tubulin gene sequences. Phylogenetic analysis showed that the Korean Stereocaulon species were monophyletic and placed in the previous phylogenetic classification. Species of S. intermedium and S. exutum, however, were polyphyletic, and are morphologically variable and widespread species. Overall, we present here detailed morphological and chemical descriptions of each species identified and a revised key of all known Stereocaulon species in South Korea.

• Parasites, Hosts and Diseases
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• 제52권5호
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• pp.471-478
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• 2014

Trichomonad species inhabit a variety of vertebrate hosts; however, their potential zoonotic transmission has not been clearly addressed, especially with regard to human infection. Twenty-one strains of trichomonads isolated from humans (5 isolates), pigs (6 isolates), rodents (6 isolates), a water buffalo (1 isolate), a cow (1 isolate), a goat (1 isolate), and a dog (1 isolate) were collected in Indonesia and molecularly characterized. The DNA sequences of the partial 18S small subunit ribosomal RNA (rRNA) gene or 5.8S rRNA gene locus with its flanking regions (internal transcribed spacer region, ITS1 and ITS2) were identified in various trichomonads; Simplicimonas sp., Hexamastix mitis, and Hypotrichomonas sp. from rodents, and Tetratrichomonas sp. and Trichomonas sp. from pigs. All of these species were not detected in humans, whereas Pentatrichomonas hominis was identified in humans, pigs, the dog, the water buffalo, the cow, and the goat. Even when using the high-resolution gene locus of the ITS regions, all P. hominis strains were genetically identical; thus zoonotic transmission between humans and these closely related mammals may be occurring in the area investigated. The detection of Simplicimonas sp. in rodents (Rattus exulans) and P. hominis in water buffalo in this study revealed newly recognized host adaptations and suggested the existence of remaining unrevealed ranges of hosts in the trichomonad species.

• 한국균학회지
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• 제47권4호
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• pp.291-301
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• 2019

선충 포식성곰팡이는 선충 포획 기관을 만들어 선충 포획 후 양분을 섭취하는 곰팡이다. 이들 중 Arthrobotrys flagrans와A. superba에 대한 특성들 중 보고될 때 생략된 것이 있어 두 종을 토양으로 부터 분리하고 순수배양하여 추가적으로 조사하였다. 선충 종류별 포식력, 포식기관의 형태·크기, 분생포자의 형태·크기, 분생포자병의 형태, 후막포자 등을 조사하였으며, ITS rDNA 염기서열의 분자계통학적 분석을 토대로 종 동정을 실시하였다. 또한 1981년 처음으로 선충 포식성곰팡이가 국내에서 보고된 이래로 현재까지 총 21종이 발견되었으나 이들에 대한 분류 체계와 주요 식별 형질이 없는 상황이었기에 제공하였다. 이를 바탕으로 아직 연구가 많이 진행되지 않은 국내 선충 포식성곰팡이 연구에 기초자료가 될 수 있기를 기대한다.

• Mycobiology
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• 제48권3호
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• pp.195-203
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• 2020

Marine yeasts have tremendous potential in industrial applications but have received less attention than terrestrial yeasts and marine filamentous fungi. In this study, we have screened marine yeasts for amylolytic activity and identified an amylase-producing strain PH-Gra1 isolated from sea algae. PH-Gra1 formed as a coral-red colony on yeast-peptone-dextrose (YPD) agar; the maximum radial growth was observed at 22 ℃, pH 6.5 without addition of NaCl to the media. Based on the morphology and phylogenetic analyses derived from sequences of internal transcribed spacer (ITS) and a D1/D2 domain of large subunit of ribosomal DNA, PH-Gra1 was designated Sporidiobolus pararoseus. S. pararoseus is frequently isolated from marine environments and known to produce lipids, carotenoids, and several enzymes. However, its amylolytic activity, particularly the optimum conditions for enzyme activity and stability, has not been previously characterized in detail. The extracellular crude enzyme of PH-Gra1 displayed its maximum amylolytic activity at 55 ℃, pH 6.5, and 0%-3.0% (w/v) NaCl under the tested conditions, and the activity increased with time over the 180-min incubation period. In addition, the crude enzyme hydrolyzed potato starch more actively than corn and wheat starch, and was stable at temperatures ranging from 15 ℃ to 45 ℃ for 2 h. This report provides a basis for additional studies of marine yeasts that will facilitate industrial applications.

