• Korean Journal of Fisheries and Aquatic Sciences
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• v.40 no.3
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• pp.122-127
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• 2007

Photosensitized extracts of 28 seaweed species were tested in vitro to examine the variation in their algicidal activities against the toxic microalga Cochlodinium polykrikoides. When both seaweed extracts and microalgae were exposed to UV and visible light, methanol extracts of Porphyra yezoensis showed 5.7- and 4.4-fold increasesin light-dependent algicidal activity, respectively. When only seaweed extracts were exposed to both UV (365 nm) and visible light (white lamp) at the same time, methanol extracts of Enteromorpha linza and Carpopeltis affinis showed 3.3- and 3.4-fold increases in algicidal activity, respectively. When UV-photosensitized extracts were left in the dark, the algicidal activity of Ecklonia cava increased 13-fold after 5 h. When visible light-photosensitized extracts were left in the dark, the algicidal activity of Monostroma nitidum increased by 3.3-fold in 1 h.

• Journal of Life Science
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• v.28 no.3
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• pp.345-350
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• 2018

This study examines the role of six species of microalgae, including Phaeodacylum tricrnutum (PT), Chaetoceros gracilis (CG), Nanochloris oculata (NO), Pavlova lutheri (PL), Chlorella ellipsoidae (CE), and Scendedemus obliquus (SO), on hair loss prevention and scalp improvement. To determine the effects of microalgae extracts on hair loss prevention and scalp improvement, antioxidant activity, cell proliferation in HaCaT cells and HFDPC cells, and the inhibition level of 5-alpha reductase activity were examined. In the study of antioxidant activity, the $EC_{50}$ values of DPPH anti-radical activities indicated that the SO, CG, and ST9 treatment groups demonstrate significant antioxidant activity. In the study of the hydroxyl radical scavenging activity, CG (6.6~42.1%), ST9 (26.0~44.0%), and SO (7.8~44.3%) demonstrated significant effects. Furthermore, SO promoted the proliferation of HaCaT cells and a human epidermal cell line during a 6-day treatment. In the study of the proliferation of HFDPC cells, a hair follicle dermal papilla cell line, CG, and SO significantly stimulated cell proliferation. Finally, PT, CG, and SO significantly inhibited 5-alpha reductase activity. These results suggest that among the six microalgae used in this study, CG and SO have antioxidant effects, induce cell proliferation, inhibit 5-alpha reductase activity, and can be used for hair loss prevention and scalp improvement.

• Journal of Microbiology and Biotechnology
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• v.33 no.9
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• pp.1250-1256
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• 2023

Herein, different extracts of Scenedesmus deserticola JD052, a green microalga, were evaluated in vitro as a potential anti-aging bioagent. Although post-treatment of microalgal culture with either UV irradiation or high light illumination did not lead to a substantial difference in the effectiveness of microalgal extracts as a potential anti-UV agent, the results indicated the presence of a highly potent compound in ethyl acetate extract with more than 20% increase in the cellular viability of normal human dermal fibroblasts (nHDFs) compared with the negative control amended with DMSO. The subsequent fractionation of the ethyl acetate extract led to two bioactive fractions with high anti-UV property; one of the fractions was further separated down to a single compound. While electrospray ionization mass spectrometry (ESI-MS) and nuclear magnetic resonance (NMR) spectroscopy analysis identified this single compound as loliolide, its identification has been rarely reported in microalgae previously, prompting thorough systematic investigations into this novel compound for the nascent microalgal industry.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.5
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• pp.3312-3318
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• 2014

For the sunscreen development from natural resources, a possible usage of microalgal extracts or mycosporine-like amino acids (MAAs) was investigated. Sunscreens containing 7% of microalgal extracts or MAAs derived from microalgae, Chlamydomonas hedleyi, were prepared and they were applied to human research. Through this clinical research, the values of Sun Protection Factors, Sun Protector Factor (SPF) and Protection Factor of UVA (PFA), of sunscreen containing microalgal extracts or MAAs were determined: SPF values of microalgal extracts and MAAs indicated 9.07 and 9.42, respectively, while PFA ones did 2.43 and 2.41. Due to more than 2 of PFA value in both sunscreens, they can be classified into [PA+]. Taken together, although sunscreen containing microalgae-derived extracts or MAAs does not effectively protect UV irradiation, its capacity can be satisfied if inorganic UV-protecting compounds are added.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.6
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• pp.3799-3804
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• 2014

