• Journal of Ecology and Environment
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• 제40권1호
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• pp.55-65
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• 2016

Background: In this article, it was analyzed how snow melting affects the assembly of lichen and moss communities in a small area of the coastal region of Barton Peninsula, which is in maritime Antarctic. In the small area, even though there is a huge gap of difference of the environment between the snow-filled area and snow-melt one, the latter did not have distinctive environmental gradients. Results: Depending on the snow melting time, coverage and species diversity of lichens and mosses tend to increase remarkably. For species with significant changes depending on the snow-covered period, there are Andreaea regularis, crustose lichens, Placopsis contortuplicata, Usnea aurantiaco-atra, and snow algae. In this area, the process of vegetation assembly process has shown the directional development in the order of snow algae${\rightarrow}$crustose, lichen sub-formation${\rightarrow}$fruticose lichen, moss cushion sub-formation (Andreaea sociation)${\rightarrow}$fruticose lichen, and moss cushion sub-formation (Usnea sociation), according to the order of snow melting. These directional development stages are shown in gradual change in small area with the snow melting phenomena. However, in the snow-free area, where water is sufficiently supplied, it is expected that moss carpet sub-formation (Sanionia sociation) will be developed. Vegetation development in the small area with the snow melting phenomena, depending on differences of resistance on snow kill and moisture settled by species in according to the time of snow melting, tolerance model to form community is followed. Conclusions: The research results explain the development of vegetation in the Antarctic tundra and its spatial distribution according to the period for growth of lichens and mosses in the summer time by differences of snow melting in the small area. In the future, if research for the community development process in a large scale will be done, it will be helpful to figure out temporal and spatial dynamic of vegetation in the Antarctic tundra where snow and glaciers melt rapidly due to climatic warming.

• Journal of Microbiology and Biotechnology
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• 제18권6호
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• pp.1016-1023
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• 2008

Lichens are predominant and important components of flora in the terrestrial ecosystem of Antarctica. However, relatively few researches on the phylogenetic position of Antarctic lichen-forming fungi have been accomplished. In this study, partial sequences of nuclear large subunit rDNAs from 50 Antarctic specimens were obtained and the phylogeny was reconstructed. Antarctic lichen species were distributed in 4 orders, including the monophyletic order Agyrales, paraphyletic orders Pertusariales and Teloschistales, and polyphyletic order Lecanorales. Species diversity was highest in the order Lecanorales, followed by Teloschistales and Pertusariales. Based on the phylogeny and sequence similarity analyses, it is proposed that the taxonomy of Stereocaulon alpinum, Physcia caesia, Usnea aurantiacoatra, and Cladonia species should be revised by careful examination of their phenotypic and molecular characteristics. Six species known to be endemic to Antarctica, Catillaria corymbosa, Himantormia lugubris, Leptogium puberulum, Pertusaria pertusa, Rhizoplaca aspidophora, and Umbilicaria antarctica, formed unique lineages, implying independent origins in the Antarctic area.

• 한국균학회소식:학술대회논문집
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• 한국균학회 2006년도 추계학술대회 및 정기총회
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• pp.24-28
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• 2006

Author have studies lichen flora of the most important ice-free areas of Continental Antarctic: Bunger Hills, and the vicinity of Prudz Bay (Larsemann Hills, and Radok Lake in Prince Charles Mountains). Totally 44 lichen species from 22 genera were reported for Bunger Hills and 50 lichen species from 22 genera and 10 families: Acarosporaceae, Lecanoraceae, Lecideaceae, Parmeliaceae, Pertusariaceae, Physciaceae, Rhizocarpaceae, Stereocaulaceae, Theloschistaceae, and Umbilicariaceaewere reported for the Prudz Bay Region. 20 lichen species were found in the region for the first time. Phytogeographic analysis indicated a relatively high proportion of species with bipolar distribution - about 50% of recorded lichen species. About 30% of lichens normally don't extend into maritime zone occurring in continental Antarctic only. The most common lichen families in the region are Buelliaceae, Lecanoraceae and Teloschistaceae. The water supply and not a temperature is the critical factor for lichens in the Continental Antarctic. Moisture appears to be supplied for lichens not only from snow-melt water but mainly from air. In Maritime Antarctic, due to high air humidity macrolichens form communities everywhere (Himantormia, Usnea and Umbilicaria). In oases of Continental Antarctic extensive sites are lacking in lichen cover, even if the ground is normally snow free. Lichens occur at humid sites with moisture which were brought by winds over the ice cap and poorly developed or absent in dry areas. Of particular significance for lichens are substrate characteristics, animals influence and salinity brought by wind in coastal areas. Most rich lichen vegetation developed in oases around nests of snow petrels, where the melt water is enriched by nutrients. In contrast, the most pure vegetation is on mobile sand and gravel and in salted coastal habitats.

• 생약학회지
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• 제47권2호
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• pp.122-127
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• 2016

Methicillin-Resistant Staphylococcus aureus(MRSA) is a multidrug-resistant(MDR) strain. (+)-Usnic acid(UA) is uniquely found in lichens, and is especially abundant in genera such as Usnea and Cladonia. UA has antimicrobial activity against human and plant pathogens. Therefore, UA may be a good antibacterial drug candidate for clinical development. In search of a natural products capable of inhibiting this multidrug-resistant bacteria, we have investigated the antimicrobial activity of UA against 17 different strains of the bacterium. In this study, the effects of a combination of UA and permeable agents against MRSA were investigated. For the measurement of cell wall permeability, UA with concentration of Ethylenediaminetetraacetic acid(EDTA) was used. In the other hand, Sodium azide($NaN_3$) was used as inhibitors of ATPase. Against the 17 strains, the minimum inhibitory concentrations(MICs) of UA were in the range of $7.81-31.25{\mu}g/ml$. EDTA or $NaN_3$ cooperation against MRSA showed synergistic activity on cell wall. UA and in combination with EDTA and $NaN_3$ could lead to the development of new combination antibiotics against MRSA infection.