• Korean Journal of Microbiology
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• v.19 no.1
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• pp.8-13
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• 1981

The content of sulfhydryl compounds in Chlorella cells during the life cycle in the synchronous culture is determined spectrophotomatically at 250nm(pH7.0) using p-CMB as SH-reagent. The changes in the content of-SHl compounds and protein in Chlorella cells is measured during the life cycle in connection with cell division and analyzed. 1) The amounts of total ninhydrin reactive substance increased with growth of cells but increased the more at the $L_4$ stage(cytokinesis stage) than at the $L_2$ stage (nuclear division stage). 2) The sulfhydryl content of Chlorella cells increased strikingly at the $L_2$ stage and decreased markedly at the $L_4$ stage. 3) The amounts of values -SH/protein showed a peak at the $L_2$ stage. The increase of the amount of total-SH compounds of cells during the nuclear division period was considered to be caused by the weighty roles of protein-SH groups for the formation of nuclear division apparatus and for the enzyme activity.

• Molecular & Cellular Toxicology
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• v.4 no.2
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• pp.138-143
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• 2008

We investigated if Chlorella vulgaris (CV) has protective effects on cadmium (Cd) induced liver damage in male Sprague-Dawley (SD) rats. Forty rats, aged 5 weeks old and weighed 90-110g, were divided into a control (with Cd free water), 50 ppm of $CdCl_2$ in drinking water treated groups (Chlorella 0% diet group (Cd/CV0%), Chlorella 5% diet group (Cd/CV5%) or Chlorella 10% diet group (Cd/CV10%). All the rats had freely access to water and diet for 8 weeks. The results show that body weight gain and relative liver weight had significantly lower in Cd/CV0%-treated group than in Cd/CV-treated groups. Hepatic Cd contents showed significantly less by feeding CV (P<0.05). Cd/CV0%-treated rats had significantly (P<0.05) higher hepatic T-MTs, and Cd-MTs concentrations, compared to Cd/CV5% or Cd/CV10% treated rats. The MT I/II mRNA was expressed in the liver of all experimental rats. Its expression was more increased in Cd/CV5%- or Cd/CV10%-treated rats, compared to control and Cd-treated rats. Thus, this study suggested that CV would have a protective effect on Cd-treated liver injury by the reduction of Cd concentrations and stimulation of Cd-MT binds in the liver. However, more studies are needed to identify the proper mechanism of CV and liver toxicity.

• Journal of Marine Bioscience and Biotechnology
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• v.10 no.1
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• pp.18-25
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• 2018

Chlorella is quantitatively and qualitatively high in protein with balanced essential amino acid profiles, vitamins and minerals. ${\gamma}-Aminobutyric$ acid (GABA) is broadly distributed in nature and fulfills multi-physiological functions including effect such as a health-promoting functional compound. To improve the GABA production, Chlorella protothecoides were grown through the modified mixtrophic culture medium containing 2L of sterilized bristol medium with 0.01% urea and 4.0% glucose in a 5L fermenter. The results showed that nineteen kinds of amino acid including GABA at C. protothecoides sample were analyzed using high performance liquid chromatography (HPLC). Glutamic acid in total concentration (%) of amino acid is the most abundant amino acid (33.10%), followed by alanine (20.48%) and GABA (17.48%). Three amino acids including GABA were responsible for more than 70% total concentration in C. protothecoides sample including eight essential and nine non-essential amino acids: aspartic acid, asparagine, serine, glutamine, histidine, glycine, threonine, arginine, tyrosine, valine, methionine, tryptophan, phenylalanine, isoleucine, leucine, lysine. As a result of this experiment, it is expected that Chlorella will be developed to a critical product having high value as, GABA, functional food materials.

