• Journal of Wetlands Research
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• v.19 no.4
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• pp.508-514
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• 2017

Water-bloom and red tide due to eutrophication have been overgrown and have caused various environmental problems. Recently, however, research on bid-diesel that can utilize algae as an energy source has been actively carried out. In particular, many studies variously have been conducted to utilize algal photosynthesis oxygen as a supply method for reducing the energy by an air blower in MWTP. In this study, a lab scale algae-nitrification reactor was operated to replace the oxygen required for nitrogen removal and the operation period was largely divided into three sections. In the first section, ammonia nitrogen removal efficiency was 24 ~ 38% according to the MLSS (Mixed Liquer Suspended Solid) concentration. In the second section, ammonia nitrogen removal efficiency was 38 ~ 50% according to the micro-algae concentration and in the last section ammonia nitrogen removal efficiency was 61 ~ 80% according to HRT (Hydraulic Retention Time). As a result, as the MLSS decreased and algae biomass increased, the ammonia nitrogen removal efficiency tended to increase, but the effect of Algae biomass was greater than that of MLSS.

• Fisheries and Aquatic Sciences
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• v.1 no.2
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• pp.250-254
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• 1998

Harmful micro algae isolated from Korean coastal waters, were tested with FITC-conjugated lectins and observed by epifluorescent microscopy to distinguish each other. Strain-specific sugar composition at the cell surface was suggested by the affinity of lectins to different microalgae. The micro algae Cochlodinium polykrikoides (CP-1) and Gymnodinium $A_3\;(GA_{3-1}\;1)$, are morphologically similar, but exhibited different binding activity with the lectins ECA, HPA and WGA. In Peridiniales, the micro alga Alexandrium tamarense (AT) bound HPA and WGA, but Scrippsiella trochoidea (ST-1) did not bind those lectins. Three species of Prorocentrum also exhibited different binding specificity with HPA, PHA and SBA. A non­toxic Korean isolate of Heterosigma akashiwo (HA-2) bound ConA, PEA and UEA. These results suggest that lectins are useful in discriminating morphologically similar species, as well as different species or strains within the same genus.

• Journal of Korean Society of Water and Wastewater
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• v.27 no.5
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• pp.621-629
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• 2013

Since algae had been issued an environmental problem, water blooms, deepened due to increase of retention water basin in Korea as well as a biomass resource for producing biofuel, this study conducted a series of experiments for Spirulina platensis using the flotation process with micro-bubble. To elevate utilization of collected-algae, this study focused on omitting or minimizing coagulant's doses as changing a cultivation period and condition affected on physical property change of algae. Two coagulants, PAC and Chitosan, were used to test the collecting rate of algae and the result found no difference between two rates. For flotation experiments without adding the coagulant, dried algae weight (passing 14 days after cultivation for 20 days) detected high separation efficiency 98.2 % and it (passing 7 days after long-term cultivation for 28 days) presented good separation efficiency 91.9 %. Chlorophyll's separation efficiency showed a similar tendency with the case of the dried algae weight. In endogeny conditions, a light source and a carbon source were not considerably affected on the flotation separation efficiency. Thus, this study confirms that algae biomass may be collected without the coagulant during the endogeny condition period after enough cultivation time, 3 weeks.

• Advances in nano research
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• v.3 no.4
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• pp.243-255
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• 2015

In this investigation, ecotoxicity of nano and micro metal oxides, namely silica ($SiO_2$) and alumina ($Al_2O_3$), on the growth of green algae (Porphyridium aerugineum Geitler) is discussed. Effects of nano and micro particles on the growth, chlorophyll content and protein content of algae are analysed using standard protocols. Results indicate that $SiO_2$ nano and micro $SiO_2$ particles are non-toxic to P. aerugineum Geitler up to a concentration of 1000 mg/L. In addition, $Al_2O_3$ microparticles are less toxic to P. aerugineum Geitler, whereas $Al_2O_3$ nanoparticles are found to be highly toxic at 1000 mg/L. Moreover, $Al_2O_3$ nanoparticles decrease the growth, chlorophyll content, and protein content of tested algae. In addition, zeta potential and contact angle are also important in enhancing the toxicity of metal oxide nanoparticles in aquatic environment. This study highlights a new insight into toxicity evaluation of nanoparticles on beneficial aquatic organisms such as algae.

• Korean Journal of Environmental Biology
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• v.30 no.1
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• pp.71-76
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• 2012

Spills of $M/V$ Hebei Spirit on $7^{th}$ December 2007 caused a seriously damage to the ecosystem of Korean coast. Of these, microbial communities (i.e., attached benthic micro-algae) were reported to be sentive to the environmental change so it can be used for ecological risk assessment. Our experiment was designed to examine the ecological risk assessments for oil pollutant using benthic attached algal community on the artificial substrates of acrylic plates. Field monitoring in the culture system was conducted in Jangmok Bay. The abundances of attached micro-algae on artificial substrates gradually increased with increasing of sampling times. Among them, diatoms were the most important colonizer of coastal water, with the genera $Cylindrotheca$ and $Navicular$ most abundant. In particular, developed the culture system has correctly measured qualitative and quantitative abundance of attached micro-algae because same acrylic plates as artificial substrates were used. Thus, this culture system may be directly applied to the ecological risk experiments of microbial community structure from oil pollutants.

