Mirye Park - Academia.edu (original) (raw)
Papers by Mirye Park
Journal of the Korea Academia Industrial Cooperation Society, Aug 31, 2014
The red seabream iridovirus (RSIV), which belongs to the iridoviridae, causes infectious fish dis... more The red seabream iridovirus (RSIV), which belongs to the iridoviridae, causes infectious fish diseases in many Asian countries, leading to considerable economic losses to the aquaculture industry. Using the yeast surface display (YSD) technique, a new experimental system was recently developed for the detection and identification of a variety of marine viruses. In this study, a coat protein gene of RSIV was synthesized based on the nucleotide sequence database and subcloned into the yeast expression vector, pCTCON2. The expression of viral coat proteins in the yeast strain, EBY100, was detected by flow cytometry and Western blot analysis. Finally, they were isolated from the yeast surface through a treatment with β-mercaptoethanol. The data suggests that the YSD system can be a useful method for acquiring coating proteins of marine viruses.
Journal of Marine Science and Engineering, May 29, 2021
This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY
Journal of Life Sciences, 2020
Heterosigma akashiwo is a globally distributed raphidophyte that forms blooms and causes signific... more Heterosigma akashiwo is a globally distributed raphidophyte that forms blooms and causes significant losses to the aquaculture industry in many coastal countries. The development of a fast and sensitive detection method is therefore required to facilitate the appropriate warning of harmful algal blooms. In this study, a nuclease protection integrated with sandwich hybridization (NPA-SH) assay was developed to both qualitatively and quantitatively detect H. akashiwo. The NPA, capture and signal probes were designed by nucleotide sequencing of H. akashiwo. The applicability of NPA-SH was evaluated using cultured H. akashiwo cells and field samples collected at Goseong Bay, Korea. The results show that this method has good applicability and effectiveness in analyzing cultured cells and field samples. A linear regression equation for the quantitative analysis of H. akashiwo was obtained, and the lower detection limit of the assay was 1×10 4 cells/ml. There was no statistically significant difference in the results of H. akashiwo quantitation using NPA-SH compared to those obtained using a microscope. These results indicate that NPA-SH can be a good alternative to the traditional microscopic method used to monitor H. akashiwo.
African Journal of Microbiology Research, Feb 11, 2015
Red seabream iridovirus (RSIV), a member of the Iridoviridae family, is the causative pathogen of... more Red seabream iridovirus (RSIV), a member of the Iridoviridae family, is the causative pathogen of some of the most explosive epidemics of emerging viral diseases in many Asian countries, leading to huge economic losses in aquaculture. Rapid molecular detection for surveillance or diagnosis has been a critical component in reducing the prevalence of RSIV infection. In the present study, a novel and highly specific loop-mediated isothermal amplification (LAMP) assay for the sensitive and rapid detection of RSIV infection in fishes was developed. Using a set of synthesized primers matching a specific region of the RSIV genome (GenBank accession no.: AB666336.1), the efficiency and specificity of the LAMP assay were optimized in terms of the reaction temperature and DNA polymerase concentration, as they are the main determinants of the sensitivity and specificity of the LAMP assay. In particular, we demonstrated that our assay could be applied to efficiently detect RSIV infection in red sea bream. Our results provide a simple and convenient method for the detection of viral infection in aquatic organisms.
Journal of the Korea Academia Industrial Cooperation Society, Sep 30, 2014
Mangrove plants serve as a sink of heavy metals and contain phenolic compounds at a high level. T... more Mangrove plants serve as a sink of heavy metals and contain phenolic compounds at a high level. Therefore, with mangrove plants, recent studies to develop phytoremediation and natural antioxidants have been conducted in the commercial and academic fields. In the present study, six mangroves in Weno Island of Micronesia were investigated for their phylogenetic relationship and antioxidant activities. First, to determine the phylogenetic relationship among them, rbcL (large subunit of ribulose-bisphosphate carboxylase), one of the chloroplast genes, was used as a molecular marker. According to the data, Xylocarpus, Sonneratia and Rhizophora showed close similarity but not Excoecaria. The levels of phenolic compounds in the bark were abundant in R. apiculata and X. granatum, accounting for 1.10 mM/mg, while R. stylosa and S. alba contained the low amounts, representing 0.73 mM/mg and 0.72 mM/mg, respectively (p<0.05). In addition, bark extracts from R. apiculata, X. granatum, X. moluccensis, and E. agallocha had high antioxidant activities through the DPPH radical scavenging activity and ABTS analysis, whereas S. alba showed the lowest activities. These results suggest that the bark of R. apiculata can be used as a good source for the development of natural antioxidants.