• Biomedical Science Letters
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• v.9 no.1
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• pp.15-19
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• 2003

Parathyroid hormone has clearly emerged as the most promising new anabolic treatment for osteoporosis by increasing the activation of osteoblast. It is known that chlorella increases both bone mineral density (BMD) and the rate of bone formation. The purpose of the present study was to determine whether the chlorella dietary supplementation could effect the thyroid or parathyroid hormones associated with increased BMD and bone formation. Twenty-two postmenopausal woman were treated for four month with 4 gm of chlorella dietary supplementation per day, then assessed serum calcium,25 OH vitamin D$_3$, thyroid hormone and parathyroid hormone before and after treatment. The mean 25 OH vitamin D$_3$ and parathyroid hormone were shown to marked increases by 193% and 265% respectively, in contrast to decreases by 9.4%, 37%, 33% and 14% in serum calcium, triiodo-thyroxine, free thyroxine and thyroxine stimulation hormone. In conclusion, treatment of postmenopausal women with chlorella dietary supplementation resulted in an increase in BMD and bone formation through enhancement of parathyroid hormone and 25 OH vitamin D$_3$, and a decrease in thyroid hormones.

• Journal of The Korean Society of Agricultural Engineers
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• v.52 no.6
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• pp.19-26
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• 2010

Batch experiments were conducted to investigate growth and nutrient removal performance of microalgae Chlorella vulgaris by using piggery wastewater in different concentration of pollutants and the common growth models (logistic, Gompertz and Richards) were applied to compare microalgal growth parameters. Removal of nitrogen (N) and phosphorus (P) by Chlorella vulgaris showed correlation with biomass increase, implying nutrient uptake coupled with microalgae growth. The higher the levels of suspended solids (SS), COD and ammonia nitrogen were in the wastewater, the worse growth of Chlorella vulgaris was observed, showing the occurrence of growth inhibition in higher concentration of those pollutants. The growth parameters were estimated by non-linear regression of three growth curves for comparative analyses. Determination of growth parameters were more accurate with population as a variable than the logarithm of population in terms of R square. Richards model represented better fit comparing with logistic and Gompertz model. However, Richards model showed some complexity and sensitivity in calculation. In the cases tested, both logistic and Gompertz equation were proper to describe the growth of microalgae on piggery wastewater as well as easy to application.

• Journal of Marine Bioscience and Biotechnology
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• v.10 no.2
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• pp.44-52
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• 2018

A synthetic pathway, which consisted of fatty acid double bond hydratase, alcohol dehydrogenase, and Baeyer-Villiger monooxygenase, was applied to Chlorella oil to produce ester fatty acids, which can be hydrolyzed into medium chain fatty acids. Since linoleic acid is a major fatty acid constituent of Chlorella oil, a fatty acid double bond hydratase from Lactobacillus acidophilus NBRC13951, which is able to convert linoleic acid into 13-hydroxyoctadec-9-enoic acid, was used. Recombinant Escherichia coli expressing the fatty acid double bond hydratase from L. acidophilus NBRC13951 successfully transformed linoleic acid in Chlorella oil hydrolysates into 13-hydroxyoctadec-9-enoic acid with approximately 60% conversion yield. 13-Hydroxyoctadec-9-enoic acid was further converted into ester fatty acids by the recombinant E. coli expressing a long chain secondary alcohol dehydrogenase and a Baeyer-Villiger monooxygenase. The resulting ester fatty acids were then hydrolyzed into medium chain fatty acids by a lipase. Overall, industrially relevant medium chain fatty acids were produced from Chlorella oil hydrolysates. Thereby, this study may contribute to biosynthesis of medium chain fatty acids from microalgae oils as well as long chain fatty acids.

• Journal of Microbiology and Biotechnology
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• v.32 no.11
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• pp.1357-1372
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• 2022

Heavy reliance on fossil fuels has been associated with increased climate disasters. As an alternative, microalgae have been proposed as an effective agent for biomass production. Several advantages of microalgae include faster growth, usage of non-arable land, recovery of nutrients from wastewater, efficient CO₂ capture, and high amount of biomolecules that are valuable for humans. Microalgae Chlorella spp. are a large group of eukaryotic, photosynthetic, unicellular microorganisms with high adaptability to environmental variations. Over the past decades, Chlorella has been used for the large-scale production of biomass. In addition, Chlorella has been actively used in various food industries for improving human health because of its antioxidant, antidiabetic, and immunomodulatory functions. However, the major restrictions in microalgal biofuel technology are the cost-consuming cultivation, processing, and lipid extraction processes. Therefore, various trials have been performed to enhance the biomass productivity and the lipid contents of Chlorella cells. This study provides a comprehensive review of lipid enhancement strategies mainly published in the last five years and aimed at regulating carbon sources, nutrients, stresses, and expression of exogenous genes to improve biomass production and lipid synthesis.

