• Journal of Marine Bioscience and Biotechnology
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• v.10 no.2
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• pp.91-96
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• 2018

There are many eutrophic lakes by point and non-point pollution sources such as in dustrial waste water, domestic raw sewage, and mucks. The eutrophic lakes not only cause algal blooms but also destroy the ecosystem in the lakes due to high nutrient concentrations. The purpose of this study was to improve water quality in eutrophic lakes by cultivating microalgae using photobioreactors (PBRs) with selectively permeable mesh (SPM), supplying nutrients in the lake and inhibiting cell leakage by diffusion and water permeability. Chlorella vulgaris, was cultivated using PBRs with SPM installed in Inkyung Lake located in Inha university, Incheon, Korea. When cultivating C. vulgaris, $8.3g/m^2/day$ of average biomass productivity was obtained at 3 days. Furthermore, concentrations of total nitrogen and phosphorus were reduced by 35.7% and 84.2%, respectively, compared to initial condition and water quality in eutrophic lake was improved to oligotrophic environment. These results suggest that microalgal cultivation using PBRs with SPM in the lake could produce microalgal biomass as well as improve water quality by decreasing nutrient concentrations.

• The Korean Journal of Pesticide Science
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• v.12 no.1
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• pp.50-56
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• 2008

The purpose of the study was to determine the effects of isoprothiolane, diazinon, butachlor, dimethametryn and molinate in Selenastrum capriconurtum, Scenedesmus subspicatus, Chlorella vufgaris and Nitzschia palea during an exposure period of 72 hours. The study was carried out in according with the OECD Guidelines for Testing of Chemicals No 201 Alga, Growth Inhibition Test. The toxicological responses of isoprothiolane to S. capriconutum, S. subspicatus, C. vulgaris and N. palea expressed as in individual $ErC_{50}$ (Median Effective Concentration by growth rate) value, were 5.87, 9.91, $18.55 and 38.79\;mg\;L^{-1}$, respectively. Diazinone to S. capriconutum, S. subspicatus, C. vulgaris and palea expressed as in individual $ErC_{50}$ value, were 10.31, 11.44, >32 and $14.32\;mg\;L^{-1}$, respectively. Butachlor to S. capriconutum, S. subspicatus, C. vulgaris and N. plaea expressed as in individual $ErC_{50}$ value, were 0.002, 0.019, 8.67 and $4.94\;mg\;L^{-1}$, respectively. Dimethamelryn to S. subspicatus, C. vulgaris and N. palea expressed as in individual $ErC_{50}$ value, were 0.0071, 0.011, 0.0065 and $0.009\;mg\;L^{-1}$, respectively. Molinate to S. capriconutum, S. subspicatus, C. vulgaris and N. palea expressed as in individual $ErC_{50}$ value, were 0.44, 1.26, 48.84 and $28.52\;mg\;L^{-1}$, respectively. The sensitivities of five pesticides were different depending on freshwater alga in the order of S. capriconutum > S. subspicatus > C. vulgaris, N. palea. Highly significant correlation (r=0.9677) based on $ErC_{50}$ were found between S. capriconutum and S. subspicatus.

• Food Science and Biotechnology
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• v.17 no.5
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• pp.953-958
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• 2008

The object of this study was to investigate the immune-enhancing effects of Chlorella vulgaris (CV) on a deteriorated immune function by a protein-energy malnutrition (PEM) diet. Unicellular algae, CV were used as a biological response modifier. Male C57BL/6J mice were fed for 15 days with standard diet or a PEM diet, which is associated with decreased host immune defense. After 8 days, mice in the PEM diet group were orally administered by 0.05, 0.1, and 0.15 g/kg body weight of CV or distilled water. Nutritional parameters, and interferon (IFN)-$\gamma$ levels were significantly increased in the blood serum of the CV (0.15 g/kg)-treated group (29.6$\pm$2.8 pg/mL) compared to the non-treated PEM group (4.1$\pm$0.4 pg/mL, p<0.05). In addition, cell proliferation and production of cytokines were investigated via a CV (0.01, 0.1, and 1 mg/mL) treatment using a human T cell line MOLT-4 cell. The CV treatment (1 mg/mL) significantly increased the production of both IFN-$\gamma$ and interleukin (IL)-2 (51.3$\pm$3.4 and 285.9$\pm$18.8 pg/mL, respectively) compared to the control (51.3$\pm$3.4 and 442.6$\pm$14.3 pg/mL, respectively), but did not affect the production of IL-4. These results suggest that CV may be useful in improving the immune function.

• Environmental Engineering Research
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• v.21 no.4
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• pp.393-400
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• 2016

The aim of this study was to evaluate the biomass production and dairy wastewater treatment using Chlorella vulgaris. The results indicated that the maximum percentages of biochemical oxygen demand, chemical oxygen demand, suspended solids, total nitrogen, and total phosphorus removed were 85.61%, 80.62%, 29.10%, 85.47%, and 65.96%, respectively, in dairy effluent at 10 d. A maximum of 1.23 g/L dry biomass was obtained in 7 d. The biomass productivity was strongly influenced by the nutrient reduction in the dairy effluent. The biodiesel produced by the C. vulgaris in the dairy effluent was in good agreement with the American Society of Testing and Materials-D6751 and European Standards 14214 standards. Therefore, using dairy effluent for microalgal cultures could be a useful and practical strategy for an advanced, environmentally friendly treatment process.