Ocean Science Journal, Sep 1, 2014
ABSTRACT Understanding the patterns of microbial diversity and their composition in seawater is n... more ABSTRACT Understanding the patterns of microbial diversity and their composition in seawater is necessary to assess the impacts of microbes on marine ecosystem. Although the potential roles of microbes in the ocean have been studied, their diversity and relationship with environmental factors remain unclear. In this study, we adopted a 16S rRNA gene tag-pyrosequencing technique to investigate the bacterial communities associated with two different water masses from Tongyoung in the South Sea of Korea. Our results revealed highly diverse bacterial communities up to 900 Operational Taxonomic Units (OTUs) estimated from each seawater which was collected in the month of March and May, when the environmental conditions including temperature differed significantly: 7.2°C and 17.6°C in March and May, respectively. Altogether, 13 bacterial phyla were recovered from the seawater, of which Proteobacteria was the most dominant group. In addition, the value of the Shannon index, which measures the evenness of the distribution of individuals among OTUs, in May is higher than that in March, indicating that it displays a wider diversity of bacteria. Interestingly, the proportion of pathogenic bacteria was significantly increased in the month of May compared to March, suggesting that pathogenic bacteria were increasingly emerging in May. In particular, Pseudoalteromonas and Vibrio spp. were determined as major pathogenic bacteria from both water masses, of which Vibrio spp. were dominant.
Ocean Science Journal, Dec 1, 2016
Reef-building corals form close associations with organisms from all three domains of life and th... more Reef-building corals form close associations with organisms from all three domains of life and therefore have many potential viral hosts. Yet, knowledge of viral communities associated with corals is barely explored. This complexity presents a number of challenges in terms of the metagenomic assessments of coral viral communities, and requires specialised methods for purification and amplification of viral nucleic acids, as well as virome annotation. In this mini-review, we conduct a meta-analysis of the limited number of existing coral virome studies, as well as available coral transcriptome and metagenome data, to identify trends and potential complications inherent in different methods. The analysis shows that the method used for viral nucleic acid isolation drastically affects the observed viral assemblage and interpretation of the results. Further, the small number of viral reference genomes available, coupled with short sequence read lengths might cause errors in virus identification. Despite these limitations and potential biases, the data show that viral communities associated with corals are diverse, with double-and single-stranded DNA and RNA viruses. The identified viruses are dominated by dsDNA-tailed bacteriophages, but there are also viruses that infect eukaryote hosts, likely the endosymbiotic dinoflagellates, Symbiodinium spp., host coral, and other eukaryotes in close association.
Environmental Toxicology, 2017
African Journal of Microbiology Research, 2015
Red seabream iridovirus (RSIV), a member of the Iridoviridae family, is the causative pathogen of... more Red seabream iridovirus (RSIV), a member of the Iridoviridae family, is the causative pathogen of some of the most explosive epidemics of emerging viral diseases in many Asian countries, leading to huge economic losses in aquaculture. Rapid molecular detection for surveillance or diagnosis has been a critical component in reducing the prevalence of RSIV infection. In the present study, a novel and highly specific loop-mediated isothermal amplification (LAMP) assay for the sensitive and rapid detection of RSIV infection in fishes was developed. Using a set of synthesized primers matching a specific region of the RSIV genome (GenBank accession no.: AB666336.1), the efficiency and specificity of the LAMP assay were optimized in terms of the reaction temperature and DNA polymerase concentration, as they are the main determinants of the sensitivity and specificity of the LAMP assay. In particular, we demonstrated that our assay could be applied to efficiently detect RSIV infection in red sea bream. Our results provide a simple and convenient method for the detection of viral infection in aquatic organisms.
