• 환경생물
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• 제26권3호
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• pp.183-191
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• 2008

The effect of silver ion solution on the growth of Microcystis aeruginosa UTEX 2388 (cyanobacterium) and Chlorella sp. KCTC AG20136 (green alga) was investigated using separated and mixed culture in filtered natural water and BG11 medium. In separated culture, M. aeruginosa UTEX 2388 and Chlorella sp. KCTC AG20136 were found to be sensitive to 0.01 and 0.1 mg L$^{-1}$ of silver ion, respectively. Also, the silver ion concentrations for the growth inhibition of M. aeruginosa UTEX 2388 and Chlorella sp. KCTC AG20136 in the mixed culture were same in separated culture. Cyanobacteria were more sensitive to the silver ion solution than green algae. In bloom sample, the minimal inhibition concentration of silver ion solution for the low Chl-${\alpha}$ sample (110$\sim$190 ${\mu}g$ L$^{-1}$) and high Chl-${\alpha}$ sample (1,500$\sim$1,900 ${\mu}g$ L$^{-1}$) was about 0.1 and 3.0 mg L$^{-1}$, respectively. The silver ion concentration for the inhibition of algal bloom sample was affected by the algal biomass. In order to use silver ion solution for the control of algal bloom, the silver ion concentration must be determined in consideration of a minimal effect on the environment.

• 대한수의학회지
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• 제51권3호
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• pp.177-183
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• 2011

The radioprotective efficacy of a methanol extract of the red algae Polyopes lancifolia (Harvey) kawaguchi et wang (mPL) was evaluated in mice subjected to total-body gamma irradiation. mPL protection against radiation-induced oxidative stress was examined by histological evaluation of intestinal crypt-cell survival and liver activities of the antioxidant enzymes superoxide dismutase (SOD) and catalase (CAT). mPL (100 mg/kg body weight) administered intraperitoneally at 24 h and 1 h prior to irradiation protected jejunal crypt cells from radiation-induced apoptosis (p < 0.01). The pretreatment of mPL attenuated a radiation-induced decrease in villous height (p < 0.05), and improved jejunal crypt survival (p < 0.05). The dose reduction factor was 1.14 at 3.5 days after irradiation. Treatment with mPL prior to irradiation resulted in significantly higher (p < 0.01) levels of SOD and CAT activities, compared to those levels of irradiated control mice with vehicle treatment. These results suggest that mPL is a useful radioprotective agent capable of defending intestinal progenitor cells against total-body irradiation, at least in part through mPL antioxidative activity.

• 한국환경과학회지
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• 제18권10호
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• pp.1065-1070
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• 2009

Experimental design for ecological restoration approach was investigated from the P' company's slag dumping area with higher pH value. The degree of pH recovery was measured by the injection of carbon dioxide from the LNG exhaust gas, and the residual carbon, for example, calcium and carbonate which can be controlled by artificial seaweed beds. The degree of adaptability from 3 algaes (Undaria pinnatifida, Sargassum horneri and Ecklonia stolonifera) and uptake nutrient function of Ecklonia stolonifera chosen in the first treatment were measured in the laboratory to determine the transplanting algae in artificial seaweed beds. The higher value of pH was decreased to 7.0~8.5 by injection of LNG exhaust gas with flow rate $20\;m^3/min$. In the experiment design at laboratory, the upper part of frond of Undaria pinnatifida and Sargassum horneri began to decay, and the color changed after 10 days. However, those of Ecklonia stolonifera were after 14~20 days. The uptake rate of nutrient from Ecklonia stolonifera was higher than those of other algaes, and those was similar pattern in the control (e.g. seawater); The DIN concentration uptake of Ecklonia stolonifera was $1.88\;{\mu}g/L/hr$ avg. in leachate, but $2.19\;{\mu}g/L/hr$ avg. in seawater. However, the ${PO_4}^3$-P concentration uptake was $0.18\;{\mu}g/L/hr$ avg. in leachate, but $0.31\;{\mu}g/L/hr$ avg. in seawater. These result indicated Ecklonia stolonifera uptaked these nutrients in the leachate as well as in seawater, and it may suggested for this species to transplant for constructing artificial seaweed beds.

