• Korean Journal of Microbiology
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• v.51 no.4
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• pp.347-354
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• 2015

Soybean is well known to be originated from Korea and far-east Asian countries, and studies of many root nodule bacteria associated with soybean have mainly-focused on nitrogen fixation, but much less study was carried out on bacterial community in the rhizosphere of soybean. In this study, we analyzed the bacterial community in rhizosphere of Korean soybean, Daepungkong using the pyrosequencing method based on the 16S rRNA gene to characterize the change of the rhizosphere community structure according to the growth stages of soybeans and to elucidate bacterial core community in rhizosphere of soybean. Our results revealed that bacterial community of rhizosphere soil differed from that of bulk soil and was composed of a total of 21 bacterial phyla. The predominant phylum in the rhizosphere of soybean was Proteobacteria (36.6-42.5%) and followed by Acidobacteria (8.6-9.4%), Bacteroidetes (6.1-10.9%), Actinobacteria (6.4-9.8%), and Firmicutes (5.7-6.3%). The bacterial core community in soybean rhizosphere was mainly composed of the operational taxonomic units (OTUs) belonging to the phylum Proteobacteria throughout all growth stages. The OTU00006 belonged to the genus Bradyrhizobium had the highest abundance and Steroidobacter, Streptomyces, Devosia were followed. These results show that bacterial core community in soybean rhizosphere was mainly composed of OTUs associated with plant growth promotion and nutrient cycles.

• The Korean Journal of Mycology
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• v.40 no.2
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• pp.73-77
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• 2012

Nomenclatural code for fungi was dramatically modified in the 18th International Botanical Congress (IBC) held in Melbourne, Australia in July 2011. Its name was changed into International Code of Nomenclature for Algae, Fungi and Plants (ICN), which was formerly called as International Code of Botanical Nomenclature (ICBN) of the Vienna Code of 2005. The most important change for fungi is abandoning dual nomenclature and introducing one fungus/one name system (2013. 1). Since more than 10,000 species of fungal names should be renamed based on this new classification system (one fungus/one name system), it is challenging to both mycologists and taxonomic users such as plant pathologists and food scientists. Here, we introduced background, progress and future plan for its transition into one fungus/one name system. The new code is allowing electronic-only publication of names of new taxa (2102. 1) and the requirement for a Latin validating diagnosis was changed to allow either English or Latin for the publication of a new name (2011. 1). Furthermore, pre-publication deposit of key nomenclatural information in a recognized repository is mandatory in ICN (2013. 1). The aims of this manuscript are to introduce new code of fungal nomenclature and recent trends in one fungus/one name system to Korean mycological society.

• The Korean Journal of Mycology
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• v.45 no.1
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• pp.43-53
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• 2017

In this study, we analyzed the densities and taxonomic characteristics of various microorganisms that play important roles in Agaricus bisporus culture medium composting, and examined changes in the levels of decomposition-related enzymes secreted by these microorganisms. Various microorganisms such as thermophilic bacteria, actinomycetes, fluorescent Pseudomonas spp., and filamentous bacteria are closely associated with culture medium composts of Agaricus bisporus. The population densities of microorganisms change, and harmful bacteria disappear during thermophilic composting. Psychrobacter sp., Pseudomonas sp., Bacillus sp., and Pseudoxanthomonas sp. accounted for the highest proportion of bacteria in the culture media during outdoor composting, whereas Bacillus sp. and Psychrobacillus sp. were dominant after pasteurization. Cellulose and hemicellulose enzymes of the microorganisms were important at an early stage of rice straw composting and after decomposition of carbon sources, respectively. Microorganisms that secreted these enzymes were present in the second and third turning stage of composting.

• Journal of the Korean Society of Marine Environment & Safety
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• v.24 no.7
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• pp.898-906
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• 2018

To investigate the effect of yellow dust on phytoplankton, a field survey and physiological experiments were carried out in the waters near Taean Peninsula from April 22 to 26, 2006, when yellow dust occurred. Phytoplankton populations during the yellow dust period were in the range of $26{\sim}290{\times}10^3cells{\cdot}L^{-1}$, a somewhat low standing crop. An increase in diatoms (a main taxonomic group), especially benthic diatoms such as Paralia sulcate, a typical species for active mixed sea water areas, was also remarkable. In addition, the Chl-a concentration after yellow dust exceeded the Chl-a concentration change range according to the tide before yellow dust. As the concentration of yellow sand increased in a yellow sand treatment experiment, primary productivity decreased, and the maximum assimilation number showed the same tendency. In the 48h culture experiment, primary productivity of the test group was lower than that of the control group at the early stage (T0) of yellow sand treatment, but after 48 hours (T48), the test group showed higher primary productivity than the control group. In particular, the primary productivity of the test group significantly increased to 321 % after 48 hours. Therefore, strong physical environment accompanied by yellow dust may temporarily inhibit the growth of phytoplankton in the waters adjacent to China in the early stage of yellow dust, but the formation of stable water mass has also been identified as a potential factor promoting the growth of phytoplankton.