Applied Microscopy, Jan 20, 2023
The Gonggeom-ji reservoir is an agricultural one built for rice farming during the Proto-Three Ki... more The Gonggeom-ji reservoir is an agricultural one built for rice farming during the Proto-Three Kingdoms period and was designated as Gyeongsangbuk-do monument No. 121 because of its high historical value. The Nakdonggang National Institute of Biological Resources has been conducting paleontological and paleoenvironmental studies on major wetlands from Korea since 2016, as well as diatom, geological, and depth distribution analyses on the sedimentary soil of Gonggeom-ji. This study summarized the description and ecological characteristics of six newly recorded diatoms (Gomphonema lacusrankala, Pinnularia diandae, P. gibba var. hyaline, P. lacunarum, Sellaphora labda var. nipponica, Stauroneis angustilancea) found in samples collected through drilling in Gonggeom-ji in 2019.
Journal of Marine Science and Engineering, 2021
Lagoons are natural bodies of water that are isolated from the sea due to the development of a sa... more Lagoons are natural bodies of water that are isolated from the sea due to the development of a sand bar or spit. Each lagoon has distinct ecological characteristics, and these sites also serve as popular tourist attractions because they are common habitats for migratory birds and are characterized by beautiful natural scenery. Lagoons also have distinct ecological characteristics from those of their associated estuaries, and there are active research efforts to classify, qualify, and quantify the high biodiversity of lagoons. The lagoons in Korea are primarily distributed in the East Sea, and are represented by Hwajinpo, Yeongrangho, and Gyeongpoho. Here, we report the discovery of 11 unrecorded diatom species (Diploneis didyma, Mastogloia elliptica, Cosmioneis citriformis, Haslea crucigera, Pinnularia bertrandii, Pinnularia nodosa var. percapitata, Gyrosigma sinense, Gomphonema guaraniarum, Gomphonema italicum, Navicula freesei, Trybionella littoralis var. tergestina) among samples...
Cryobiology, 2021
Algae, which may be unicellular or multicellular, can carry out photosynthesis just like plants a... more Algae, which may be unicellular or multicellular, can carry out photosynthesis just like plants as they effectively utilize light energy. They contain various physiologically active substances and are, therefore, widely used commercially to produce healthy food and feed additives, cosmetics, and energy supplements. For useful applications, the cryopreservation technique has been used in various fields. Recently, to develop suitable cryopreservation methods for algal applications, various studies have been performed. However, adequate investigations have not been conducted to understand the mechanism underlying algal cryopreservation at the molecular level. Therefore, this study examined the profile alteration of the proteome using cryopreservation with various cryoprotectants (CPAs). Trichormus variabilis was cultured and then cryopreserved with 10% dimethyl sulfoxide, methanol, and glycerol, after which, proteome profiling was done. Finally, signaling pathway search was performed, and a new signaling pathway was established based on differentially expressed proteins. As a result, the expression levels of 17 proteins were observed. Additionally, it was confirmed that the differentially expressed proteins were related to 16 signaling pathways and that they were capable of interacting with each other. The findings suggest that the differentially expressed proteins may be applied as biomarkers for algal cryopreservation and to understand the mechanism underlying T. variabilis cryopreservation. Moreover, it is anticipated that the results from this study would be useful in selecting suitable CPAs and in upgrading the cryopreservation techniques.
Journal of Life Science, 2020
Heterosigma akashiwo is a globally distributed raphidophyte that forms blooms and causes signific... more Heterosigma akashiwo is a globally distributed raphidophyte that forms blooms and causes significant losses to the aquaculture industry in many coastal countries. The development of a fast and sensitive detection method is therefore required to facilitate the appropriate warning of harmful algal blooms. In this study, a nuclease protection integrated with sandwich hybridization (NPA-SH) assay was developed to both qualitatively and quantitatively detect H. akashiwo. The NPA, capture and signal probes were designed by nucleotide sequencing of H. akashiwo. The applicability of NPA-SH was evaluated using cultured H. akashiwo cells and field samples collected at Goseong Bay, Korea. The results show that this method has good applicability and effectiveness in analyzing cultured cells and field samples. A linear regression equation for the quantitative analysis of H. akashiwo was obtained, and the lower detection limit of the assay was 1×10 4 cells/ml. There was no statistically significant difference in the results of H. akashiwo quantitation using NPA-SH compared to those obtained using a microscope. These results indicate that NPA-SH can be a good alternative to the traditional microscopic method used to monitor H. akashiwo.
