• Journal of the Korean Society for Marine Environment & Energy
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• v.19 no.3
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• pp.236-245
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• 2016

Because microalgae represent high growth rate than terrestrial plants, and it can accumulate significant lipid and carbohydrate content, and other bioactive compounds such as carotenoid and polyphenol in their body, it has been considered as one of the promising resources in bio-energy, and other industries. Although many studies has been performed about the microalgae-derived biochemical accumulation under various abiotic conditions such as different temperatures, salinities and light intensities, the studies about simultaneous effect of those parameters has rarely been performed. Therefore, this study focused on evaluation of simultaneous effect of different salinity (10, 30, 50 psu) and temperatures (20, 25, $30^{\circ}C$) on the changes of biomass, lipid, starch and photosynthetic pigment accumulation. As results, the highest growth rate was achieved at $30^{\circ}C$ and 30 psu in the both algal cultures, and the photosynthetic pigment, chlorophyll a and total carotenoid content, were increased in a temperature-dependent manner. The accumulation of lipid and starch contents exhibited different aspects under different combinations of temperature and salinity. From the results, it is suggested that the changes of microalgal lipid and starch accumulation under different salinities may be affected by the different temperatures.

• ALGAE
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• v.31 no.3
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• pp.277-287
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• 2016

Five fractions separated from Nannochloropsis oculata using solvent-solvent partition chromatography of 80% methanolic extract of N. oculata (NOM) followed by the open silica column chromatography of its hexane fraction (NOMH) for the anti-inflammatory on RAW 264.7 cells and anti-cancer activities on HL-60, A-549, HEP-3B, HCT-116, and SW-480 cancer cells. All the five fractions showed potential anti-inflammatory activities against lipopolysaccharide-stimulated RAW 264.7 macrophages cells with IC₅₀ values less than 6.25 μg mL⁻¹. Moreover, 90% n-hexane column elution of NOMH (NOMH90) down-regulated lipopolysaccharide-stimulated protein levels of inducible nitric oxide synthase and cyclooxygenase-2. Furthermore, NOMH90 showed marked cytotoxic effect on the HL-60 cells with IC₅₀ value of 23.58 ± 0.09 μg mL⁻¹. In addition, Hoechst 33342 cell permeable dye used to visualize the apoptosis nucleus and cell cycle analysis measured Sub-G1 DNA contents to confirm reduction of the cell viability in NOMH90 treated cells due to induction of apoptosis in HL60. These results are quite related to the phytosterol contents of the NOMH fractions and the results suggest N. oculata extracts might be useful as potential sources of natural anti-inflammatory and anti-cancer compounds. In conclusion, the sterol content in N. oculata might provide a promising role in future medicines in anti-inflammatory and anti-cancer.

• Journal of Aquaculture
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• v.11 no.1
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• pp.91-97
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• 1998

This paper introduces to a simple culture method and growth of axenic (bacteria-free) rotifer Brachionus rotundiformis for seed stock of rotifer mass culture. This rotifer axenic culture method is based on the washing and transferring with sterilized sea water and modified antibiotic mixture AM9 solution. Population growth (final density on day 16) of axenic cultured rotifer were maintained with a high density and stable growth compared with the control of non-axenic culture (general culture style) through the 3 times-rerunning experiments (trial 1, 2 and 3). But the egg carrying rates of amictic females were not different between the axenic-and non-axenic culture condition. Although, rotifer density was higher in axenic culture, the food (Nannochloropsis oculata) was still remained unutilized than that of the non-axenic culture in third trial culture. These results suggest the possible existence of harmful bacteria for the rotifer population growth in the trial 1 and 3 of non-axenic culture compared to the trial 2. This axenic rotifer culture method is valuable for seed stock of the stable rotifer mass cultures.

• Korean Journal of Environment and Ecology
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• v.29 no.4
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• pp.564-569
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• 2015

In order to discover materials that can be used for OLED, extractions of marine microalgae was screened for photoluminescence(PL) properties and analyzed using gas chromatography-mass spectrometry(GC-MS). The extractions of Nitzschia denticula, Navicula cancellata and Nannochloropsis salina showed PL spectroscopy among fourteen marine microalgae species. The selected three fractions from three microalgae were analyzed by GC-MS. According to the results, it was found that the identified organic light-emitting materials can be subdivided into three functional groups based on imidazole, purine and quinoline. These chemicals are considered to have a strong relationship with PL spectroscopy for OLED materials.

• Fisheries and Aquatic Sciences
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• v.20 no.10
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• pp.24.1-24.8
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• 2017

The experiment was conducted to investigate the effects of different algae in diet on growth, survival, and interleukin-10 productions of sea cucumber. At first, a 9-week feeding trail was conducted to evaluate the growth performance and survival of the sea cucumber fed one of the six experimental diets containing ST (Sargassum thunbergii), UL (Ulva lactuca), UP (Undaria pinnatifida), LJ (Laminaria japonica), SS (Schizochytrium sp.), and NO (Nannochloropsis oculata) in a recirculating aquaculture system. The result showed that survival was not significantly different among the dietary treatments, and the specific growth rate (SGR) of sea cucumber fed the UL diet ($1.58%d^{-1}$) was significantly higher than that of sea cucumber fed the other diets (P < 0.05), except for the LJ and NO diets. Secondly, interleukin (IL)-10 gene expression was determined where mice splenocytes were stimulated with $10{\mu}g\;ml^{-1}$ of sea cucumber extracts for 2 h. The result showed that IL-10 gene expression levels were significantly increased in UL, LJ, and NO diets fed sea cucumber extracts compared to other experimental diets. The results suggest that dietary inclusion with Ulva lactuca, Laminaria japonica, and Nannochloropsis oculata algae may improve the growth of juvenile sea cucumber and could upregulate IL-10 gene expression in mice splenocytes. Such detailed information could be helpful in further development of more appropriate diets for sea cucumber culture.