In sea water, microalgae are exposed to a range of critical environmental conditions. Microalgae are protected from UV-A radiation due to the presence of mycosporine like amino acids(MAAs). Owing to the UV-A absorption properties of MAAs, they are used widely as a UV protecting ingredient in cosmetics. Therefore, there is a need to increase the production yield of MAAs. This study investigated the production yield of MAAs in transformed microalgae by radiofrequency(RF) exposure. Initially, the Glut-1 gene was transformed to Chlamydomonas hedleyi microalgae as a glucose transporter. The biomass was enhanced after Glut-1 gene transformation. In addition, the MAAs production yield was increased during large scale production in bioreactors due to the RF treatment. Therefore, purified extracts of MAAs can be used as a sun block material in the cosmetic industrial field.

• ALGAE
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• v.19 no.3
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• pp.271-276
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• 2004

One hundred and fifty four micro algal strains, newly isolated from nationwide freshwaters in Korea, were screened for their anticancer, ant diabetic, and antibiotic activities. The micro algal strains were cultured with different nutritional conditions that were divided into 4 groups as follows; a normal Allen medium, nitrogen (N)-limited medium, phosphorus (P)-limited medium, and N and P-limited medium. Algal biomass was extracted with a mixture of acetone:H₂O (1:1, v:v) and the extracts were used for the screening of bioactive materials. Anticancer, ant diabetic, and antibiotic materials were screened by the methods of vaccinia Hl-related protein tyrosine phosphates (VHR DS-PTPase) inhibition, protein tyrosine phosphates 1B (PTP1B) inhibition, and paper disk. The inhibition activity of VHR DS-PTPase was observed in 18 strains, having a maximum 79% inhibition from Anabaena affinis and the inhibition activity of PTP1B was observed in 9 strains, having a maximum 97% from Sphaerocystis schroeteri. Microcystis aeruginosa incubated in an N and P-limited medium showed antibiotic activity in 8 species out of 13 pathogenic bacteria. As a whole, it seemed that the stressed condition such as N and/or P limitation increased the production of bioactive materials in micro algae.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.50 no.6
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• pp.738-744
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• 2017

Effect of dietary inclusion of microalgae, diatom-dominant, oil extracts (MOE) on growth, body composition and shell color of juvenile abalone Haliotis discus was investigated. One thousand four hundred and seventy juvenile abalone were distributed into 21 plastic rectangular containers. Seven experimental diets were prepared: MOE0, MOE0.01, MOE0.05, MOE0.1, MOE0.5, MOE1 and MOE2 diets containing MOE at the concentrations of 0, 0.01, 0.05, 0.1, 0.5, 1 and 2% at the expense of mixture of squid liver and soybean oils, respectively. The experimental diets were fed to abalone in triplicate once a day with a little leftover for 16 weeks. Weight gain and specific growth rate of abalone fed the MOE1 and MOE2 diets were higher than those of abalone fed the all other diets. The shell length and soft body weight of abalone fed the MOE2 diet were longer and heavier than those of abalone fed the all other diets. Crude protein and ash content of the soft body of abalone were affected by dietary inclusion of MOE. The shell color of abalone fed the all experimental diets was different from that of wild abalone. In conclusion, dietary inclusion of MOE improved growth of abalone, but did not shell color of abalone.

