• Journal of Korean Society of Forest Science
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• v.64 no.1
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• pp.52-63
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• 1984

This study was intended to identify 17 taxa. (5 varieties and 12 species) of the genus Acer in Korea on the basis of the shapes of stomata, the type of trichome on the different part of leaves, the shapes, arrangement and number of stele in cross section of petiole. The results obtained were summarized as follows; 11 The shape of guard cells of stomata in the genus Acer was anomcytical, and the size of the cells ranged from 10.25 to $21.00{\mu}$ in length and from 7.57 to $11.83{\mu}$ in width. 2) Eleven types of trichome on the leaf in the genus Acer were found; pilose, sericeous, velutinous, woolly, glabrate, puberulent, bladder hair, hispid, hirsute and uncinate. This characteristics also established a good criterion for identification of species. 3) The stele of petiole in the genus Acer was characterized by eustele and atactostele with polybranch, and the six groups of the shape of numerical change of stele; B>M=T, BM

• The Korean Journal of Malacology
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• v.32 no.2
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• pp.127-131
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• 2016

The natives of the genus Corbicula have shown worldwide dispersion in recent times, which has caused great ecological and economic impacts on the introduced ecosystems. The species reported from the genus have been consumed as food and explored for medicine with pharmacological activity. Consequently, the demand of Corbicula sp. in the South Korean domestic market has increased and so also it's associated import to the country. However, due to the absence of identification keys of imported Corbicula, the market is facing confronting situations. We hypothesized that the mitochondrial Cytochrome Oxidase I gene (CO-I) based molecular profiling could be a necessary technique for identification of Corbicula sp. in the South Korea domestic market. The genetic analysis identified both Corbicula japonica and Corbicula fluminea from the market foods. C. japonica and C. fluminea are inhabitants in Korea, but C. fluminea production has decreased in Seomjingang river basin. Therefore, C. fluminea identified from this study, is expected to be imported from China and would have a mixed sales in Seomjingang river side basin.

• Journal of Microbiology and Biotechnology
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• v.27 no.9
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• pp.1593-1601
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• 2017

Vibrio species are generally recognized as pathogens predominant in seafood along coastal areas. The food industry has sought to develop efficient microbial detection methods. Owing to the limits of conventional methods, this study aimed to establish a rapid identification method for Vibrio isolated from Korea, based on matrix-assisted laser-desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). Four different preparation procedures were compared to determine the appropriate means to pretreat Vibrio species, using 17 isolates and five reference strains. Extended direct transfer and full formic acid extraction methods using bacterial colonies on agar plates revealed very low identification rates. Formic acid and trifluoroacetic acid (TFA) extractions using bacterial broth cultures were also performed. All Vibrio isolates and reference strains prepared by TFA extraction were successfully identified to the species level (17/22, 77.3%) and to the genus level (5/22, 22.7%). Thus, TFA extraction was considered the most appropriate method to pretreat Vibrio species for MALDI-TOF MS. The remaining 33 isolates and two reference strains were prepared by TFA extraction and analyzed by MALDI-TOF MS. Overall, 50 isolates were identified to the species level (40/50, 80%) and to the genus level (10/50, 20%). All isolates were identified as 43 V. alginolyticus, six V. parahaemolyticus, and one V. vulnificus species. V. alginolyticus and V. parahaemolyticus were isolated from fish offal (87.5% and 12.5%, respectively), seawater (91.3%, 8.7%), and shellfish (62.5%, 37.5%), whereas V. alginolyticus and V. vulnificus were isolated from sediment (90.9% and 9.1%, respectively). This study established a reliable system of MALDI-TOF MS preparation and analysis for Vibrio identification.

• Journal of Korean Society of Forest Science
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• v.110 no.2
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• pp.155-164
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• 2021

Many studies have been conducted on developing automatic plant identification algorithms using machine learning to various plant features, such as leaves and flowers. Unlike other plant characteristics, barks show only little change regardless of the season and are maintained for a long period. Nevertheless, barks show a complex shape with a large variation depending on the environment, and there are insufficient materials that can be utilized to train algorithms. Here, in addition to the previously published bark image dataset, BarkNet v.1.0, images of barks were collected, and a dataset consisting of 53 tree species that can be easily observed in Korea was presented. A convolutional neural network (CNN) was trained and tested on the dataset, and the factors that interfere with the model's performance were identified. For CNN architecture, VGG-16 and 19 were utilized. As a result, VGG-16 achieved 90.41% and VGG-19 achieved 92.62% accuracy. When tested on new tree images that do not exist in the original dataset but belong to the same genus or family, it was confirmed that more than 80% of cases were successfully identified as the same genus or family. Meanwhile, it was found that the model tended to misclassify when there were distracting features in the image, including leaves, mosses, and knots. In these cases, we propose that random cropping and classification by majority votes are valid for improving possible errors in training and inferences.