• Korean Journal of Organic Agriculture
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• v.26 no.3
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• pp.393-408
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• 2018

This study was carried out to investigate how chlorella dry powder added to the feed of laying hens influences on the egg quality and the composition of egg yolk's fatty acid. Moisture content, ash content, crude protein content, and crude fat content were 12.8%, 10.8%, 18.0% and 2.5%, respectively. The moisture content of the chlorella powder added to the feed was about 1.54%, the ash content was 6.53%, the crude protein content was 54.56%, and the crude fat content was 2.45 %. After feeding chlorella, compared to the control, the color of egg shell significantly became darker. The hardness of egg shell was increased for 10 days after chlorella feeding and was significantly strengthened. Thickness of egg shell was significantly thicker. The height of egg whites was increased. After 10 days of providing chlorella, the quality of egg white was 92.0 HU (Haugh Unit), which was significantly higher than 84.8 HU, the quality of the control. The color of egg yolk significantly revealed more yellow than that of the control. Egg weight was increased by 7.5% after 15 days of feeding chlorella. Protein content was increased by 11.9% and 10.7% after 10 and 15 days of feeding, respectively. The major compositions of fatty acid content of egg yolk fed with chlorella diet were oleic acid, trans-linoleic acid, palmitic acid, ${\alpha}$-linolenic acid, stearic acid, DHA, EPA, palmitoleic acid, and heptadecanoic acid, respectively. Palmitoleic acid was decreased in the eggs fed with chlorella diet compared to the control. The Saturated Fatty Acid (SFA) content of the control was higher than that of the eggs fed with chlorella. The content of Unsaturated Fatty Acid (UFA) was higher in egg yolks fed with chlorella than in the control. The ratio of UFA to Saturated Fatty Acid (SFA) was higher in egg yolks fed with chlorella than in the control. These results suggest that the addition of chlorella to the feed of the laying hens brings positive effects on the improvement of egg quality and lowering of the Unsaturated Fatty Acid of egg yolk.

• Journal of the Korea Organic Resources Recycling Association
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• v.6 no.1
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• pp.75-85
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• 1998

Algal meal (cell) was produced from the solution of dairy cow wastes by fermentation of ulothrix. sp. and chlorella sp. Raw wastes mainly feces were diluted with ground water to give dry matter concentration of 0.5 w/v of wastes in 20 l amounts of ten plastic containers. Each containers were covered with plastic nets and vinyl films to protect from the insects and rain. Algea cells were harvested every 3 to 5 days and dried by sunlight and artifitial heat. Dried cells were ground by a feed meal, and analyzed and tested for the chemical composition of dry cell, in vitro DM and protein digestibility and the safty of algae. Protein contents in algae meals, ulothrix (29.37%) and chlorella (29.24%) were similar. However, chlorella contained lower Neutral detergent fiber (5.92%) than ulothrix(20,76%), and higher ash (32.86%) and calcium (12.62%) than ulothrix (28.66% and 6.09%) (P<.01). Ulothrix protein had higher for essential amino acids; valine, isoleucine and phenylalanine, than chlorella (P<.05). Algal fats contained high saturated fatty acids, C16:0 and C18:0, for ulothrix and high unsaturated fatty acids, C18:1 and C18:2, for chlorella (P<.01). In vitro digestibility of. ulothrix tended to be higher for DM, but lower for protein than chlorella. The weight gain and survival percentage were higher for pond fishes (loaches, Misgurnus sp. ) fed diet added chlorella meal than diets added ulothrix meal and control diet (P<.05).