Cryobiology, 2021
This is a PDF file of an article that has undergone enhancements after acceptance, such as the ad... more This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
Diatom Research, 2020
Late Holocene diatoms were identified from four sediment cores from the Gonggeomji Wetland in Kor... more Late Holocene diatoms were identified from four sediment cores from the Gonggeomji Wetland in Korea. In total, 52 diatom species belonging to three classes, 21 families, and 29 genera were investigated. Of these, 14 species were new records for Korea: Caloneis wardii, Cocconeis klamathensis, Encyonema vulgare, Eunotia myrmica, Fallacia californica, Gomphonema asiaticum, Gomphonema insigniturris, Gomphonema neoapiculatum, Gomphonema tumens, Pinnularia fusana, Pinnularia parvulissima, Punctastriata lancettula, Sellaphora capitata, and Staurosira dimorpha. Eleven taxa could not be identified to the species level. All identified diatoms are illustrated by high-quality scanning electron microphotographs, reference taxonomic data, dimensions of the observed cells, and information on ecology and distribution are included.
Korean Journal of Ecology and Environment, 2020
Aquatic Ecosystem Health & Management, 2018
Microalgae are important primary producers in the marine environment, and are also important sour... more Microalgae are important primary producers in the marine environment, and are also important sources of health foods and medical products. Rapidly growing microalgae have potential use for the production of commercial products, but can also cause harmful microalgal blooms in natural ecosystems. There are many available techniques for the identification of microalgae in natural ecosystems. We used the mitochondrial cytochrome c oxidase subunit I gene as DNA barcode to identify 14 species of microalgae from the South Sea of Korea and to discriminate among similar biogeographic subgroups within species. In addition, we designed species-specific primers targeting the cytochrome c oxidase subunit I gene to evaluate monthly changes of microalgae throughout the year. Chaetoceros brevis, Asterionellopsis glacialis and Stephanopyxis turris were present during all seasons, whereas Skeletonema japonicum, Nitzschia improvisa, Ditylum brightwellii and Chaetoceros diadema were only detected during winter and spring. Our results indicate that species-specific polymerase chain reaction of the cytochrome c oxidase subunit I gene can be used to monitor the seasonal dynamics of microalgae in the South Sea of Korea. This polymerase chain reaction detection method successfully identified the 14 most common species of microalgae with the same polymerase chain reaction condition near Tongyeong, in the South Sea of Korea.
Microbiology and Biotechnology Letters, 2020
Cyanobacteria are microorganisms which have important roles in the nitrogen cycle due to their ab... more Cyanobacteria are microorganisms which have important roles in the nitrogen cycle due to their ability to fix nitrogen in water and soil ecosystems. They also produce valuable materials that may be used in various industries. However, some species of cyanobacteria may limit the use of water resources by causing harmful algal blooms in water ecosystems. Many culture collection depositories provide cyanobacterial strains for research, but their systematic preservation is not well-developed in Korea. In this study, we developed a method for the cryopreservation of the cyanobacteria Trichormus variabilis (syn. Anabaena variabilis), using alginate microcapsules. Two approaches were used for the experiments and their outputs were compared. One of the methods involved the cryopreservation of cells using only a cryoprotectant and the other used the cryoprotectant within microcapsules. After cryopreservation for 35 days, cells preserved with both methods were successfully regenerated from the initial 1.0 × 10 5 cells/ml to a final concentration of 6.7 × 10 6 cells/ml and 1.1 × 10 7 cells/ml. Irregular T. variabilis shapes were found after 14 days of regeneration. T. variabilis internal structures were observed by transmission electron microscopy (TEM), revealing that lipid droplets were reduced after cryopreservation. The expression of the mreB gene, known to be related to cell morphology, was downregulated (54.7%) after cryopreservation. Cryopreservation using cryoprotectant alone or with microcapsules is expected to be applicable to other filamentous cyanobacteria in the future.