• KSBB Journal
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• 제19권1호
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• pp.1-11
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• 2004

클로렐라는 생물화학적 성분들을 풍부하게 함유하고 있어서 영양학적으로 사료나 식품으로 이용되며 화장품, 의약품, 심지어 연료로도 이용되고 있다. 클로렐라는 보통 연못이나 호수 등 담수에서 생육하며, 구형 단세포이다. 생식은 무성생식으로 하루에 4-16배로 증식한다. 클로렐라의 대량생산을 위한 배양은 크게 옥외배양법과 발효조 배양법으로 나뉜다. 클로렐라는 필수 아미노산과 생체에 여러 가지 생리적 기능을 수행하는 지방산과 스테롤, 유산균 성장 촉진 원인 물질인 chlorella growth factor (CGF)의 함유되어 있으며, 생체 내에서 중금속 배출기능, 독성물질의 분해, 동맥경화 및 간장장애의 억제, 면역기능 강화, 항암 활성, 장내 유효세균의 증식 촉진, 식품의 풍미 향상 및 보습효과 등의 기능성을 가지고 있어 기능성 생물소재로 주목되고 있다. 클로렐라는 건강기능식품, 화장품, 의약품 소재로서 응용될 수 있을 뿐만 아니라 이산화탄소의 고정화와 수소가스의 생성 등 환경 및 에너지의 생산을 위한 수단으로서의 역할이 전망된다.

• Asian-Australasian Journal of Animal Sciences
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• 제31권4호
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• pp.556-563
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• 2018

Objective: Spirulina has been recognized formerly as a filamentous spiral-shaped blue- green algae but more recently as a genus of photosynthetic bacteria (Arthrospira). This microorganism is considered as a rich source of essential nutrients for human and animals. The present study was conducted to determine potential application of Spirulina for heat- exposed broilers. Methods: Two hundred and fifty Cobb 500 chicks with male to female in equal ratio with average initial weight of 615.6 g at 17 days of age were divided into 5 treatments with 5 replicates of 10 chicks. Treatment groups were as follows: positive and negative controls with 0% Spirulina supplement and three Spirulina receiving groups with 5 g/kg (0.5%), 10 g/kg (1%), and 20 g/kg (2%) supplementation. Spirulina receiving groups as well as positive control were exposed to high ambient temperature at $36^{\circ}C$ for 6 h/d from 38 to 44 days of age. Biochemical variables were measured in serum samples at 35, 38, 42, and 45 days of broiler chickens age. Results: The results showed that supplementation of the diet with Spirulina decreased concentration of stress hormone and some serum lipid parameters while enhanced humoral immunity response and elevated antioxidant status whereas it didn't meaningfully affect performance characteristics. Nevertheless, feed conversion ratio was improved numerically but not statistically in broilers fed with 1% Spirulina under high ambient temperature. Conclusion: Overall, the present study suggests that alleviation of adverse impacts due to high ambient temperature at biochemical level including impaired enzymatic antioxidant system, elevated stress hormone and lipid profile can be approached in broiler chickens through supplementation of the diet with Spirulina platensis.

• Fisheries and Aquatic Sciences
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• 제17권3호
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• pp.345-353
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• 2014

Copper has been widely used to control algae and pathogens in fish culture ponds. However, its toxic effects on fish depend not only on its concentration in the water but also on the water quality. A laboratory experiment was conducted to assess copper toxicity in the black rockfish Sebastes schlegeli using a panel of antioxidant enzymes, including glutathione (GSH), glutathione S-transferase (GST), glutathione peroxidase (GPx), glutathione reductase (GR) and superoxide dismutase (SOD), at different levels of copper at three water temperatures (WT, 18, 23, $28^{\circ}C$) for 4 days. After exposure to two copper concentrations (100 and $200{\mu}g/L$), GSH levels and GST activities increased significantly, depending on WT (P < 0.05) in the liver, gill, and kidney of the black rockfish. GPx and SOD activities decreased significantly with both increasing WT and copper treatment in the organs of black rockfish (P < 0.05). These changes can be seen as initial responses to temperature stress and as a sustained response to copper exposure. This also indicates that GSH and related enzymes activities were sensitive indexes to stress by toxicants such as copper. The present findings suggest that simultaneous stress due to temperature change and copper exposure can accelerate changes in enzymes activities in the black rockfish. This provides another example of synergism between environmental temperature and pollutants, which may have important implications for the survival of fish in polluted environments during seasonal warming and/or global climate change.

