• Korean Journal of Ecology and Environment
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• v.34 no.2 s.94
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• pp.133-139
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• 2001

For elucidating the effective management for nutrients removal by the phytoplankton growing at the effluents of night soil and sewage treatment plant, the dilution rates, physical operation conditions and duration of culture were defined. For nutrients removal from effluent of night soil treatment plant, lower the dilution was better, and Scenedesmus sp. was dominant. For removal from the effluent of sewage treatMent plant, the proper operation conditions were 50% of dilution rate, stirring and 2 days culturing. With these conditions, the removal rate of TKN was 88%, DIP$70{\sim}80%$ and the chlorophyll concentration reached at $1,300\;mg/m^3$ chlorophyll a concentration. the variation of chlorophyll a was highly corrrlated with ammonia ($r^2\;=\;0.96$) and DIP ($r^2\;=\;0.92$).

• Journal of Environmental Science International
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• v.4 no.3
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• pp.167-176
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• 1995

A study on phytoplankton community was carried out from June, 1992 to May, 1993 at selected stations in Hoedong Reservoir. The phytoplankton are identified as 176 taxa including 5 phylum, 67 genera. The important species in this reservoir were Asterionella formosa, C meneghiniana, Dictyosphaerium plilchellum, Fragilaria crotonensis, Melosira distans, M grantulata, M. granulata var. angustissima, M. granulate var. angntissima f. spirdis, Micractinium pussillum, Microcystis aeruginosa, Pundorina morn, Pediastrum boryanum, P. duplex, Peridinium sp., Scenedesmus quadriauda, Synedra acus, S. rumpens and S. ulna. The causative species of water bloom were identified as Microcystis aeruginsa, Trahellomonas hispida, Ceratium hirwdinella, Peridinium sp., Melosira italica, Staurastrum dorsidentiferum var. onatum in the area. During the study periods standing crcps of phytoplankton were maximum in August, 1992 and minimum in December 1992. The species dominance index and diversity index were ranged 24.7-99.9, 0.001-3.06, respectively. Key Words : phytoplankton community, causative species of water bloom, standing crops. dominance index, species diversity index.

• Korean Journal of Environmental Biology
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• v.32 no.1
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• pp.26-34
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• 2014

Due to the rapid energy consumption and fossil fuel abundance reduction, the world is progressively in need of alternative and renewable energy sources such as biodiesel. Biodiesel from microalgae offers high hopes to the scientific world for its potential as well as its non-competition with arable lands. Taking consideration to reduce the cost of production as well as to attain twin environmental goals of treatment and use of animal waste material the microalgal cultivation using piggery manure has been tested in this study. Unialgal strains such as Chlorella sp. JK2, Scenedesmus sp. JK10, and an indigenous mixed microalgal culture CSS were cultured for 20 days in diluted piggery manure using Small Scale Raceway Pond (SSRP). Biomass production and lipid productivity of CSS were $1.19{\pm}0.09gL^{-1}$, $12.44{\pm}0.38mgL^{-1}day^{-1}$, respectively and almost twice that of unialgal strains. Also, total nitrogen and total phosphorus removal efficiencies of CSS was 93.6% and 98.5% respectively and 30% higher removal efficiency compared to the use of unialgal strains. These results indicate that the piggery manure can provide microalgae necessary nitrogen and phosphorus for growth thereby effectively treating the manure. In addition, overall cost of microalgal cultivation and subsequently biodiesel production would be significantly reduced.

• ALGAE
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• v.18 no.4
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• pp.255-262
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• 2003

Ecological characteristics of phytoplankton communities were investigated biweekly at 6 stations from Feb. 2001 to Feb. 2002 at the lower part of the Han River. During the study, a total of 267 taxa which were composed of 114 green algae, 104 diatoms, 22 blue-green algae, 13 chrysophytes and 2 dinoflagellates were observed. The standing crops of phytoplankton communities were ranged from 1.30 ${\times}10^6$ cells ${\cdot}l^{-1}$ to 37.47 ${\times}10^6$ cells ${\cdot}l^{-1}$. The dominant species were 11 taxa including Pediastrum duplex, Scenedesmus quadricauda in green algae, Osillatoria limosa, Microcystis aeruginosa, Merisomorpedia sp., Phormidium sp. in blue-green algae, and Asterionella gracillima, Aulacoseira granulata, Fragilaria crotonensis, Stephanodiscus hantzschii f. tenuis, Synedra acus in diatoms. Asterionella gracillima and Stephanodiscus hantzschii f. tenuis were abundant at every station from winter to spring. Stephanodiscus hantzschii f. tenuis occupied the highest dominant ratio and standing crop. From summer to autumn, dominant species were Aulacoseira granulata at all stations and blue-green algae such as Osillatoria limosa, Microcystis aeruginosa, Merisomorpedia sp. at some stations. These 4 species were mostly present at the lower stations 4, 5, 6 and very few at the upper stations 1, 2, 3.

