• Nutrition Research and Practice
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• v.3 no.2
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• pp.89-94
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• 2009

The aim of this study was to investigate if dietary Chlorella vulgaris(chlorella) intake would be effective on cadmium(Cd) detoxification in rats fed dietary Cd. Fourteen-week old male Sprague-Dawley(SD) rats weighing $415.0{\pm}1.6\;g$ were randomly divided into two groups and fed slightly modified American Institute of Nutrition-93 Growing(AIN-93G) diet without(n=10) or with(n=40) dietary Cd(200 ppm) for 8 weeks. To confirm alteration by dietary Cd intake, twenty rats fed AIN-93G diet without(n=10) and with(n=10) dietary Cd were sacrificed and compared. Other thirty rats were randomly blocked into three groups and fed slightly modified AIN-93G diets replacing 0 (n=10), 5 (n=10) or 10% (n=10) chlorella of total kg diet for 4 weeks. Daily food intake, body weight change, body weight gain/calorie intake, organ weight (liver, spleen, and kidney), perirenal fat pad and epididymal fat pad weights were measured. To examine Cd detoxification, urinary Cd excretion and metallothonein (MT) concentrations in kidney and intestine were measured. Food intake, calorie intake, body weight change, body weight gain/calorie intake, organ weight and fat pad weights were decreased by dietary Cd intake. Urinary Cd excretion and MT concentrations in kidney and small intestine were increased by dietary Cd. After given Cd containing diet, food intake, calorie intake, body weight change, body weight gain/calorie intake, organ weights and fat pad weights were not influenced by dietary chlorella intake. Renal MT synthesis tended to be higher in a dose-dependent manner, but not significantly. And chlorella intake did not significantly facilitate renal and intestinal MT synthesis and urinary Cd excretion. These findings suggest that, after stopping cadmium supply, chlorella supplementation, regardless of its percentage, might not improve cadmium detoxification from the body in growing rats.

• Journal of Korean Society on Water Environment
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• v.31 no.2
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• pp.134-141
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• 2015

The focus of this study was to observe the growth of Chlorella vulgaris and Botryococcus braunii under mixotrophic conditions (i.e., added acorn) with the aim of increasing biomass and triacylglycerols (TAGs) content. The result of investigation indicated that the acorn contains a lot of carbonate (87.29%) and glucose (97.99 mg%). A significant growth of biomass was obtained when grown in acorn rich environment comparing to autotrophic conditions. 3 g/L acorn yielded the highest biomass concentration for these strains. Thus, the biomass productivity with 3 g/L acorn was obtained 2.31 times and 2.10 times higher than that of authotrophic conditions for Chlorella vulgaris and Botryococcus braunii, respectively. The maximum amount of TAGs was reached 14.35% and 18.41% for Chlorella vulgaris and Botryococcus braunii, respectively, in the growth medium with 5 g/L acorn. The effect of acorn could enhance the investigated microalgae growth, biomass productivity and TAGs content. This provides a feasible way to reduce the cost of bioenergy production from microalgae.

• Journal of Korean Society of Environmental Engineers
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• v.34 no.7
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• pp.467-472
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• 2012

The aim of this study was to investigate the efficiency of optical panel (OP) on the growth rate of Chlorella vulgaris (C. vulgaris). The size of C. vulgaris (FC-16) was 3~$8{\mu}m$, having round in shape. The cells of C. vulgaris was cultured in the Jaworski's Medium with deionized water at $22^{\circ}C$ for 15 days. For this experiment, three light samples were prepared to evaluate the efficiency of OP on the growth rate of C. vulgaris; OP with LED (Light Emitting Diode) (Run 1), Fluorescent light (Run 2) and LED (Run 3). The specific growth rate of C. vulgaris for Run 1 was found to be 14 times and 5 times faster than Run 2 and Run 3, respectively. In addition, the average biomass of C. vulgaris for Run 1 was measured 11.79 g/L in 11 days. This means that the biomass for Run 1 was reached 30 times and 6.5 times higher than Run 2 and Run 3, respectively. This may be due to the fact the OP was increased the light uniformity and hindered the shading effects in photobioreactor. Therefore, the growth rate of biomass in photobioreactor with OP is compared better than the without OP used other photobioreactor.

