UV Effect of the Antarctic Diatoms under Culture Conditionr

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Phaeocystis antarctica Karsten as an indicator species of environmentalchanges in the Antarctic (in English)

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Cryophilic diatoms Navicula glaciei/perminuta in an Antarctic coastal environment. Algae

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Importance of cold-adapted microalgae in the Antarctic

최근 해빙 미소생물에 대한 연구가 전세계적으로 집중적으로 이루어지고 있다. 여러 가지 이유가 있겠지만 초저온의 극한지 해빙 속에서 생리적, 생화학적으로 적응하면서 살아남을 수 있는 기작을 이해하고, 어떤 물질이 이런 역할을 하는지를 생명공학적인 측면에서 잠재적으로 이용하려는 시도가 이루어지고 있기 때문이다. 현재 산업적으로 이용되고 있는 물질들로는 양식업, 축산업 및 식품의 재료로 PUFAs가 생산되고 있고, 세제나 식품가공을 위해 저온성 효소가 이용되고 있다. 또한 극지의 저온 환경에 적응한 생물들로 추출한 결빙방지물질을 이용한 응용 연구가 많이 진행되고 있다. 극지에서 추출한 결빙방지 단백질을 이용해 식품 저장, 의약 분야에서 초저온 수술, 장기 보관 및 혈액 보관 등에 이용하기 위한 노력이 세계적으로 이루어지고 있다. 기존의 결빙방지 단백질은 자원이 한정되어 있는 극한지의 동물로부터 추출했기 때문에 대량생산의 한계가 있다는 약점이 있다. 그러나 현재 한국해양연구의 극지연구소에서는 극한지 미세조류를 대량으로 배양할 수 있는 시설을 확충하여 새로운 결빙방지 물질을 대량생산할 수 있는 방안을 마련하기 위한 연구가 진행중이다.22othe

1998/1999 남극 킹조지섬 마리안소만 표층수에 서식하는 미세조류의 계절적 변동

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Effects of the Antarctic Ozone Depletion on the Marine Phytoplankton

The Antarctic ecosystem has been affected by continuous ozone depletion. Increase of UV radiation due to the ozone depletion in the Antarctic has changed growth environment for the marine organisms, resulting in various effects on the Antarctic marine ecosystem whether adverse or not. Especially, fast growing primary producers, phytoplankton which use solar light as energy source are the most sensitively affected organisms against the UV increase. The UV radiation increase may result in change of the productivity, biomass, and species composition of phytoplankton. In addition, UV radiation could cause physiological, genetic, and ecological changes of phytoplankton cells. It is necessary to accumulate baseline data which will be compared with the future data to estimate the degree of changes in the Antarctic marine ecosystem. The Antarctic phytoplankton which have adapted for a long time to the extreme environment can be used as continuous biological indicator to detect and monitor the environmental changes. We have reviewed recent research papers about effects of the ozone depletion on the Antarctic marine phytoplankton.22Nkciothe

전 지구 환경변화에 대하 극지 식물플랑크톤의 중요성

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UV-B Effects on Growth and Nitrate Dynamics in Antarctic Marine Diatoms Chaetoceros neogracile and Stellarima microtrias

Two isolated Antarctic marine diatoms, Chaetoceros neogracile VanLandingham and Stellarima microtrias (Ehrenberg) Hasle and Sims were examined to show changes of growth and uptake rate of nitrate due to UV-B irradiance. Chlorophyll (chl) a concentration was regarded as the growth index of diatom. The diatoms were treated with UV-B radiation and cultured for 4 days under cool-white fluorescent light without UV-B radiation. Two levels of UV-B exposures were applies: 1 and 6 W m−2. Durations of UV-B treatment were 20, 40 and 60 minutes under 6 W m−2 and 1, 2, 3, 4 and 5 hrs under 1 W m−2. The control groups were cultured at the same time without UV-B radiation. The growth rates of two diatoms decreased under 1 and 6 W m−2 UV-B irradiances than that of control group. After 4 days, chl a concentrations of C. neogracile were increased more than 4 times from 133 μgol−1 to 632 μgol−1 in control group. However, the concentration of experimental groups under 1 W m−2 UV-B were only increased from 139 μgol−1 to 421 μgol−1 during one hour and the chl a concentrations were decreased from 144 μgol−1 to 108 μgol−1 during five hour. Growth of diatom dramatically more decreased under 6 W m−2 UV-B than 1 W m−2 UV-B. The chl a concentration of experimental groups under 6 W m−2 UV-B for one hour was only increased from 111 μgol−1 to 122 μgol−1. In the case of S. microtrias showed also similar pattern to C. neogracile by UV-B radiation. The uptake rates of nitrate by the two strains were decreased abruptly under 6 W m−2 UV-B irradiances. When two strains were treated under 1 and 6 W m−2 UV-B during one hour, the strains were only continued growth and uptake of nitrate under 1 W m−2 UV-B. This experimental evidence shows that exposure to UV-B radiation especially to high irradiance of UV-B decreases diatom survival and causes lower decrease of nutrient concentrations by microalgae in Antarctic water. Furthermore, evidence suggests that microalgal communities confined to near-surface waters in Antarctica will be harmed by increased UV-B radiation, thereby altering the dynamics of Antarctic marine ecosystems.22Nkciothe

Photosynthetic Parameters of Phytoplankton Assemblages in the Surface Water of Maxwell Bay and the Weddell Sea during the 1996/97 Austral Summer

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제주도 서귀포 연안의 백화현상에 대한 생태학적 특성

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