Journal of the Korea Academia Industrial Cooperation Society, Aug 31, 2014
The red seabream iridovirus (RSIV), which belongs to the iridoviridae, causes infectious fish dis... more The red seabream iridovirus (RSIV), which belongs to the iridoviridae, causes infectious fish diseases in many Asian countries, leading to considerable economic losses to the aquaculture industry. Using the yeast surface display (YSD) technique, a new experimental system was recently developed for the detection and identification of a variety of marine viruses. In this study, a coat protein gene of RSIV was synthesized based on the nucleotide sequence database and subcloned into the yeast expression vector, pCTCON2. The expression of viral coat proteins in the yeast strain, EBY100, was detected by flow cytometry and Western blot analysis. Finally, they were isolated from the yeast surface through a treatment with β-mercaptoethanol. The data suggests that the YSD system can be a useful method for acquiring coating proteins of marine viruses.
Journal of Marine Science and Engineering, May 29, 2021
This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY
Journal of Life Sciences, 2020
Heterosigma akashiwo is a globally distributed raphidophyte that forms blooms and causes signific... more Heterosigma akashiwo is a globally distributed raphidophyte that forms blooms and causes significant losses to the aquaculture industry in many coastal countries. The development of a fast and sensitive detection method is therefore required to facilitate the appropriate warning of harmful algal blooms. In this study, a nuclease protection integrated with sandwich hybridization (NPA-SH) assay was developed to both qualitatively and quantitatively detect H. akashiwo. The NPA, capture and signal probes were designed by nucleotide sequencing of H. akashiwo. The applicability of NPA-SH was evaluated using cultured H. akashiwo cells and field samples collected at Goseong Bay, Korea. The results show that this method has good applicability and effectiveness in analyzing cultured cells and field samples. A linear regression equation for the quantitative analysis of H. akashiwo was obtained, and the lower detection limit of the assay was 1×10 4 cells/ml. There was no statistically significant difference in the results of H. akashiwo quantitation using NPA-SH compared to those obtained using a microscope. These results indicate that NPA-SH can be a good alternative to the traditional microscopic method used to monitor H. akashiwo.
African Journal of Microbiology Research, Feb 11, 2015
Red seabream iridovirus (RSIV), a member of the Iridoviridae family, is the causative pathogen of... more Red seabream iridovirus (RSIV), a member of the Iridoviridae family, is the causative pathogen of some of the most explosive epidemics of emerging viral diseases in many Asian countries, leading to huge economic losses in aquaculture. Rapid molecular detection for surveillance or diagnosis has been a critical component in reducing the prevalence of RSIV infection. In the present study, a novel and highly specific loop-mediated isothermal amplification (LAMP) assay for the sensitive and rapid detection of RSIV infection in fishes was developed. Using a set of synthesized primers matching a specific region of the RSIV genome (GenBank accession no.: AB666336.1), the efficiency and specificity of the LAMP assay were optimized in terms of the reaction temperature and DNA polymerase concentration, as they are the main determinants of the sensitivity and specificity of the LAMP assay. In particular, we demonstrated that our assay could be applied to efficiently detect RSIV infection in red sea bream. Our results provide a simple and convenient method for the detection of viral infection in aquatic organisms.
Journal of the Korea Academia Industrial Cooperation Society, Sep 30, 2014
Mangrove plants serve as a sink of heavy metals and contain phenolic compounds at a high level. T... more Mangrove plants serve as a sink of heavy metals and contain phenolic compounds at a high level. Therefore, with mangrove plants, recent studies to develop phytoremediation and natural antioxidants have been conducted in the commercial and academic fields. In the present study, six mangroves in Weno Island of Micronesia were investigated for their phylogenetic relationship and antioxidant activities. First, to determine the phylogenetic relationship among them, rbcL (large subunit of ribulose-bisphosphate carboxylase), one of the chloroplast genes, was used as a molecular marker. According to the data, Xylocarpus, Sonneratia and Rhizophora showed close similarity but not Excoecaria. The levels of phenolic compounds in the bark were abundant in R. apiculata and X. granatum, accounting for 1.10 mM/mg, while R. stylosa and S. alba contained the low amounts, representing 0.73 mM/mg and 0.72 mM/mg, respectively (p<0.05). In addition, bark extracts from R. apiculata, X. granatum, X. moluccensis, and E. agallocha had high antioxidant activities through the DPPH radical scavenging activity and ABTS analysis, whereas S. alba showed the lowest activities. These results suggest that the bark of R. apiculata can be used as a good source for the development of natural antioxidants.
