• Mycobiology
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• v.43 no.4
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• pp.475-480
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• 2015

A fungal internal transcribed spacer region was used to identify the mycorrhizae of Cymbidium kanran. The family Russulaceae was found to be the most frequently occurring group in both root and soil samples. In phylogenetic analyses, the majority of the Russulaceae clones were clustered with Russula brevipes and R. cyanoxantha. Therefore, C. kanran may form symbiotic relationships with the genus Russula.

• Mycobiology
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• v.45 no.4
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• pp.312-317
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• 2017

Orchidaceous plants have symbiotic relationships with endophytic fungi, including mycorrhizal fungi, which play important roles in the seed germination and growth of the host plants. In this study, endophytic fungal communities isolated from the roots of Cephalanthera longibracteata collected from three different sites in Korea were analyzed, and it was determined whether fungal communities were preferentially correlated with the sites. The fungal isolates were identified by sequence analysis of the internal transcribed spacer regions of rDNA. In total, 30 species of endophytic fungi, including two species of mycorrhizal fungi belonging to the genus Tulasnella, were identified. Leptodontidium orchidicola showed the highest frequency and was isolated from all root samples. Species diversity and richness were not significantly different among sites. However, the community structure of the endophytic fungi significantly differed among sites, suggesting that the site characteristics affected the community composition of the endophytic fungi colonizing the roots of C. longibracteata. Our findings will aid in developing methods involving the use of symbiotic fungi for orchid conservation and restoration in native habitats.

• Journal of Korea Technology Innovation Society
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• v.22 no.2
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• pp.220-241
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• 2019

In order to provide theoretical guidance to research in platform strategy, we build the conceptual framework based on the organizational ecology and analyze symbiotic/competitive relationship between platform entities. Platform owner and service provider (i.e. complementors) make symbiotic relationship, where platform owner provide service provider user-base and platform resources such as marketing tools and platform technology, and service provider provide platform owner services which users utilize. In addition to symbiotic relationships, platform owner has competitive relationship with other platform owners, and service provider builds competitive relationship with other service providers. In these relationships, the strategy of platform owner affects service provider and service provider builds a strategy for their own survival and success. This type of interaction makes competitive dynamics in platform. However, previous platform literature focuses on strategies to enhance network effect from the perspective of platform owner. Thus, there is little attention on interaction among the service providers. Using the framework based on community ecology of organizational ecology, we analyze interaction and strategy between platform owner and service provider in the viewpoint of platform openness strategy and platform pricing strategy. This research contributes to the literature of platform strategy by providing a theoretical framework based on organizational ecology to deeply understand the dynamics of platform.

• The Korean Journal of Malacology
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• v.23 no.1
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• pp.9-16
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• 2007

Data obtained from field observation revealed that the degree of shell bioerosion of the scallop, Patinopecten (Mizuhopecten) yessoensis, by endolithic organisms significantly higher on the muddy sand than on the sand. At the area studied, the polychaete worm, Polydora brevipalpa (=Polydora ciliata brevipalpa, Polydora ciliata Okuda, Not Johnston, Polydora variegata), which is common symbiotic species for the scallop made 95-100% of total scallop shell bioerosion at the area studied. The muddy bottom sediments enriched by organic matter create favourable conditions for development of microphytobenthos and bacteria, which are predominantly consumed by P. brevipalpa. Linear regressions for the degree of shell bioerosion on the scallop shell height, total wet weight and adductor muscle wet weight revealed negative relationships between them for the scallops inhabiting both sand and muddy sand. The influence of polychaetes on scallops is complex. They may be food competitors. Polychaete can directly affect the host through their boreholes. Scallop expends energy for shell regeneration to prevent the polychaete penetration into its interior cavity. It was found that the degree of shell bioerosion increased considerably with scallop age.

• Mycobiology
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• v.43 no.4
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• pp.444-449
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• 2015

Arbuscular mycorrhizal fungi (AMF) are ubiquitous in the rhizosphere and form symbiotic relationships with most terrestrial plant roots. In this study, four strains of Rhizophagus clarus were cultured and variations in their growth characteristics owing to functional diversity and resultant effects on host plant were investigated. Growth characteristics of the studied R. clarus strains varied significantly, suggesting that AMF retain high genetic variability at the intraspecies level despite asexual lineage. Furthermore, host plant growth response to the R. clarus strains showed that genetic variability in AMF could cause significant differences in the growth of the host plant, which prefers particular genetic types of fungal strains. These results suggest that the intraspecific genetic diversity of AMF could be result of similar selective pressure and may be expressed at a functional level.