• The Korean Journal of Mycology
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• v.25 no.1 s.80
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• pp.46-67
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• 1997

From 1985 to 1993, we collected 20 isolates throughout Kangwon and obtained 6 isolates from other sources. A. mellea formed rhizomorph actively, and some of A. osroyae were poor in the formation of rhizomorph and some without formation of rhizomorph. A. tabescens was active in the growth of aerial mycelium and poor in the development of rhizomorph. In A. gallica, the mycelium development among the isolates were variable greatly, and especially in isolate A8(KNU-250), the mycelial development was similar to that of A. osroyae, but A8(KNU-250) showed the feature of A. gallica to change medium into brown color. In PCR-RFLP analysis of the IGS region in rDNA, the homology between each isolate in the A. mellea and A. ostoyae showed 100% homology. A. tabescens showed $0.919{\sim}0.974$ homology, and A. gallica showed $0.619{\sim}1.000$ homology. A19 and A12 showed 100% homology as the same group, but compared with other subgroups they showed less than 10% homology as $0.051{\sim}0.108$ value. In RAPD analyses, the isolates of A. mellea showed high homology among themselves as $0.983{\sim}1.000$, and A. ostoyae also showed high similarity. The homology between isolates of A. tabescens showed $0.594{\sim}0.953$ value because A. gallica showed $0.280{\sim}0.733$ value, and the variations between isolates were greater than other species. Especially, A19 and A22 were identified as new novel group which were remoted from other groups, and the homology between these two isolates showed 0.921 value, and the genetic similarity between these groups and other 4 groups showed less than 7% as $0.012{\sim}0.069$ value. Of 5 species identified in this study, 4 species were identified as A. mellea, A. ostoyae, A. tabescens, and A. gallica that were already reported ones and 1 species was suggested as a new specie in Korea.

• Journal of the Korean Society of Marine Environment & Safety
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• v.27 no.7
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• pp.924-942
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• 2021

The expansion of the Changjiang Diluted Water (CDW) plume during summer is known to be a major factor influencing phytoplankton diversity, community structure, and the regional marine environment of the northern East China Sea (ECS). The discharge of the CDW plume was very high in the summer of 2020, and cruise surveys and stationary monitoring were conducted to understand the dynamics of changes in environmental characteristics and the impact on phytoplankton diversity and community structure. A cruise survey was conducted from August 16 to 17, 2020, using R/V Eardo, and a stay survey at the Ieodo Ocean Research Station (IORS) from August 15 to 21, 2020, to analyze phytoplankton diversity and community structure. The southwestern part of the survey area exhibited low salinity and high chlorophyll a fluorescence under the influence of the CDW plume, whereas the southeastern part of the survey area presented high salinity and low chlorophyll a fluorescence under the influence of the Tsushima Warm Current (TWC). The total chlorophyll a concentrations of surface water samples from 12 sampling stations indicated that nano-phytoplankton (20-3 ㎛) and micro-phytoplankton (> 20 ㎛) were the dominant groups during the survey period. Only stations strongly influenced by the TWC presented approximately 50% of the biomass contributed by pico-phytoplankton (< 3 ㎛). The size distribution of phytoplankton in the surface water samples is related to nutrient supplies, and areas where high nutrient (nitrate) supplies were provided by the CDW plume displayed higher biomass contribution by micro-phytoplankton groups. A total of 45 genera of nano- and micro-phytoplankton groups were classified using morphological analysis. Among them, the dominant taxa were the diatoms Guinardia flaccida and Nitzschia spp. and the dinoflagellates Gonyaulax monacantha, Noctiluca scintillans, Gymnodinium spirale, Heterocapsa spp., Prorocentrum micans, and Tripos furca. The sampling stations affected by the TWC and low in nitrate concentrations presented high concentrations of photosynthetic pico-eukaryotes (PPE) and photosynthetic pico-prokaryotes (PPP). Most sampling stations had phosphate-limited conditions. Higher Synechococcus concentrations were enumerated for the sampling stations influenced by low-nutrient water of the TWC using flow cytometry. The NGS analysis revealed 29 clades of Synechococcus among PPP, and 11 clades displayed a dominance rate of 1% or more at least once in one sample. Clade II was the dominant group in the surface water, whereas various clades (Clades I, IV, etc.) were found to be the next dominant groups in the SCM layers. The Prochlorococcus group, belonging to the PPP, observed in the warm water region, presented a high-light-adapted ecotype and did not appear in the northern part of the survey region. PPE analysis resulted in 163 operational taxonomic units (OTUs), indicating very high diversity. Among them, 11 major taxa showed dominant OTUs with more than 5% in at least one sample, while Amphidinium testudo was the dominant taxon in the surface water in the low-salinity region affected by the CDW plume, and the chlorophyta was dominant in the SCM layer. In the warm water region affected by the TWC, various groups of haptophytes were dominant. Observations from the IORS also presented similar results to the cruise survey results for biomass, size distribution, and diversity of phytoplankton. The results revealed the various dynamic responses of phytoplankton influenced by the CDW plume. By comparing the results from the IORS and research cruise studies, the study confirmed that the IORS is an important observational station to monitor the dynamic impact of the CDW plume. In future research, it is necessary to establish an effective use of IORS in preparation for changes in the ECS summer environment and ecosystem due to climate change.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.32 no.2
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• pp.68-81
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• 2014