Ocean Science Journal, Sep 1, 2014
ABSTRACT Understanding the patterns of microbial diversity and their composition in seawater is n... more ABSTRACT Understanding the patterns of microbial diversity and their composition in seawater is necessary to assess the impacts of microbes on marine ecosystem. Although the potential roles of microbes in the ocean have been studied, their diversity and relationship with environmental factors remain unclear. In this study, we adopted a 16S rRNA gene tag-pyrosequencing technique to investigate the bacterial communities associated with two different water masses from Tongyoung in the South Sea of Korea. Our results revealed highly diverse bacterial communities up to 900 Operational Taxonomic Units (OTUs) estimated from each seawater which was collected in the month of March and May, when the environmental conditions including temperature differed significantly: 7.2°C and 17.6°C in March and May, respectively. Altogether, 13 bacterial phyla were recovered from the seawater, of which Proteobacteria was the most dominant group. In addition, the value of the Shannon index, which measures the evenness of the distribution of individuals among OTUs, in May is higher than that in March, indicating that it displays a wider diversity of bacteria. Interestingly, the proportion of pathogenic bacteria was significantly increased in the month of May compared to March, suggesting that pathogenic bacteria were increasingly emerging in May. In particular, Pseudoalteromonas and Vibrio spp. were determined as major pathogenic bacteria from both water masses, of which Vibrio spp. were dominant.
Ocean Science Journal, Dec 1, 2016
Reef-building corals form close associations with organisms from all three domains of life and th... more Reef-building corals form close associations with organisms from all three domains of life and therefore have many potential viral hosts. Yet, knowledge of viral communities associated with corals is barely explored. This complexity presents a number of challenges in terms of the metagenomic assessments of coral viral communities, and requires specialised methods for purification and amplification of viral nucleic acids, as well as virome annotation. In this mini-review, we conduct a meta-analysis of the limited number of existing coral virome studies, as well as available coral transcriptome and metagenome data, to identify trends and potential complications inherent in different methods. The analysis shows that the method used for viral nucleic acid isolation drastically affects the observed viral assemblage and interpretation of the results. Further, the small number of viral reference genomes available, coupled with short sequence read lengths might cause errors in virus identification. Despite these limitations and potential biases, the data show that viral communities associated with corals are diverse, with double-and single-stranded DNA and RNA viruses. The identified viruses are dominated by dsDNA-tailed bacteriophages, but there are also viruses that infect eukaryote hosts, likely the endosymbiotic dinoflagellates, Symbiodinium spp., host coral, and other eukaryotes in close association.
Environmental Toxicology, 2017
African Journal of Microbiology Research, 2015
Red seabream iridovirus (RSIV), a member of the Iridoviridae family, is the causative pathogen of... more Red seabream iridovirus (RSIV), a member of the Iridoviridae family, is the causative pathogen of some of the most explosive epidemics of emerging viral diseases in many Asian countries, leading to huge economic losses in aquaculture. Rapid molecular detection for surveillance or diagnosis has been a critical component in reducing the prevalence of RSIV infection. In the present study, a novel and highly specific loop-mediated isothermal amplification (LAMP) assay for the sensitive and rapid detection of RSIV infection in fishes was developed. Using a set of synthesized primers matching a specific region of the RSIV genome (GenBank accession no.: AB666336.1), the efficiency and specificity of the LAMP assay were optimized in terms of the reaction temperature and DNA polymerase concentration, as they are the main determinants of the sensitivity and specificity of the LAMP assay. In particular, we demonstrated that our assay could be applied to efficiently detect RSIV infection in red sea bream. Our results provide a simple and convenient method for the detection of viral infection in aquatic organisms.