• Journal of Dairy Science and Biotechnology
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• v.24 no.1
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• pp.19-28
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• 2006

This study was conducted to isolate antilisterial strains of the Bifidobacterium isolates from the infant feces. The bifidobacteria were isolated anaerobically on BL agar and screened for their inhibitory activity on the MRS-cysteine medium against three foodborne pathogens: Listeria monocytogenes, Bacillus cereus, and Staphylococcus aureus. Among the 52 bifidobacterial isolates, 5 strains(A24, Bl, B6, B10, and Bl2) were finally selected based on their stronger antilisterial activity against Listeria monocytogenes than other isolates tested. Morphologically, all the isolates were typically shown Y-and V-shaped under electron microscopic examination. Each isolate was primarily subjected to identification by a polymerase chain reaction(PCR) using a genus-specific primer designed for targeting the 16S rRNA gene sequence, and confirmed the primary identification data using an API-kit(Biomeriuex, France), commercially available product for identification based on biochemical and physiological traits. Of the isolates with antilisterial activity, strain A24 was finally confirmed as the Bifidobacterium longum A24.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.42 no.2
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• pp.146-150
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• 2009

Genetic variation and relationship of two wild (Pampus argenteus and P. echinogaster) and one cultured (P. chinesis) pomfret fish belonging to the genus Pampus were assessed. Specimens were collected from Korea and China and subjected to amplified fragment length polymorphism (AFLP) DNA fingerprinting. Four primer combinations generated a total of 304 DNA fragments ranging from 153 to 251 bands. Polymorphism and genetic diversity of cultured P. chinensis (22.9% and 0.038) were significantly lower than the two wild species of P. argenteus (93.6% and 0.311) and P. echinogaster (94.0% and 0.290). Genetic distance ranged from 0.335 (P. argenteus and P. echinogaster) to 0.646 (P. argenteus and P. chinensis) and showed a congeneric relationship within this genus. Twenty one of specific AFLP markers from four primer combinations bands were produced. These results suggest that AFLP polymorphism may be a useful marker for genetic identification among the three species studies here.

• Journal of Ecology and Environment
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• v.36 no.4
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• pp.449-463
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• 2013

DNA barcoding is becoming a widely applied tool to accurately discriminate red algae. We tested the effectiveness of DNA barcoding for identification and discovery of Champia species in Korea and clarified the phylogenetic relationships using the plastid rbcL gene. As results, we described four species of Champia such as C. inkyua sp. nov., C. recta Noda, C. bifida Okamura, and C. expansa Yendo. A new species, C. inkyua, is characterized by entangled thallus, terete and irregular branches, hooked apices, and longitudinal filaments running throughout the frond periphery only. Longitudinal filaments were composed of a complete cell with two half cells between diaphragms in the cavity. C. recta and C. bifida were reinstated with previously used names of C. parvula and C. compressa, respectively. C. recta is the first recorded species from Korea and is characterized by an erect thallus, terete and irregular branches, and straight apices. C. bifida is characterized by compressed thallus, pinnate or alternate branches, and bifid apices. C. expansa is characterized by flabellate thallus and dichotomous branches. Molecular analyses of COI and rbcL genes revealed sufficient sequence divergence to warrant species recognition in the genus Champia.

• ALGAE
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• v.27 no.4
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• pp.225-234
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• 2012

Zygnema is a conjugating filamentous green algal genus that is distributed in a broad range of freshwater habitats, from sea level to alpine summits. Although more than 150 species have been described worldwide, their taxonomy remains unclear, probably owing to their relatively simple morphology. We investigated the detailed morphology of Korean Zygnema species, combined with analysis of the plastid psbA gene from 22 specimens of the genus and putative relatives, in order to develope a key to their identification and isolation, and to determine their relationships. We recognized two species of Zygnema; Z. insigne and Z. leiospermum, based on morphological characters such as width of the vegetative cell, position of zygospores, dimensions and form of spores, shape of female gametangia, and color of mesospores. The analysis of psbA data was consistent with morphological comparison. The pairwise divergence between two species was 3.7-4.1% (34-38 bp) in psbA sequences. The phylogeny of psbA revealed the monophyly of Z. insigne and Z. leiospermum together with two isolates of Z. circumcarinatum from Germany and Scotland. This is the first report on the psbA gene phylogeny of Zygnema.

• Journal of Microbiology and Biotechnology
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• v.13 no.6
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• pp.846-852
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• 2003

rpoB DNAs (279 bp) from 34 species of 5 actinomycete genera were sequenced and a phylogenetic tree was constructed based on the sequences obtained. The genera were clearly differentiated in the rpoB tree, forming clades specific to their respective genus. In addition, 2 signature amino acid residues specific to Streptomyces were found in a multiple alignment of the deduced amino acid sequences. To empirically confirm that this rpoB gene analysis system could be used to differentiate actinomycete isolates, the proposed system was used to identify 16 actinomycete isolates from Jeju Island. All isolates were successfully differentiated into the genera Streptomyces and Micromonospora. Accordingly, this is the first report that an rpoB sequence analysis has been effectively used to differentiate actinomycete strains at the genus level.

• Korean Journal of Agricultural Science
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• v.16 no.1
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• pp.19-25
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• 1989

Twelve isolates of bacteria obtained from infected onions were classified into genus Erwinia based on diagnostic characteristics. Of twelve isolates studied, five were identified as E. carotovora subsp. carotovora, six as E. rhapontici and one as E. chrysanthemi on the bases of bacteriological properties. Symptoms caused by the genus Erwinia were different to be identified among the species. Therefore, we propose to name the disease of onion caused by E. carotovora subsp. carotovora, E. rhapontici and E. chrysanthemi as "bacterial soft rot of onion".