• Journal of Life Science
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• v.14 no.4
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• pp.589-592
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• 2004

The growth response of the fish-killing dinoflagellate Cochlodinium polykrikoides was studied in cultures, using the treatment of Ceratium extracts by a methanol, a water-soluble, and a cell-free medium. The cell-free medium had the most increasing on the growth of C. polykrikoides cultures, enriched with $\geq$ 25% Ceratium, whereas the methanol and water-souble fractions did not affect the growth of C. polykrikoides exposed to even higher concentration. In particular, the cell-free medium also increased the growth of Gyrodinium impudicum and Chaetoceros sp., similar species to C. polykrikoides. In contrast to C. polykrikoides, G. impudicum and Chaetoceros sp., the growth of Alexandrium tamarense was inhibited significantly, and there was no great effect on the growth of Prorocentrum minimum. These results imply that Ceratium extracts may play an important role in the stimulatory effect of C. polykrikoides, and they have to affect the interaction between C. polykrikoides and Ceratium when co-existing.

• ALGAE
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• v.34 no.2
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• pp.177-185
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• 2019

Ecklonia cava is popular in Korea as a marine functional materials. E. cava is generally collected and used on the coast of Jeju Island. However, the continuous use of collected natural E. cava may be limited because difficult to secure throughout the year and may be exposed to environmental pollution. Jeju magma seawater (MSW) was known to be significant advantages such as safety, cleanness, stability, and functional improvement. Attempts have been reported on application of MSW to the culturing of macro- and microalgae and showed improved results. Thus, the objective of the present study was to explore the anti-melanogenesis activity of brown seaweed E. cava (E. cava cultured with MSW [MSWE]) extract cultured in tanks with MSW of Jeju Island to evaluate the possibility of cosmeceutical industrial application. MSWE extract showed the higher polyphenolic and dieckol contents than natural E. cava (NE) extract. Anti-melanogenesis activity of MSWE extract and NE extract are tested and compared using tyrosinase and dihydroxyphenylalanine (DOPA) oxidation inhibition assay. MSWE extracts evidenced more effective tyrosinase and DOPA oxidation inhibition activity than that of the NE extracts and the commercial whitening agent, arbutin. MSWE extracts also markedly inhibited melanin synthesis and decreased the expression of melanogenesis-related protein in ${\alpha}$-melanocyte stimulating hormone-stimulated B16F10 melanoma cells without cytotoxicity. These results suggest that MSW cultivation process would be more effective in releasing bioactive compounds with whitening effect from seaweed such as E. cava at an industrial scale.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.34 no.3
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• pp.260-267
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• 2001

The biochemical composition and antioxidative activity of marine microalgae were investigated for the effective utilization of marine resources. Two species of marine microalgae, Nannochloris oculata (N. oculata) of Chlorophyceae and Phaeodactylum tricornutum (P. tricornutum) of Bacillariophyceae, were selected. Because these species showed the high growth rate and easy to continuous culture. The contents of crude protein, lipid, and carbohydrate were $54.91\%,\;11.29\%,\;and\;10.15\%$, for N. oculata and $38.07\%,\;13.19\%,\;and\;7.13\%$, for P. tricornutum, respectively. Glutamic acid was the highest concentration for both species. Galactose (3,712.02 mg/100g), fucose (1,966.03 mg/100g), and glucose (1,814.35 mg/100g) were the major carbohydrates for N. oculatae, and glucose (5,295.45 mg/100g) and mannose (841.34 mg/100g) were for P. tricornutum. K (12,906.86 mg/100g), Mg (1,039.15 mg/100g), Ca (882.57 mg/100g) and Fe (747.20 mg/100g) were the major minerals for N. oculata, and K (11,718.65 mg/100g), Ca (2,003.32 mg/100g), Mg (1,570.84 mg/100g) and Fe (552.58 mg/100g) were for P. tricornutum. In the composition of nucleotides, ADP ($4.77{\mu}mol/g$) was the highest in N. oculata and hypoxanthine (11.74{\mu}mol/g) in P. tricornutum. Large amount of linoleic acid (18: 2, $\omega-6$) was contained in N. oculata. In contrast 16: 1 ($\omega-7$) and 20: 5 ($\omega-3$) were major fatty acid in P. tricornutum. The antioxidative activities of organic solvent extracts of two microalgae were measured by the 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay method. The chloroform extract obtained from P. tricornutum was identified to be the most effective in DPPH radical scavenging activity.