This study was conducted to identify the spacialty, to illuminate the existence and values of Myeongwoldae(明月臺) and Forest Myeongwol, and to suggest the sustainable usage, preservation and management plans with the purpose of ecological and cultural landscaping characteristic and value identification. The result of the study is as follows. Castle Myeongwol and Port Myeongwol shows the status of Hallim-eup Myeongwol District which is the administrative center of western Jeju as well as is the fortress. Building Wolgyejeongsa and School Woohakdang, the head temple of education and culture, located in Myeongwol District represents the spaciality of Myeonwol-ri which was the center of education. Stand Myeongwol is one of the most representative Confucian cultural landscapes in Jeju Island and the field of communion with nature where scholars enjoy poetries, nature, changgi(Korean chess), and go in the Joseon Dynasty period. It was found that the current relics of Myeongwoldae was recovered through the maintenance project conducted by Youth Group Myeongwol composed with Hongjong-si(洪鍾時) as the center during the Japanese colonial era in 1931. It seems that the stonework of Myeongwoldae composed of three levels in the order of square, octagon, and circle based on the heaven-man unity theory of Confucianism and the octagon in the middle is the messenger of Cheonwonjibang(天圓地方), in other words, between the square-shaped earth and the circle-shaped sky. It is assumed that both Grand Bridge Myeongwol and Bridge Myeongwol were constructed as arched bridges in early days. Bridge Myeongwol is the only arched bridge remaining in Jeju Island now, which has the modern cultural heritage value. In Forest Myeongwol, 97 taxa of plants were confirmed and in accordance with 'Taxonomic Group and Class Criteria of Floristic Specific Plants', eight taxa were found; Arachniodes aristata of FD IV and Ilex cornuta, Piper kadsura, Litsea japonica, Melia azedarach, Xylosma congestum, Richosanthes kirilowii var. japonica, Dichondra repens, Viburnum odoratissimum var. awabuki of FD III. Otherwise, 14 taxa of naturalized plants including Apium leptophylihum which is imported to Jeju Island only were confirmed. In Forest Myeongwol, 77 trees including 41 Celtis sinensis, 30 Aphananthe aspera, two Wylosma congestum, a Pinus densiflora, a Camellia japonica, a Melia azedarach, and an Ilex cornuta form a colony. Based on the researched data, the preservation and plans of Myeongwoldae and Forest Myeongwol is suggested as follows. Myeongwoldae, Bridge Myeongwol, and Forest Myeongwol should be managed as one integrated division. Bridge Myeongwol, an arched bridge which is hard to be found in Jeju Island is a high-standard stonework requiring long-term preservation plans. Otherwise, Grand Bridge Myeongwol that is exposed to accident risks because of deterioration and needs safety diagnosis requires measures according to the result of precise safety diagnosis. It is desirable to restore it to a two-sluice arched bridge as its initial shape and to preserve and use it as a representative local landmark with Stand Myeongwol. In addition, considering the topophsis based on the analysis result, the current name of Jeju Special Self-Governing Province Monument No. 19 'Myoengwol Hackberry Colony' should change to 'Myeongwol Hackberry-Muku Tree Colony'. In addition, the serial number system which is composed without distinction of hackberry and muku tree should be improved and the regular monitoring of big and old trees, specific plants, and naturalized species is required.