• Applied Chemistry for Engineering
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• v.25 no.3
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• pp.324-329
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• 2014

Microalgae Nannochloropsis oculata (N. oculta) and Chlorella vulgaris (C. vulgaris) are important sources for biodisel because of the high content of neutral lipids. Stable nano bubble is maintained for a long time and therefore it is possible for use in biotechnology. In this study, effects of nano bubble oxygen or hydrogen water on the microalgae growth were characterized. The cell growth in nano bubble water was similar to that of control, and the total lipid content was rather low. But, chlorophyll content of N. oculata grown in nanno bubble oxygen and hydrogen water increased 54% and 30%, and increased 59%, 39% in C. vulgaris. Carotenoid content also increased 21%, 25% in N. oculata and 49%, 29% in C. vulgaris grown in nano bubble oxygen and hydrogen water. From these results, nano bubble water seems to enhance the photosynthetic capacity of microalgae.

• Microbiology and Biotechnology Letters
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• v.26 no.1
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• pp.76-82
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• 1998

The feasibility of algae as means of removing nitrogen and phosphorus from secondary treated swine wastewater was studied. Among the tested 7 species of Chlorella vulgaris (UTEX 265), Chlorella sp. GE 21, Botryococcus braunii (UTEX 572), Botryococcus sp. GE 24, Scenedesmus quadricauda, Phormidium sp. GE 2, and Spirulina maxima (UTEX 2342), C. vulgaris was selected for its fast growth and abilities to remove nitrogen and phosphorus and to produce algal biomass from swine wastewater. C. vulgaris grew well at 35$^{\circ}C$, and the optimum initial pH for growth was 8.0. In the effect of light intensity, the growth of C. vulgaris was limited under a light intensity of less than 40 ${\mu}$E/$m^2$/s. The secondary treated swine wastewater contained 58.7 mg/l of total nitrogen and 14.7 mg/l of total phosphorus, and was diluted to 75, 50, and 25% with groundwater to be treated. Nitrogen and phosphorus were removed by C. vulgaris in all diluted swine wastewaters among which the most effective removal was in 75% swine wastewater (swine wastewater:groundwater=3:1). There was a tendency of linear increase in nitrogen and phosphorus removal time with increasing concentration of swine wastewater. Under the optimized culture condition, total nitrogen and total phosphorus were effectively removed to 95.3% and 96.0%, respectively, in 25% swine wastewater after 4-day incubation.

• Journal of Environmental Science International
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• v.24 no.12
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• pp.1591-1600
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• 2015

The response of the freshwater microalga, Chlorella vulgaris, to heavy metal stress was examined based on chlorophyll fluorescence analysis to assess the toxic effects of heavy metals in freshwater ecosystems. When toxic effects were analyzed using regular chlorophyll fluorescence analysis, photosystem II activity($F_v/F_m$) decreased significantly when exposed to $Cu^{2+}$ and $Hg^{2+}$ for 12 h, and decreased in the order of $Hg^{2+}>Cu^{2+}>Cd^{2+}>Ni^{2+}$ when exposed for 24h. The effective photochemical quantum yield(${\phi}{\prime}_{PSII}$), chlorophyll fluorescence decrease ratio($R_{Fd}$), minimal fluorescence yield($F_o$), and non-photochemical quenching(NPQ), but not photochemical quenching(qP), responded sensitively to $Hg^{2+}$, $Cu^{2+}$, and $Cd^{2+}$. These results suggest that $F_v/F_m$, as well as ${\phi}{\prime}_{PSII}$, $R_{Fd}$, $F_o$, and NPQ could be used to assess the effects of heavy metal ions in freshwater ecosystems. However, because many types of heavy metal ions and toxic compounds co-occur under natural conditions, it is difficult to assess heavy metal toxicity in freshwater ecosystems. When Chlorella was exposed to heavy metal ions for 12 or 24h, $F_v/F_m$ and maximal fluorescence yield($F_m$) changed in response to $Hg^{2+}$ and $Cu^{2+}$ based on image analysis. However, assessing quantitatively the toxic effects of several heavy metal ions is challenging.