Applied Microscopy, Jan 20, 2023
The Gonggeom-ji reservoir is an agricultural one built for rice farming during the Proto-Three Ki... more The Gonggeom-ji reservoir is an agricultural one built for rice farming during the Proto-Three Kingdoms period and was designated as Gyeongsangbuk-do monument No. 121 because of its high historical value. The Nakdonggang National Institute of Biological Resources has been conducting paleontological and paleoenvironmental studies on major wetlands from Korea since 2016, as well as diatom, geological, and depth distribution analyses on the sedimentary soil of Gonggeom-ji. This study summarized the description and ecological characteristics of six newly recorded diatoms (Gomphonema lacusrankala, Pinnularia diandae, P. gibba var. hyaline, P. lacunarum, Sellaphora labda var. nipponica, Stauroneis angustilancea) found in samples collected through drilling in Gonggeom-ji in 2019.
Journal of Marine Science and Engineering, 2021
Lagoons are natural bodies of water that are isolated from the sea due to the development of a sa... more Lagoons are natural bodies of water that are isolated from the sea due to the development of a sand bar or spit. Each lagoon has distinct ecological characteristics, and these sites also serve as popular tourist attractions because they are common habitats for migratory birds and are characterized by beautiful natural scenery. Lagoons also have distinct ecological characteristics from those of their associated estuaries, and there are active research efforts to classify, qualify, and quantify the high biodiversity of lagoons. The lagoons in Korea are primarily distributed in the East Sea, and are represented by Hwajinpo, Yeongrangho, and Gyeongpoho. Here, we report the discovery of 11 unrecorded diatom species (Diploneis didyma, Mastogloia elliptica, Cosmioneis citriformis, Haslea crucigera, Pinnularia bertrandii, Pinnularia nodosa var. percapitata, Gyrosigma sinense, Gomphonema guaraniarum, Gomphonema italicum, Navicula freesei, Trybionella littoralis var. tergestina) among samples...
Cryobiology, 2021
Algae, which may be unicellular or multicellular, can carry out photosynthesis just like plants a... more Algae, which may be unicellular or multicellular, can carry out photosynthesis just like plants as they effectively utilize light energy. They contain various physiologically active substances and are, therefore, widely used commercially to produce healthy food and feed additives, cosmetics, and energy supplements. For useful applications, the cryopreservation technique has been used in various fields. Recently, to develop suitable cryopreservation methods for algal applications, various studies have been performed. However, adequate investigations have not been conducted to understand the mechanism underlying algal cryopreservation at the molecular level. Therefore, this study examined the profile alteration of the proteome using cryopreservation with various cryoprotectants (CPAs). Trichormus variabilis was cultured and then cryopreserved with 10% dimethyl sulfoxide, methanol, and glycerol, after which, proteome profiling was done. Finally, signaling pathway search was performed, and a new signaling pathway was established based on differentially expressed proteins. As a result, the expression levels of 17 proteins were observed. Additionally, it was confirmed that the differentially expressed proteins were related to 16 signaling pathways and that they were capable of interacting with each other. The findings suggest that the differentially expressed proteins may be applied as biomarkers for algal cryopreservation and to understand the mechanism underlying T. variabilis cryopreservation. Moreover, it is anticipated that the results from this study would be useful in selecting suitable CPAs and in upgrading the cryopreservation techniques.
Journal of Life Science, 2020
Heterosigma akashiwo is a globally distributed raphidophyte that forms blooms and causes signific... more Heterosigma akashiwo is a globally distributed raphidophyte that forms blooms and causes significant losses to the aquaculture industry in many coastal countries. The development of a fast and sensitive detection method is therefore required to facilitate the appropriate warning of harmful algal blooms. In this study, a nuclease protection integrated with sandwich hybridization (NPA-SH) assay was developed to both qualitatively and quantitatively detect H. akashiwo. The NPA, capture and signal probes were designed by nucleotide sequencing of H. akashiwo. The applicability of NPA-SH was evaluated using cultured H. akashiwo cells and field samples collected at Goseong Bay, Korea. The results show that this method has good applicability and effectiveness in analyzing cultured cells and field samples. A linear regression equation for the quantitative analysis of H. akashiwo was obtained, and the lower detection limit of the assay was 1×10 4 cells/ml. There was no statistically significant difference in the results of H. akashiwo quantitation using NPA-SH compared to those obtained using a microscope. These results indicate that NPA-SH can be a good alternative to the traditional microscopic method used to monitor H. akashiwo.