• Journal of Korean Society on Water Environment
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• v.31 no.6
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• pp.625-631
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• 2015

In this study, low cost bio-flocculants, chitosan, cationic starch and Mg-sericite, were used as a flocculant to harvest freshwater microalgae, Chlorella vulgaris. Chitosan, cationic starch and Mg-sericite separated successfully >98% of C. vulgaris at following optimal parameters: 90 mg/L chitosan at pH 6-7, 70 mg/L cationic starch at pH 9-10 and 50 mg/L Mg-sericite at pH 4-5. A relatively high correlation coefficient (R²) of 0.9993 for chitosan, 0.9971 for catonic starch and 0.9924 for Mg-sericite was obtained. The investigated flocculants amount increased linearly with increasing the microalgae amount. The biopolymer, Mg-sericite, was more effective than that of other investigated flocculants. These results indicated that a bio-flocculants, chitosan, cationic starch and Mg-sericite, could prove to be an effective flocculant for economical production of microalgae biomass. In addition, Mg-sericite was more effective comparing to the other investigated flocculants.

• Journal of Korean Society on Water Environment
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• v.31 no.3
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• pp.328-333
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• 2015

In this study, Mg-Sericite was used as a flocculant to harvest freshwater microalgae, Chlorella. vulgaris. Mg-Sericite separated successfully >95% of the C. vulgaris at the following optimal parameters: Mg/Si mol ratio 1.25 to 1.50, mixing time of 20 min and settling time of 20 min. The harvesting efficiency was pH dependent. The highest harvesting efficiency ($99{\pm}0.3%$) was obtained at Mg/Si mol ratio 1.5 and pH 9 to 11. These results indicated that a biopolymer, Mg-Sericite, can be a promising flocculant due to its high efficiency, low dose requirements, short mixing and settling times. This harvesting method is helpful to lower the production cost of algae for biodiesel.

• Clean Technology
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• v.23 no.1
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• pp.27-33
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• 2017

In this study, toxicities of seven metals (Cu, Cd, Cr, As(III), As(V), Zn, Ni) and five metal oxide nanoparticles (NPs: CuO, ZnO, NiO, $TiO_2$, $Fe_2O_3$) were evaluated based on the growth of Chlorella vulgaris. Effect on algae growth was evaluated by integrating the results of absorption, chlorophyll content, and cell count. The toxicity rankings of metals was observed as Cr ($0.7mgL^{-1}$) > Cu ($1.7mgL^{-1}$) > Cd ($3.2mgL^{-1}$) > Zn ($3.9mgL^{-1}$) > Ni ($13.2mgL^{-1}$) > As(III) ($17.8mgL^{-1}$) ${\gg}$ As(V) (> $1000mgL^{-1}$). Slightly different orders and sensitivities of metal toxicity were examined depending on endpoints of algal growth. In case of NPs, regardless of endpoints, similar toxicity rankings of NPs ($TEC_{50}$) were observed, showing ZnO ($2.4mgL^{-1}$) > NiO ($21.1mgL^{-1}$) > CuO ($36.6mgL^{-1}$) > $TiO_2$ ($62.5mgL^{-1}$) > $Fe_2O_3$ ($82.7mgL^{-1}$). These results indicate that an integrating results of endpoints might be an effective strategy for the assessment of contaminants.

• KSBB Journal
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• v.14 no.4
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• pp.414-421
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• 1999

The influenced of light intensity, cell density, and light pathlength on photosynthetic activity of Chlorella vulgaris were investigated. Since the light respon curve varied according to reaction conditions, the parameters estimated from nonlinear regression were proved to be apparent and could not be applied to various situations. The light response model incorporating the light penetration through the microalgal suspension was developed based upon the spatial distribution of the photosynthetic activity. This model showed a good agreement with experimental data at different cell densities and light intensities. Using the model the effects of cell density and light pathlenth were simulated and some dicussions about optimization of operation conditions of photobioreactors were carried out. Concludingly, the developed model can be useful for predicting microalgal photosynthesis and for determining the optimal operating conditions.

• Microbiology and Biotechnology Letters
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• v.40 no.3
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• pp.282-285
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• 2012

In this study, the ability of Chlorella vulgaris and Dunaliella salina to use biomass resources for anaerobic digestive biogas production was examined. The differences in cell wall structure pretreatments affecting the yield of soluble products showed that D. salina is a better candidate for biogas production than C. vulgaris. There was no significant difference between pretreated and non-pretreated D. salina in terms of methane production yield by inocula obtained from anaerobic digestion systems. Therefore, D. salina is a suitable algal biomass for biogas production due to its high biomass productivity, simple pretreatment needs, and easy conversion to biogas.

• Korean Journal of Ecology and Environment
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• v.36 no.2 s.103
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• pp.117-123
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• 2003

The results of field experiments with mesocosms on Lake Baikal, containing natural plankton assemblage, and laboratory experiments with microcosms containing Daphnia magna and Chlorella vulgaris demonstrated decrease of the structural exergy of the communities after the addition of allochtonous compounds peptone, diesel oil, o-diphenol, $CdCl_2$ to mesocosmsassemblage, phenol, $CoCl_2$ and $CuSO_4$ to micro-cosms. Structural exergy changes were more expressed than changes of components biomasses and total biomass of the community. Comparison of exergy content for benthos in cleanand affected by the discharges of Baikalsk Pulp and Paper Combine also showed sufficient docrease of structural exergy in polluted area. It points to the possibility of the use of structural exergy as ecosystem health reflecting parameter.