• Microbiology and Biotechnology Letters
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• v.47 no.1
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• pp.11-19
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• 2019

The properties of microalgae as bioresources for biodiesel production can be improved by adding nitrogen sources into the culture medium. Thus, Nannochloropsis oceanica CCAP 849/10 was cultured in f/2 media supplemented with five different forms of nitrogen at $0.88mmol-N\;l^{-1}$ each: ammonium bicarbonate ($NH_4HCO_3$), ammonium sulfate ($(NH_4)_2SO_4$), sodium nitrate ($NaNO_3$), ammonium nitrate ($NH_4NO_3$), and urea. The cell density, lipid content, and fatty acid profile of the microalga were determined after 15 days of cultivation. The growth of N. oceanica based on cell number was lowest in the medium with $NH_4NO_3$, and increased significantly in the medium with $NH_4HCO_3$. Cells treated with $(NH_4)_2SO_4$, and $NH_4NO_3$ produced the highest total lipid contents (i.e., 65% and 62% by dry weight, respectively). The fatty acid profiles of the microalga were significantly different in the various nitrogen sources. The major fatty acids detected in cultures supplemented with $NH_4HCO_3$, $(NH_4)_2SO_4$, $NH_4NO_3$, or urea were C14:0, C16:0, C16:1, C18:0, C18:1, C18:2, C20:5, and C22:6. However, the C16:1 content in the $NaNO_3$-supplemented culture was very low. This study highlights that the nitrogen source can strongly influence lipid production in N. oceanica and its fatty acid composition.

• Proceedings of the IEEK Conference
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• 2000.07b
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• pp.789-792
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• 2000

Marine chlorella (Nannochloropsis oculata) is cultivated at the fish farming association of experimental fishery laboratory. In the culture of the chlorella, it is necessary to count the number of chlorella in order to understand the condition of increase. For that purpose, we develop automatic chlorella counter using the image processing and the neural network. Its effectiveness is confirmed through the experiment.

• Korean Journal of Environment and Ecology
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• v.30 no.1
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• pp.92-97
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• 2016

The purpose of this study was to improve growth and survival rate of marine microalgae and macroalga zoospores using with eco-friendly capsulation materials. The capsulation materials were chosen an alginic acid which extracted from marine brown algae combining with starch and calcium chloride. The capsulated microalgae, Nannochloropsis salina and macroalga zoospores, Ulva australis were evaluated with growth and survival rate. When the mixed ratio of alginic acid was less than 50%, capsule formation was not performed. When the ratio of 50% alginic acid and 50% starch, the microalgae was shown the highest growth and survival rate increasing up to $8.74{\times}10^5cells\;mL^{-1}$ while 100% of alginic acid was the lowest rate up to $4.92{\times}10^5cells\;mL^{-1}$. The increasing starch ratio improved to their growth and survival rate, however decreasing alginic acid make physical capsule formation weaken. By applying on a surface of artificial reef, capsulated algal zoospores were germinated 99 individuals $cm^{-2}$. This attempt will be provided to basic core technology for marine afforestation in coastal area.

• Journal of Aquaculture
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• v.18 no.1
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• pp.13-18
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• 2005

This study was to investigate the effects of water temperature and food on the mass seed production of larval parrot fish, Oplegnathus fasciatus. Growth of the larvae reared at heated water temperature ($25.3^{\circ}C$) was significantly higher than that of the larvae reared at natural water temperature ($20.5^{\circ}C$). In addition, survival rate of the larvae at heated and natural sea water temperature were $24.0\%$ and $12.3\%$, respectively (P<0.05). Growth and survival rate of the larvae fed mixed diets of Nannochloropsis oculata, rotifer (Brachionus rotundiformis). Artemia nauplii, Tigriopus japonicus and artificial diets were significantly higher than that of the larvae fed only either rotifer or artificial diets (P<0.05). The average survival rate and total length of the larvae reared for 50 days after hatching were $22.5\%$ and 62.0$\pm$4.0 mm, respectively. Amount of consumed rotifers at one time feeding by a larva was rapidly increased with growth from 10.3 individuals per larva 5 day old to 65.5 individuals per larva 20 day old.

• Journal of Aquaculture
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• v.13 no.1
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• pp.63-67
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• 2000

Tigriopus japonicus harpacticoida copepod was a common copepoda species as food organism for the marine fish larval rearing. However T. japonicus was difficult to stable culture except for a mixed culture with rotifer. Available food source for the successfully stable culture of T. japonicus was investigated in this study. T. japonicus did not utilization Nannochloropsis oculata instead of that. T japonicus utilized to products from rotifer culture tank. The products from rotifer culture tank was composed of rotifer feces and co-existing aquatic bacteria. The nauplius I stafe and copepodid I stage of T. japonicus showed grown whenproducts from rotifer culture tanks was fed. Specially we observed higher density of nauplii than that of copepodites and ovisac carrying females in the experimental culture populations.