• ALGAE
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• v.23 no.2
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• pp.91-114
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• 2008

Fifty seven taxa of Cyanobacteria and 15 taxa of Chlorophyta were recorded from the exterior of buildings and rock surfaces of monuments in different regions in India. Four cyanobacteria, e.g. Chroococcidiopsis kashayi, Pseudophormidium indicum, Plectonema puteale and Scytonema geitleri, and the green alga Trentepholia abietina var. tenue occur on the sub-aerial habitats throughout the year. In addition, five other green algae: Chlorococcum infusionum, Scenedesmus arcuatus, Trentepholia aurea, Gloeocystis polydermatica and Printzina effusa, and 18 other cyanobacteria taxa of the genera Chroococcus (5), Asterocapsa (1), Cyanosarcina (2), Gloeocapsa (7), Gloeothece (2) and Scytonema (1) occur on the sub-aerial surfaces enduring extreme temperature and desiccation during summer months of the tropics. During the rainy season, the warm and humid climatic regime coupled with availability of moisture supported an additional ten green algae and 29 cyanobacteria in eight and 17 genera, respectively. The green algal genera Klebsormidium, Stichococcus and Trebouxia, which are dominant in temperate regions, did not occur on the sub-aerial habitats in India, however, species of Gloeocapsa, Chroococcus, Chroococcidiopsis, Phormidium, Leptolyngbya, Nostoc, Scytonema, Chlorella and Trentepholia showed global occurrence in similar habitats.

• Fisheries and Aquatic Sciences
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• v.4 no.2
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• pp.75-83
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• 2001

This study is to investigate biochemical compositions of two species of marine microalgae, Chlorella ellipsoidea of Chlorophyta and Tetraselmis suecica of Prasinophyta, and to assess their potential antimicrobial activities. Crude protein, lipid and carbohydrate for C. ellipsoidea were $43.15\%$, $12.63\%$ and $13.09\%$, respectively, and those for T. suecica were $44.95\%$, $4.80\%$ and $24.05\%$, respectively. The major amino acids of the two micro algae were aspartic acid, glutamic acid, glycine, alanine, valine, leucine, lysine and proline, and no significant difference between the amino acid compositions of both micro algae was observed. The major sugars for both microalgae were glucose, galactose and mannose, and glucose contents showed the highest level, $58.70\%$ for C. ellipsoidea and$57.86\%$ for T. suecica. The major mineral contents of both micro algae for 100g were Ca (3,114mg in C. ellipoidea and 3,389mg in T. suecica) and followed by Na (2,881mg), K (548mg) and Mg (545mg) for C. ellipsoidea and Na (1,832 mg), Mg (1,510mg) and K (548mg) for T. suecica. In the content of ATP-related compound, hypoxanthine in C. ellipsoidea and IMP in T. suecica were absolutely dominant compounds. The highest content of fatty acid in C. ellipsoidea was 20:4, $27.15\%$ and that in T. suecica was 18:3 (w-6), $18.10\%$. In case of physiologically important polyunsaturated fatty acids like eicosapentaenoic acid (20: 5) and docosahexaenoic acid (22: 6), both microalgae possessed just trace amounts but was rich in arachidonic acid (20: 4). Vitamin content in both microalgae was significantly high in choline and inositol. In antimicrobial activity by water- and fat-soluble fraction of the micro algae, hexane extract in the fat-soluble fraction of C. elliposidea inhibited the growth of Bacillus subtilis by $96\%$ bactericidal activity and tetrachlorocarbon extract of T. suecica indicated relatively excellent antimicrobial activity $(81\%\;bactericidal\;activity)$ against Escherichia coli. Hot water extract among water-soluble fraction of both micro algae almost suppressed the growth of Staphylococcus aureus by $96\%$ bactericidal activity.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.9
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• pp.3610-3614
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• 2010

Taxonomic compositions and species diversities of the planktonic micro algae communities were investigated 8 times during the period from May, 2006 to November, 2007 in Saemangeum water regions. Total of 191 taxa were observed; 94 diatoms, 31 chlorophytes, 24 dinoflagellates, 24 cyanophytes, 11 euglenophytes, 3 silicoflagellates, 1 cryptophyte and 3 unidentified microflagellates. During the period of this study, diversity indices of the community were changed spatio-temporally and fluctuated irregularly. It was surmised that artificial factors to the water condition such as open and lock of the dike stressed to the planktonic micro algal groups.

• Journal of the Korean Society for Marine Environment & Energy
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• v.19 no.4
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• pp.341-348
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• 2016

Micro-algae, one of the biological resources for alternative energy, has been heavily studied. Among various methods to analyze the status of the micro-algae including counting, screening, and flocculation, the flocculation approach has been widely accepted in many critical applications such as red tide removal study or microalgae resource study. To characterize the flocculation status of the micro-alga. A traditional optical modality, i.e., photospectrometry, measuring the optical density of the flocs has been frequently employed. While this traditional optical method needs shorter time than the counting method in flocculation status analysis, it has relatively lower detection accuracy. To address this issue, a novel real-time micro-algae flocculation analysis method based on the lens-free shadow imaging technique (LSIT) is introduced. Both single cell detection and floc detection are simultaneously available with a proposed lens-free shadow image, confirmed by comparing the results with optical microscope images. And three shadow parameters, e.g., number of flocs, effective area of flocs, and maximum size of floc, enabling quantification of the flocculation phenomenon of micro-alga, are firstly demonstrated in this article. The efficacy of each shadow parameter is verified with the real-time flocculation monitoring experiments using custom developed cohesive agents.

• Bulletin of Food Technology
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• v.8 no.3
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• pp.159-166
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• 1995