Cryobiology, 2021
This is a PDF file of an article that has undergone enhancements after acceptance, such as the ad... more This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
Diatom Research, 2020
Late Holocene diatoms were identified from four sediment cores from the Gonggeomji Wetland in Kor... more Late Holocene diatoms were identified from four sediment cores from the Gonggeomji Wetland in Korea. In total, 52 diatom species belonging to three classes, 21 families, and 29 genera were investigated. Of these, 14 species were new records for Korea: Caloneis wardii, Cocconeis klamathensis, Encyonema vulgare, Eunotia myrmica, Fallacia californica, Gomphonema asiaticum, Gomphonema insigniturris, Gomphonema neoapiculatum, Gomphonema tumens, Pinnularia fusana, Pinnularia parvulissima, Punctastriata lancettula, Sellaphora capitata, and Staurosira dimorpha. Eleven taxa could not be identified to the species level. All identified diatoms are illustrated by high-quality scanning electron microphotographs, reference taxonomic data, dimensions of the observed cells, and information on ecology and distribution are included.
Korean Journal of Ecology and Environment, 2020
Aquatic Ecosystem Health & Management, 2018
Microalgae are important primary producers in the marine environment, and are also important sour... more Microalgae are important primary producers in the marine environment, and are also important sources of health foods and medical products. Rapidly growing microalgae have potential use for the production of commercial products, but can also cause harmful microalgal blooms in natural ecosystems. There are many available techniques for the identification of microalgae in natural ecosystems. We used the mitochondrial cytochrome c oxidase subunit I gene as DNA barcode to identify 14 species of microalgae from the South Sea of Korea and to discriminate among similar biogeographic subgroups within species. In addition, we designed species-specific primers targeting the cytochrome c oxidase subunit I gene to evaluate monthly changes of microalgae throughout the year. Chaetoceros brevis, Asterionellopsis glacialis and Stephanopyxis turris were present during all seasons, whereas Skeletonema japonicum, Nitzschia improvisa, Ditylum brightwellii and Chaetoceros diadema were only detected during winter and spring. Our results indicate that species-specific polymerase chain reaction of the cytochrome c oxidase subunit I gene can be used to monitor the seasonal dynamics of microalgae in the South Sea of Korea. This polymerase chain reaction detection method successfully identified the 14 most common species of microalgae with the same polymerase chain reaction condition near Tongyeong, in the South Sea of Korea.
Microbiology and Biotechnology Letters, 2020
Cyanobacteria are microorganisms which have important roles in the nitrogen cycle due to their ab... more Cyanobacteria are microorganisms which have important roles in the nitrogen cycle due to their ability to fix nitrogen in water and soil ecosystems. They also produce valuable materials that may be used in various industries. However, some species of cyanobacteria may limit the use of water resources by causing harmful algal blooms in water ecosystems. Many culture collection depositories provide cyanobacterial strains for research, but their systematic preservation is not well-developed in Korea. In this study, we developed a method for the cryopreservation of the cyanobacteria Trichormus variabilis (syn. Anabaena variabilis), using alginate microcapsules. Two approaches were used for the experiments and their outputs were compared. One of the methods involved the cryopreservation of cells using only a cryoprotectant and the other used the cryoprotectant within microcapsules. After cryopreservation for 35 days, cells preserved with both methods were successfully regenerated from the initial 1.0 × 10 5 cells/ml to a final concentration of 6.7 × 10 6 cells/ml and 1.1 × 10 7 cells/ml. Irregular T. variabilis shapes were found after 14 days of regeneration. T. variabilis internal structures were observed by transmission electron microscopy (TEM), revealing that lipid droplets were reduced after cryopreservation. The expression of the mreB gene, known to be related to cell morphology, was downregulated (54.7%) after cryopreservation. Cryopreservation using cryoprotectant alone or with microcapsules is expected to be applicable to other filamentous cyanobacteria in the future.