• Journal of Korean Institute of Industrial Engineers
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• v.29 no.1
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• pp.14-20
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• 2003

The purpose of this paper is an attempt to analyze the dynamic relationship between KSE and KOSDAQ, two competing markets in Korean stock market, in the viewpoint of competition. Lotka-Volterra model, one of well-known competitive diffusion model, is adopted to represent the competitive situations of Korean stock market and it is estimated using daily empirical index data of KSE and KOSDAQ during 1997~2001. The results show that there existed a predator-prey relationship between two markets in which KSE acted as a predator right after the emergence of KOSDAQ. This interaction was altered to a symbiotic relationship and finally to the pure competition relationship. We also perform an equilibrium analysis of the estimated Lotka-Volterra equations and, as a result, it is found that there is a market index equilibrium point that would be stable in the latest relationship.

• Microbiology and Biotechnology Letters
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• v.50 no.4
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• pp.477-487
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• 2022

Probiotics provide a symbiotic relationship and beneficial effects by balancing the human intestinal microbiota. The relationships between microbiota changes and various diseases may predict health abnormalities and diseases. Treatment with vitamins and probiotics is one therapeutic approach. To evaluate the effect of probiotics on vitamin absorption, we chose Lactobacillus rhamnosus CBT-LR5 treatment, which has resistance to vitamin C-inducible toxicity, with vitamins in high-fat diet (HFD)-induced obesity models. CBT-LR5 affected the absorption of micronutrients, such as ionic minerals and water-soluble vitamins. An increase in vitamin C absorption by CBT-LR5 enhanced the antioxidant response in HFD-induced obesity models. Increased vitamin B absorption by CBT-LR5 regulated lipid metabolism in HFD-induced obesity models. These favorable effects of CBT-LR5 on the absorption of vitamins should be investigated as candidate therapeutic target treatments for metabolic diseases.

• The Korean Journal of Mycology
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• v.50 no.4
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• pp.275-280
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• 2022

Truffles are ectomycorrhizal fungi that belong to the genus Tuber. They exhibit symbiotic relationships, particularly with oak (Quercus spp.) and hazel (Corylus spp.) trees. We performed an inoculation using a spore suspension to synthesize mycorrhizae between European truffles, Tuber borchii and Tuber melanosporum, and an indigenous oak species, Quercus acutissima. This resulted in the formation of mycorrhizae within 2 months after inoculation. Despite having the same host plant, differences in features were observed between Tuber species, including color and mantle type. These results indicate that Q. acutissima is a suitable host plant for truffle cultivation in Korea and provide a better understanding of the mycorrhization of T. borchii and T. melanosporum.

• IMMUNE NETWORK
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• v.24 no.1
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• pp.2.1-2.24
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• 2024

Studies over the last 2 decades have identified IL-17 and IL-21 as key cytokines in the modulation of a wide range of immune responses. IL-17 serves as a critical defender against bacterial and fungal pathogens, while maintaining symbiotic relationships with commensal microbiota. However, alterations in its levels can lead to chronic inflammation and autoimmunity. IL-21, on the other hand, bridges the adaptive and innate immune responses, and its imbalance is implicated in autoimmune diseases and cancer, highlighting its important role in both health and disease. Delving into the intricacies of these cytokines not only opens new avenues for understanding the immune system, but also promises innovative advances in the development of therapeutic strategies for numerous diseases. In this review, we will discuss an updated view of the immunobiology and therapeutic potential of IL-17 and IL-21.

• Animal Bioscience
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• v.37 no.2_spc
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• pp.346-359
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• 2024

Advanced and innovative breeding and management of meat-producing animals are needed to address the global food security and sustainability challenges. Beef production is an important industry for securing animal protein resources in the world and meat quality significantly contributes to the economic values and human needs. Improvement of cattle feed efficiency has become an urgent task as it can lower the environmental burden of methane gas emissions and the reduce the consumption of human edible cereal grains. Cattle depend on their symbiotic microbiome and its activity in the rumen and gut to maintain growth and health. Recent developments in high-throughput omics analysis (metagenome, metatranscriptome, metabolome, metaproteome and so on) have made it possible to comprehensively analyze microbiome, hosts and their interactions and to define their roles in affecting cattle biology. In this review, we focus on the relationships among gut microbiome and beef meat quality, feed efficiency, methane emission as well as host genetics in beef cattle, aiming to determine the current knowledge gaps for the development of the strategies to improve the sustainability of beef production.