• Journal of Microbiology and Biotechnology
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• v.24 no.9
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• pp.1189-1195
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• 2014

A strain-specific identification method is required to secure Chlorella strains with useful genetic traits, such as a fast growth rate or high lipid productivity, for application in biofuels, functional foods, and pharmaceuticals. Microsatellite markers based on simple sequence repeats can be a useful tool for this purpose. Therefore, this study developed five novel microsatellite markers (mChl-001, mChl-002, mChl-005, mChl-011, and mChl-012) using specific loci along the chloroplast genome of Chlorella vulgaris. The microsatellite markers were characterized based on their allelic diversities among nine strains of C. vulgaris with the same 18S rRNA sequence similarity. Each microsatellite marker exhibited 2~5 polymorphic allele types, and their combinations allowed discrimination between seven of the C. vulgaris strains. The two remaining strains were distinguished using one specific interspace region between the mChl-001 and mChl-005 loci, which was composed of about 27 single nucleotide polymorphisms, 13~15 specific sequence sites, and (T)n repeat sites. Thus, the polymorphic combination of the five microsatellite markers and one specific locus facilitated a clear distinction of C. vulgaris at the strain level, suggesting that the proposed microsatellite marker system can be useful for the accurate identification and classification of C. vulgaris.

• Food Science and Biotechnology
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• v.18 no.5
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• pp.1055-1062
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• 2009

This study was conducted to investigate whether dietary chlorella intake could have an effect on antioxidative capacity in rats oxidatively stressed with cadmium (Cd). Sprague-Dawley rats fed dietary chlorella (0, 5, and 10%) for 4 weeks after induction of oxidative stress by exposing to Cd (200 ppm) for 8 weeks. After the oxidative stress applied, plasma and liver malondialdehyde concentrations and xanthine oxidase activities were decreased in 5% chlorella fed group compared to chlorella free group. Although liver heme oxygenase-1 protein expression was not affected by chlorella, the enzyme activity was improved in 5% chlorella fed group. Erythrocyte superoxide dismutase activity and hepatic metallothionein concentration were increased in 5% chlorella fed group. However, 10% chlorella intake had no effect on the improvement of oxidative stress-related enzymes and proteins. These findings suggest that, after induction of oxidative stress with Cd, 5% chlorella intake might improve antioxidative capacity against oxidative stress.

• Applied Chemistry for Engineering
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• v.26 no.3
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• pp.265-269
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• 2015

Chlorella vulgaris (C. vulgaris) is a spherical unicellular green algae and the diameter ranges from 2 to $10{\mu}m$. C. vulgaris possess nutritional excellence because it contains various functional materials including high protein contents, chlorophyll, carotenoid, and chlorella growth factor (CGF). In order to study effects of mutagen, ethyl methane sulphonate (EMS) was used as a chemical mutagen and some mutants could be obtained. We named 2 type mutants as E14 and E24 obtained after treating with EMS. In the cell growth, growth patterns of mutants were similar to those of the wild type. Chlorophyll contents of E14 and E24 increased up to 99 and 52%, respectively compared to those of the wild type. The carotenoid content of E14 increased to 7%, but the value of E24 decreased 5% compared to that of the wild type. For the lipid contents E24 increased to 23%, while E14 decreased 12% when compared to those of the wild type. As a result, there is no difference between the mutants and wild type in the cell growth, but considering that mutants contains more physiological materials than those of the wild type, we can expect the mutants of C. vulgaris could be used as important high added-value materials.

• Journal of the Korean Society of Marine Environment & Safety
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• v.21 no.1
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• pp.1-8
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• 2015

We investigated the effect of monochromatic light emitting diode (LED) on the growth of diatoms Nitzschia sp., Phaeodactylum tricornutum, Skeletonema sp. and green algae Chlorella vulgaris. The four microalgae species were cultured under blue LED (450 nm), yellow LED (590 nm), red LED (650 nm) and fluorescent lamp (mixed wavelengths). The maximum growth rates and cell densities of Nitzschia sp., P. tricornutum and Skeletonema sp. were highest under blue LED, followed by fluorescent lamp, red LED and then yellow LED, however those of C. vulgaris were highest under red LED. This result indicates that blue LED is favorable for the growth of diatoms. Thus, the growth of microalgae under monochromatic light might be species-specific or taxon-specific. Also, these results could be used as an important information in future for remediation of heavy metal contamination in the sediments using LED and microalgae.