• Journal of Microbiology and Biotechnology
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• 제25권1호
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• pp.109-118
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• 2015

Open raceway ponds are cost-efficient for mass cultivation of microalgae compared with photobioreactors. Although low-cost options like wastewater as nutrient source is studied to overcome the commercialization threshold for biodiesel production from microalgae, a cost analysis on the use of wastewater and other incremental increases in productivity has not been elucidated. We determined the effect of using wastewater and wavelength filters on microalgal productivity. Experimental results were then fitted into a model, and cost analysis was performed in comparison with control raceways. Three different microalgal strains, Chlorella vulgaris AG10032, Chlorella sp. JK2, and Scenedesmus sp. JK10, were tested for nutrient removal under different light wavelengths (blue, green, red, and white) using filters in batch cultivation. Blue wavelength showed an average of 27% higher nutrient removal and at least 42% higher chemical oxygen demand removal compared with white light. Naturally, the specific growth rate of microalgae cultivated under blue wavelength was on average 10.8% higher than white wavelength. Similarly, lipid productivity was highest in blue wavelength, at least 46.8% higher than white wavelength, whereas FAME composition revealed a mild increase in oleic and palmitic acid levels. Cost analysis reveals that raceways treating wastewater and using monochromatic wavelength would decrease costs from 2.71 to 0.73 $/kg biomass. We prove that increasing both biomass and lipid productivity is possible through cost-effective approaches, thereby accelerating the commercialization of low-value products from microalgae, like biodiesel.

• Journal of Microbiology and Biotechnology
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• 제16권2호
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• pp.240-246
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• 2006

Cyanobacteria are present abundantly in rice fields and are important in helping to maintain rice fields fertility through nitrogen fixation. Many rice fields soil contain a high density of cyanobactera, and over 50% of cyanobacterial genera that are in existence in rice paddy fields are heterocystous filamentous forms. A total of 142 isolates of heterocystous filamentous cyanobacteria were screened from 100 soil samples taken from rice paddy fields in 10 different locations across Korea, classified according to their morphological characteristics under light microscopy, and their susceptibly to fungicides examined. The collected blue-green alga were classified into a total of 14 genera, including seven genera of filamentous cyanobacteria and seven genera of nonfilamentous cyanobacteria. In particular, 142 heterocystous filamentous cyanobacteria were isolated and classified into six genera, including Anabaena, Nostoc, Calothrix, Cylindrospermum, Nodularia, Scytomena, and Tolypotrix. Yet, over 90% of the heterocystous filamentous cyanobacteria isolated from the rice paddy fields belonged to two genera: Anabaena and Nostoc. The response of 129 $N_2-fixing$ cyanobacterial isolates, 53 Anabaena and 76 Nostoc, to 10 fungicides was then investigated. The results showed that the Nostoc spp. were more tolerant of the ten tested fungicides than the Anabaena spp., and among the ten tested fungicides, benomyl showed the highest acute toxicity to Anabaena spp. and Nostoc spp. In conclusion, although benomyl is a very useful agent to control phytopathogenic fungi, the application of this fungicide to rice fields should be considered because of its toxicity to the heterocystous filamentous cyanobacteria.

• 한국물환경학회지
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• 제33권1호
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• pp.15-33
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• 2017

Based on the existing pollutant emissin standards which are armed at the pollutant concentration of each pollution source, government formulated and implemented new management system of total water pollutant emission. By virtue of this new management system, pollution loading amount of individual watershed could be controlled, which achieved the requirement of water quality management such as TP and BOD. In initiate stage of it's implement, BOD was selected as object of water quality management, While it's necessary to consider the continuity of water quality data and established pollutant management laws and policy. During the ongoing management, TP management was added into the system while simply BOD management was not enough. However, the frequency of algae bloom in Han-river showed a trend of same, even though TP was treated as additional control target. Therefore, this paper will analyze different water quality parameters and characteristic of water quality, so that this study can be provide as reference for watershed management of water quality, by which the applicable management period and target pollutant can be selected in the future.

• 한국환경복원기술학회지
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• 제20권4호
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• pp.1-13
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• 2017

The purpose of this study is to analyze a term of decade of water quality data of the Mulgum intake station on the Nakdong river(dam) to find the cause of algal blooms and to set an alternative to prevent artificial lake water pollution. Our study shows that water quality changes have regular periodic regularity and there was a certain correlation between specific analytical items. According to the analysis results of each factor, the decline in precipitation was not the main reason for algal blooms. TP concentration had a slight effect on Chl-a concentration but was not a limiting nutrient of a bloom. TN concentration had a strong correlation with Chl-a and strongly negative correlation with temperature, but was not a bloom's limiting nutrient, and was only a dependent variable. As the temperature was negatively correlated with the Chl-a concentration, it is found that the aspect of the ecological influence of the temperature was the most important factor of the phytoplankton concentration change. The N/P ratio lies under a power function with a high degree of reliability by the TP concentration, and the phenomenon appeared to be the same as the results of two other comparative areas. This result confirms that TN is dependent on TP and the biota in the lake that TN is a dependent variable whose concentration is determined by TP it. In conclusion, the increase in lake bloom is the result of a food chain change, and it is necessary to control the ecosystem by the food chain in the lake in order to reduce the lake's bloom. In particular, it is important to keep the benthic ecosystem as wide as possible in the aerobic state.