• Journal of Ecology and Environment
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• v.29 no.5
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• pp.433-438
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• 2006

To elucidate the mechanisms by which algal food quality affect Daphnia growths, we measured carbon incorporation rates and respiration rates of Daphnia magna with Cryptomonad Rhodomonas minuta, green algae Scenedesmus acutus and cyanobacteria Synechococcus sp. with varying physiological states as food. Carbon assimilation rates were high with R. minuta and S. acutus and low with Synechococcus sp. showing a similar pattern to the growth rate pattern. There was no clear difference among respiration rates of three algal species. Carbon assimilation rates and respiration rates of D. magna appeared to be independent on Molar C:P ratios in algal foods. Carbon growth efficiencies (incorporated carbon per assimilated carbon amount) were lower when D. magna fed with Synechococcus sp. than fed with R. minuta or S. acutus. Analysis of variance results show that carbon assimilation rates which were sum of incorporation and respiration rates and carbon growth efficiencies were only dependant on species affiliation. Overall, our results showed that algal species with varying ${\omega}3$ polyunsaturated fatty acid content led different carbon incorporation rates and overall carbon assimilation rates of D. magna.

• Journal of Microbiology and Biotechnology
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• v.29 no.1
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• pp.59-65
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• 2019

Fusaricidin analogs, produced by Paenibacillus polymyxa, were tested for selective control of a major bloom-forming cyanobacterium, Microcystis sp. Fusaricidin (A and B mixtures) and four analogs were isolated from P. polymyxa E681 and investigated for their inhibition of cyanobacterial cell growth. Among the four fusaricidin analogs, fraction 915 Da (designated as Fus901) showed growth inhibition activity for Microcystis aeruginosa but not for Anabaena variabilis and Scenedesmus acutus. Microcystin concentration decreased up to 70% and its content per cell also decreased over 50% after 3 days. Fusaricidin exhibited growth inhibition against Gram-positive bacteria but Fus901 did not. Molecular weights of fusaricidin A and B were 883 Da and 897 Da, whereas that of Fus901 was 915 Da. Structure analysis by a ring-opening method revealed a linear form for Fus901. Expression of the pod gene related to oxidative stress was increased 2.1-fold by Fus901 and that of mcyD decreased up to 40%. These results indicate that Fus901 exerts oxidative stress against M. aeruginosa. Thus, Fus901 can be used as a selective cyanobactericide without disturbing the ecological system and could help in decreasing the microcystin concentration.

• Journal of Environmental Health Sciences
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• v.8 no.1
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• pp.1-11
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• 1982

A study on the water pollution of Gumho river by the relationship between physio-chemical conditions and water quality level by phytoplankton was examined at 7 sampling positions during the period from Aug. 1 to Nov. 30, 1981. Examination of physio-chemicat water analysis such as temperature, pH, DO, BOD, and biological analysis are as follows: 1. pH was in the range of 6.6-7.3. 2. At all positions DO was0.5-11.9 mg/l. But at Shinchun bridge and Gangchang was 0.5-3.9 mg/l. 3. BOD was in the range of 3.4-29.2 mg/l. Banyawol, Dongchon and Gumdan was shown good condition. But at Shinchun bridge was 21.1-29.2 mg/l. 4. The plankton identification in this study period showed, Cyanophyceae is 7 genera 13 species, Bacillariophyceae is 11 genera 32 species, and Chlorophceae is 17 genera 27 species: total 35 genera 72 species. 5. In the point of phytoplankton classification, upper stream of Banyawol, Dongchon and Gumdan which BOD was 3.4-8.7 mg/l, dominant phytoplanktons were Synedra ulna, Ulothrix sp., Oscillatoria sp. and Frusturia rhomboides. At Shinchun bridge which BOD was 21.1-29.2 mg/l, Microcystis aeruginosa, Closterium acerosum and Oscillatoria sp were found a small. At 3rd gongdan which BOD was 9.2-12.5 mg/l, dominant species were Synedra ulna, Hormidium sp and Actinastrum hantzschii. At Paldal which BOD was 7.8-9.2 mg/l, dominant species were Nitzschia palea, Synedra ulna and Scenedesmus bijuga. At Gangchang of down stream which BOD was 6.9-9.2 mg/l, dominant phytoplanktons were Closterium acerosum, Microcystis aeruginosa and Actnastrum hantzschii. 6. The results of biological water analysis by saprobic system were as follows: Banyawol was from oligosaprobic to $\beta$-mesosaprobic, Dongchon and Gumdan was from $\beta$-mesosaprobic to $\beta$-mesosaprobic, Shinchun bridge was polysaprobic, 3rd gongdan was from $\alpha$-mesosaprobic to $\beta$-polysaprobic, Paldal was $\beta$-polysaprobic and Gangchang was $\alpha$-polysaprobic.