• 환경생물
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• 제17권4호
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• pp.503-512
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• 1999

한반도와 일본에 서식하는 왕거머리말(Zostera asiatica Miki, Zosteraceae)의 서식 환경에 따른 형태적인 변이를 분석하기 위해 동해연안과 일본 훗카이도에 서식하는 왕거머리말의 식물체와 서식지의 해수 및 퇴적물을 채집 분석하였다. 본 조사를 통하여 왕거머리말은 한반도 지역에서는 수심 8.5∼10 m의 개방된 만과 외해의 영향을 직접 받는 지역에서 주로 서식하며, 동해연안의 공현진리, 동호리, 그리고 영동과 칠포 지역이 왕거머리말의 새로운 자생지로 확인되었다. 그러나 일본 홋카이도의 아케시만(Akkeshi Bay)에 있어서는 한반도와는 달리 1.5∼3m의 수심이 얕은 내만에서 서식하였다. 한반도 동해 연안에서 왕거머리말의 서식지 퇴적물의 입도는 모래로 구성되었다. 한반도 동해 연안의 집단에서는 식물체의 높이가 64.0∼75.7cm, 폭 11.0∼l5.0 mm로 나타났으나, 아케시만에 서식하는 식물체 집단의 높이 187∼234 cm, 폭은 18.0∼l8.7 mm로, 후자의 경우가 훨씬 큰 것으로 나타났다. 이러한 변이에 의해 규정된 한반도 동해연안의 집단간 그리고 일본 아케시만의 집단간핵 리보소옴 DNA의 ITS 염기서열 비교 분석에 의한 유전적 차이는 없는 것으로 나타났다.

• Mycobiology
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• 제42권2호
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• pp.140-146
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• 2014

In Seoul, a majority of plant communities have undergone significant changes over the last few decades; however, how wood decay fungi have responded and adapted to the changes in vegetation remains unknown. Through an ongoing investigation of Korean indigenous fungi, ca. 300 specimens with poroid basidiocarp were collected in Seoul during 2008~2012. Morphological examination and molecular analysis using the internal transcribed spacer and nuclear large subunit ribosomal DNA region sequences helped identify 38 species belonging to 28 genera, 10 families, and 5 orders in this area. Among them, three polypores, Abundisporus pubertatis, Coriolopsis strumosa, and Perenniporia maackiae were found to be new to South Korea.

• Animal Systematics, Evolution and Diversity
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• 제26권1호
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• pp.15-19
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• 2010

The Russian ratsnake, Elaphe schrenckii, is found in Russia, China, and Korea, and is considered to be an endangered species by the Ministry of Environment in South Korea. Due to habitat loss and use in oriental medicine, their population has been severely decimated. In South Korea, two subspecies of E. schrenckii has been defined according to body color: E. s. schrenckii (blackish) and E. s. anomala (yellow-brownish). Molecular genetic studies on Elaphe schrenckii are very scarce and the taxonomy of Elaphe schrenckii subspecies is uncertain. From the present study, we attempted to identify the genetic differences of these two subspecies using species-specific microsatellites developed from the genomic library of E. schrenckii. Nine polymorphic loci were tested on 19 individuals from E. s. schrenckii (n=10) and E. s. anomala (n=9) in South Korea. The mean number of alleles was 3.78 in E. s. schrenckii and 4.11 in E. s. anomala. The average expected heterozygosity was 0.542 and 0.511 in E. s. schrenckii and E. s. anomala, respectively. We found a lack of genetic structure between two subspecies ($F_{ST}=0.016$) and no genetic discrimination between two subspecies was found. Based on the present findings by microsatellites, two subspecies can be considered as one species, E. schrenckii. However, further investigations on taxonomical status using mitochondrial and nuclear DNA sequences need to be performed and morphological & ecological data should be revised. The genetic markers should benefit future studies of the endangered species of other Elaphe species for the study of genetic diversity and potential conservation management.