• Journal of Korean Society of Environmental Engineers
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• v.36 no.3
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• pp.214-220
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• 2014

The aim of this study is to optimize the efficiency of a photobiorector on the growth rate of Chlorella vulgaris (C. vulgaris) by varying distance of optical panel (OP). The round shaped C. vulgaris (FC-16) having the size of $3-8{\mu}m$ is employed in this study. The cells of C. vulgaris are cultured in the Jaworski's Medium with deionized water at $22^{\circ}C$ for 15 days. The OP is placed at four different distances i.e., at 225 mm distance (Run 1), 150 mm distance (Run 2), 112.5 mm distance (Run 3) and 90 mm distance (Run 4) having a LED (Light Emitting Diode) source. The diffuse rate is achieved to 86%, 90%, 92% and 94% for Run 1, Run 2 Run 3 and Run 4, respectively. A narrower distance of OP caused to effectively to increase the efficiency of diffuse light rate. For mass cultivation of this biomass, medium is changed according to distance of OP after attaining a maximum biomass concentration; Run 1 in 8 days, Run 2 in 6 days, Run 3 in 4 days and Run 4 in 3 days. In addition, the amount of maximum biomass rate for Run 4 was reached 3 times higher than that of Run1. However, growth rate, chlorophyll per cell, cell volume and doubling time are found to be Run 3 and Run 4 higher than that of Run 1 and Run 2 samples. However, Run 3 and Run 4 are having a slight difference in all these measurements. These findings suggest that in terms of economic consideration and efficiency towards simultaneous mass cultivation of biomass, Run 3 was found to be more effective than other samples.

• Applied Chemistry for Engineering
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• v.26 no.5
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• pp.533-537
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• 2015

Micro-algae Chlorella vulgaris (C. vulgaris) is an important source for bio-diesel because of the high content of neutral lipids. In this study, we intended to induce mutants of C. vulgaris by UV-B irradiation. C. vulgaris was first exposed to UV-B for 1, 2, 3, 4, 5 min. As the UV-B exposure time increased, the cell viability and pigment content were decreased. Mutants of C. vulgaris were also induced through ultraviolet irradiation and two strains were selected with respect to lipid contents, where were named as 'UM10', 'UM15'. They were then cultivated in the same way as to the wild type. After 21 days of cultivation, the cell growth, dry cell weight, pigment contents, and lipid contents were measured for investigating characteristics of mutants. As a result, the cell growth and dry cell weight of both mutants increased about 1.4 and 1.5 times, respectively compared with those of wild type. In addition, chlorophyll and carotenoid contents were measured in order to investigate pigment contents in micro-algae through photosynthesis. It was shown that chlorophyll and carotenoid contents of both mutants decreased about 10% compared to those of wild type. Lipid contents in UM10 and UM15 increased about 1.2 and 1.5 times, respectively compared to that of wild type.

• Journal of Korean Society of Water and Wastewater
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• v.31 no.5
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• pp.441-445
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• 2017

This study aimed to investigate growth rate and nutrient consumption of Chlorella vulgaris according to different light irradiation interval. Applied light irradiation intervals were 12 hr, 4 hr, 1 hr, and 1 min. The light source was flexible LED(Blue:Red=1:1), light intensity was 200 PPFD and Light/Dark cycle was 1:1. As a result, growth rate and nutrient removal efficiencies showed no significant differences depending on the light irradiation interval. Considering the reproduction characteristics of applied microalgae cultures of this study, this is thought to be one of the possible reasons of above results. Because Chlorella vulgaris performs an asexual reproduction and it is known that there is no significant relationship between light irradiation interval and growth rate, including nutrient consumption in case of asexual reproduction.

• Journal of the Korea Organic Resources Recycling Association
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• v.13 no.2
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• pp.91-97
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• 2005

The purpose of this research is malodor reduction of food waste leachate by some microorganism. In oder to observe the efficiency of malodor reduction by different microorganisms, 300ml of food waste leachate was fermented by the addition of 10% precultured seed microorganism such as marine algae of Spirulina plantensis, Chlorella vulgaris, the yeast Saccharomyces cerevisae and bacteria Bacillus cereus for 10 days. During the fermentation the change in pH, salinity and sensory evaluations were tested. As the results, the pH values of samples in the beginning were 3.5~4.0. After fermentation they are increased to the level 4.9~7.4. The salinity values of the samples fermented by Spirulina plantensis and Chlorella vulgaris were lowered rapidly. By the sensory evaluation, the efficiency of malodor reduction by Chlorella vulgaris of the marine microalgae showed almost inodorous degree of ordor 1.

• 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.