• Proceedings of the Korean Environmental Sciences Society Conference
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• 2003.11b
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• pp.241-244
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• 2003

2000년에 발생한 12호 태풍(Prapiroon)에 의한 성층 호수의 식물플랑크톤 군집 변화양상을 주암호의 복교지점에서 2000년 8월 30일부터 9월 29일 까지 조사하였다. 프라피룬은 복교지점에서 초속 40m의 강풍을 동반하였는데, 이 물리력은 성층으로 인해 불연속적 층을 형성하고 있던 수괴 전체를 혼합시켰다. 수체의 혼합은 격리로 인해 이질적 환경과 생물조성을 이루고 있던 층간의 혼합을 유도하여 식물플랑크톤의 우점 분류군, 종조성, 우점종을 교체시키는 요인으로 작용한 것으로 추측되었다. 식물플랑크톤의 우점 분류군은 태풍 이전의 규조류에서 녹조류로 교체되었고, 후에 남조류로 교체되었다. 우점종은 태풍 이전에는 Melosira granulata였으나 태풍 이후에는 Scenedesmus spp.와 Staurastrum sp.가 우점하는 것으로 나타났다. 개체수의 밀도는 태풍에 의한 변화가 크지 않았다. 태풍에 의해 파괴되었던 성층은 태풍 이후 재성층화 되기 시작하여 6일째엔 안정된 성층이 관찰되었다. Secchi depth는 태풍에 의해 많이 감소하였으나 수체가 안정화되면서 다시 증가하는 양상을 나타냈다. 결론적으로 태풍은 여름의 성층으로 분리된 수괴를 혼합시킬 수 있는 물리력을 가져 수서 생태계 내 생물의 동태에 영향을 미칠 수 있음을 알 수 있다.

• Journal of Korean Society of Water and Wastewater
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• v.18 no.2
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• pp.247-253
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• 2004

Major species of Lake Deganuma has varied depending on the season. Namely, there are Micractinium pusillum, chlorella., Scenedesmus sp. shown up in spring season, Microcystis aeruginosa, Microcystis wesenbergii, Anabena spiroides in summer and autumn season and Cyclostephanos invisitatus, Diatoma in winter season in the Lake. As the number of plankton increased, the zeta potential on their surface of them decreased. For this reason, they were dispersed in the lake though the population increased. Zeta potential of M. aeruginosa showed -20mV when their outer size got smaller. As for coagulant dosing in DAF, large amount of coagulant was effective to get lots of sludge during water treatment.

• Korean Journal of Ecology and Environment
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• v.41 no.3
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• pp.402-411
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• 2008

Grazing effects of two freshwater shellfish, Unio douglasiae (UNIO) and Cipangoplaudina chinese malleata (CCM), on the hibernal diatom communities in eutrophic water was examined in a laboratory. Two animals having different feeding types used in the study were collected from Keum River (Boryeong, Korea), acclimatized in the artificial management system in a laboratory over at least one month, and starved in a laboratory for 2 days before the experiment. Experimental waters, which dominated by Synedra ulna-Scenedesmus sp. (ca. 80%), was collected from eutrophic lake, Lake Ilgam (Seoul) in Feb., 19, 2008 at AM 10:00, and used in the study after the filtration with 1 mm Nylon mesh. Feeding experiments were largely divided into three kinds of animal treatments; five densities of UNIO (U0, U1, U2, U3, U4) and CCM (C0, C1, C2, C3, C4), and four combined densities of two shellfish (M0, M1, M2, M3). U0 and C0 were control (no addition of UNIO or CCM), U1 or C1 (each animal density at 0.5 ind. $L^{-1}$), U2 or C2 (1.0 ind. $L^{-1}$), U3 or C3 (1.5 ind. $L^{-1}$), and U4 or C4 (2.0 ind. $L^{-1}$), respectively. Four combined treatments were consisted of M0 (no animals), M1 (U1+C3), M2 (U2+C2), and M3 (U4+C1), respectively. Under the presence of animal, the concentration of Chl-a and algal abundance were clearly decreased with the increase of UNIO density and the treated time, while in combined group a strong decrease of algal density showed with the increase of UNIO density. Total phytoplankton density shifted as the similar patterns to that of Chl-a concentration (r=0.6527, p<0.0001), however, there showed the differences following a species. There were strong decreases of dominant species Synedra ulna, Scenedesmus sp., Ankistrodesmus falcatus in UNIO treatment group, Diatoma vulgare in combined group, while Cryptomonas ovata in high density of CCM increased about 20% in algal density. Grazing rates (GRs) based on the concentration of Chl-a was depend on the kind of shellfish and treatment time; a strong feeding of CCM showed in the initial stage, and four hours later, UNIO and combined group with high UNIO density showed the high GRs. Interestingly, faeces production of shellfish was highest in combined group with high density of CCM, while their size over 60 ${\mu}m$ was much higher in production magnitude than that less 60 ${\mu}m$. Collectively, these results suggest that two domestic shellfish and its combined treatment have a strong potential as an effective biological controller of diatom bloom in cold eutrophic waters.