• Animal Systematics, Evolution and Diversity
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• 제27권1호
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• pp.1-17
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• 2011

Thais Roding, 1798, commonly known as rock-shell, is among the most frequently found gastropod genera worldwide on intertidal rocky shores including those of Japan, China, Taiwan and Korea. This group contains important species in many marine environmental studies but species-level taxonomy of the group is quite complicated due to the morphological variations in shell characters. This study examined the genetic variations and relationships among three Korean Thais species based on the partial nucleotide sequences of mitochondrial cox1 gene fragments. Phylogenetic trees from different analytic methods (maximum parsimony, neighbor-joining, and maximum likelihood) showed that T. bronni and T. luteostoma are closely related, indicating the most recent common ancestry. The low sequence divergence found between T. luteostoma and T. bronni, ranging from 1.53% to 3.19%, also corroborates this idea. Further molecular survey using different molecular marker is required to fully understand a detailed picture of the origin for their low level of interspecific sequence divergence. Sequence comparisons among conspecific individuals revealed extensive sequence variations within the three species with maximum values of 2.43% in T. clavigera and 1.37% in both T. bronni and T. luteostoma. In addition, there is an unexpectedly high level of mitochondrial genotypic diversity within each of the three Korean Thais species. The high genetic diversity revealed in Korean Thais species is likely to reflect genetic diversity introduced from potential source populations with diverse geographic origins, such as Taiwan, Hong Kong, and a variety of different coastal regions in South China and Japan. Additional sequence analysis with comprehensive taxon sampling from unstudied potential source populations will be also needed to address the origin and key factors for the high level of genetic diversity discovered within the three Korean Thais species studied.

• Journal of Microbiology and Biotechnology
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• 제14권1호
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• pp.182-187
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• 2004

Strain NR $15-1^T$ isolated from traditional Korean Nuruk is described as a new species and named as Aspergillus coreanus NR $15-1^T$ sp. novo Strain NR $15-1^T$ grew rapidly to form yellow-green colonies whose surfaces were velvety on Czapek solution agar. Conidial heads were yellow to light and elliptical, whereas the conidiophore was colorless and typically long. In addition, vesicles were from flask-shaped to globose, and sterigmata are uniseriate. Conidia were spherical and deep yellow-green, and their surfaces were lightly roughened. The G＋C content of strain NR $15-1^T$ was 51 mol% and strain NR $15-1^T$contained a dihydrogenated ubiquinone with Q9 (94.9%) as a major quinone. The nucleotide sequences of strain NR $15-1^T$ in the two Internal Transcribed Spacers (ITS 1 and 2) and 5.8S rDNA showed highest similarity when compared with that of A. tubingensis and A. phoenicis NRRL $365^T$. However, based on morphological and chemotaxonomic characteristics, this strain was different from A. tubingensis and A. phoenicis NRRL $365^T$. On the basis of the data presented, it is proposed that strain NR $15-1^T$ should be placed in the genus Aspergillus as a new species, Aspergillus coreanus sp. novo Therefore, the type strain of the new species is strain NR $15-1^T$ (=KCTC 18075P^T,=KCCM 80006^T$.

• The Plant Pathology Journal
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• 제34권4호
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• pp.269-285
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• 2018

Bacterial leaf blight is a major disease of eucalypt, especially under nursery conditions. Different bacterial species have been associated with the disease in several countries, and despite its importance worldwide, it is not clear to date whether similar disease symptoms are caused by the same or by different etiological agents. In this study, 43 bacterial strains were isolated from blighted eucalypt leaves collected in different geographic areas of Brazil and inoculated onto a susceptible eucalypt clone. Polyphasic taxonomy, including morphological, physiological, biochemical, molecular, and pathogenicity tests showed that only certain strains of Xanthomonas axonopodis caused symptoms of the disease. Strains varied in their aggressiveness, but no correlation with geographic origin was observed. MLSA-based phylogenetic analysis using concatenated dnaK, fyuA, gyrB and rpoD gene sequences allocated the strains in a well-defined clade, corresponding to Rademarker's group RG 9.6. Inoculation of nineteen plant species belonging to seven botanical families with representative strain LPF 602 showed it to be pathogenic only on Eucalyptus spp, and Corymbia spp. Based on distinct biochemical and pathogenic characteristics that differentiate the eucalypt strains from other pathovars of the X. axonopodis species, here we propose their allocation into the new pathovar X. axonopodis pv. eucalyptorum pv. nov.