• Journal of Korean Society of Water and Wastewater
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• v.28 no.5
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• pp.573-579
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• 2014

VFAs like acetate are the major soluble metabolites of food waste leachates after digested. Therefore this study investigates the effect of acetate on growth rate and nutrient removal efficiency of Chlorella vulgaris to treat digested food waste leachates. The initial acetate concentration varied from 0 to 20 mM. As a result, Chlorella vulgaris growth rate was increased as high as the concentrations ranged from 0 to 20 mM. The same trend was observed with $NH_4$-N and $PO_4$-P consumption. The highest growth rate and the highest $NH_4$-N, $PO_4$-P removal rate were observed at acetate concentration of 20 mM. The microalgae growth rate and $NH_4$-N, $PO_4$-P removal rates were 1.5, 1.8, 2.3 times higher than the condition without acetate.

• Journal of Marine Bioscience and Biotechnology
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• v.16 no.1
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• pp.55-62
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• 2024

Various antimicrobial peptides (AMPs) from microalgae have shown antibacterial, antiviral, antifungal, anticancer, and antioxidant effects, and play crucial roles in medical applications, aquaculture-related disease management, and the food industry. Magainin 2 (MAG2), an AMP, exhibits high antibacterial and antitumor activity, necessitating an efficient recombinant expression system for low-cost, large-scale production. To enhance MAG2 secretion efficiency in Chlorella, we constructed the SS:MAG2:His vector using the known Chlamydomonas reinhardtii CA1 signal sequence (SS) and obtained a stable transformant via an Agrobacterium-mediated transformation method and RT-qPCR. ELISA results revealed that the MAG2 content secreted into the medium by the SS:MAG2:His transformants increased proportionally with mRNA expression. These findings offer a strategy for high MAG2 secretion in the Chlorella vulgaris platform, potentially minimizing downstream processing costs.

• Journal of Microbiology and Biotechnology
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• v.26 no.3
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• pp.503-510
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• 2016

The accumulation (internal and superficial distribution) of magnesium ions (Mg²⁺) by the green freshwater microalga Chlorella vulgaris (C. vulgaris) was investigated under autotrophic culture in a stirred photobioreactor. The concentrations of the three forms of Mg²⁺ (dissolved, extracellular, and intracellular) were determined with atomic absorption spectroscopy during the course of C. vulgaris growth. The proportions of adsorbed (extracellular) and absorbed (intracellular) Mg²⁺ were quantified. The concentration of the most important pigment in algal cells, chlorophyll a, increased over time in proportion to the increase in the biomass concentration, indicating a constant chlorophyll/biomass ratio during the linear growth phase. The mean-average rate of Mg²⁺ uptake by C. vulgaris grown in a culture medium starting with 16 mg/l of Mg²⁺ concentration was measured. A clear relationship between the biomass concentration and the proportion of the Mg²⁺ removal from the medium was observed. Of the total Mg²⁺ present in the culture medium, 18% was adsorbed on the cell wall and 51% was absorbed by the biomass by the end of the experiment (765 h). Overall, 69% of the initial Mg²⁺ were found to be removed from the medium. This study supported the kinetic model based on a reversible first-order reaction for Mg²⁺ bioaccumulation in C. vulgaris, which was consistent with the experimental data.

• Environmental Engineering Research
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• v.21 no.4
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• pp.401-408
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• 2016

The aim of this study was to evaluate the biomass and lipid production of Chlorella vulgaris and its nutrient removal capability for treatment of brewery wastewater effluent. The results indicate that the maximum biochemical oxygen demand (BOD) (91.43%) and chemical oxygen demand (COD) (83.11%) were removed by C. vulgaris with aeration in the absence of light. A maximum of 0.917 g/L of dry biomass was obtained with aeration in the dark conditions, which also demonstrated the highest amount of unsaturated fatty acids at 83.22%. However, the removal of total nitrogen (TN) and total phosphorus (TP) with these aeration and light conditions was 9.7% and 11.86% greater than that of other conditions. The removal of BOD and COD and the production of biomass and lipids with aeration in the dark and the TN and TP removal with aeration and light were more effective than other conditions in the brewery wastewater effluent in the presence of C. vulgaris.