• Journal of Plant Biology
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• v.12 no.2
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• pp.7-14
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• 1969

Dunaliella tertiolecta did not show any increase in respiration rate when supplied with glucose, glycerol, sucrose, L-alanine, acetate, pyruvate and succinate. This was in contrast to Chlorella pyrenoidosa, which, under identical conditions, showed significant increase when supplied with glucose or acetate but not with the other compounds. Production of 14CO2 from added 14C-glucose in D. tertiolecta was lower than the other 14C-labelled substrates: L-alinine, glycerol, succinate, but higher than 14C-sucrose addition. And it was also lower than C. pyrenoidosa experiments which was added 14C-glucose as a substrate. Light reduced amounts of labelled carbon dioxide from 14C-glucose or 14C-acetate and increased incorporation of 14C from the substrates to cell materials in either D. tertiolecta or C. pyrenoidosa. The contribution of 14C from 14C-glucose to 14CO2 in cell-free system of D. tertiolecta were much higher than in whole cell suspension. It was contrast to C. pyrenoidosa which were showed reduction of 14CO2 production in cell-free systems than whole cell suspensions. When cell-free systems of D. tertiolecta and C. pyrenoidosa were supplied with ATP, NAD, NADP or/and hexokinase, it was remarkably increased production of 14CO2 from the substrates than the control. It was concluded that the low ability of D. tertiolecta to metabolize glucose were caused by the impermeability of the cell membrane to glucose and were not due to deficiencies of enzyme systems concerning glucose metabolism. In the cell-free systems, it seemed to be more active pentose phosphate pathway than glycolytic pathway in D. tertiolecta.

• Korean Journal of Microbiology
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• v.45 no.4
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• pp.385-390
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• 2009

To investigate the cellular growth traits of a photosynthetic green algae, Chlorella pyrenoidosa, several tests upon a culture temperature, a culture time, the influence of nutrient and the intensity of illumination were executed. Using growth chamber, some optimal conditions for the culture of algae were as follows: The culture temperature was about $28^{\circ}C$, the culture time about 4 days, and the cellular growth of algae was in proportioned to the concentration of nutrient such as nutrient broth. And the more the intensity of illumination was increased, the more the algal cell showed good growth. And then, the activity of enzyme degrading acetaldehyde was also studied using HPLC from the same strain. This enzyme was dependent on $\beta$-$NAD^+$. And showed its optimal pH around on 9.0, and also its optimal temperature around at $40^{\circ}C$. The operational conditions of HPLC were as follows: Column, ODS-Hypersil ; mobile phase, 50% (v/v) acetonitrile.

• Journal of Plant Biology
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• v.12 no.2
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• pp.15-22
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• 1969

By spectrophotometric assay method, the following enzymes could be detected in Dunaliella tertiolecta and Chlorella pyrenoidosa cell-free extracts: Hexokinase; Glucose-6-phosphate, 6-Phosphogluconate and Triosephosphate dehydrogenase; Transketolase; Phosphogluco and Ribosephosphate isomerase; Phosphoglucomutase; Phosphofructokinase; Fructosediphosphate aldorase and Ribulosephosphate 3-epimerase. Such enzymes are in accordance with the proposed pathway of glucose catabolism by D. tertiolecta as well as C. pyrenoidosa. Also, it could be estimated, under the presence of NADP, that pentose phosphate pathway were more active than glycolytic pathway in D. tertiolecta cell-free systems.

• Microbiology and Biotechnology Letters
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• v.17 no.2
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• pp.170-172
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• 1989

It is preyed that marine algae, Chlorella pyrenoidosa can synthesize about 3.52% of eicosapentaenoic (EPA) of dry cell weight at the light intensity of 10 W/$\m^2$ which is optimal light intensity of producing EPA at $25^{\circ}C$. An equation to predict the amounts of EPA in the culture broth is derived as an exponential form with 0.91 of the correlation factor. The behavior of cell growth follows a photo-inhibition model by showing 12 W/$\m^2$ of saturation light intensity.

• Bulletin of the Korean Chemical Society
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• v.24 no.12
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• pp.1763-1766
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• 2003

Algal growth studies of Chlorella strains were conducted in a batch mode with bench type experiments. Carbon dioxide fixation rates of the following green microalgae were determined: Chlorella sp. H84, Chlorella sp. A2, Chlorella sorokiniana UTEX 1230, Chlorella vulgaris, and Chlorella pyrenoidosa. C. vulgaris, among other strains of microalgae, showed the highest growth rate (1.17 optical density/5 days). Cultivating conditions for C. vulgaris that produced the highest growth rate were at concentrations of 243 ${\mu}g\;CO_2$/mL, 10 mM ammonia, and 1 mM phosphate, with an initial pH range of 7-8.

• Journal of Ecology and Environment
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• v.37 no.4
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• pp.315-325
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• 2014

Aerial algae were sampled from 28 sites on rocks, tree barks, and mosses along the Hongcheon-river in Gangwon-do, Korea, from December 2011 to September 2012 and then cultivated. Seven genera and eight species of the order Chlorococcales were newly recorded in Korea. These were Spongiococcum tetrasporum, Tetracystis aggregata, Myrmecia bisecta, Coenocystis inconstans, Lobosphaeropsis pyrenoidosa, Pseudococcomyxa simplex, Coelastrella oocystiformis, and C. vacuolata. As a result, the known Korean flora of the order Chlorococcales now includes 12 families with 54 genera, 263 species, 76 varieties, and 27 forma, giving a total of 366 taxa.

• Korean Journal of Organic Agriculture
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• v.22 no.4
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• pp.743-760
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• 2014

This study aimed to isolate and identify freshwater algae from the organic agricultural ecosystems and investigate its biological characteristics to study the possibility of utilizing a biomass freshwater algae in organic farming. In the survey area, average water temperature was $12.4{\sim}28.2^{\circ}C$ and the pH ranges were from 6.1 to 8.5. The solid culture method is more suitable than liquid culture method for isolation of freshwater algae with lower contamination level and higher isolation frequency. A total of 115 strains were isolated from six freshwater algae habitats in nine regions in Korea. BGMM (BG11 Modified Medium) amended with NaNO3 and $KNO_3$ as a nitrogen, and $Na_2CO_3$ as carbon source was designed to isolate and culture freshwater algae. Absorbance of freshwater algae culture has increased dramatically to four days and decreased after eight days after inoculation. CHK008 of the seven isolates showed the highest absorbance in seven days after culturing in BGMM. The optimal pH of BGMM for culturing freshwater algae was pH 6-7. As light intensity increased, growth of freshwater algae increased. Among the five kinds of carbon sources, glucose and galactose promoted good growth of freshwater algae in BGMM. The colony color of purified 16 green algae isolates showed a separation of green, dark and light green, and of them, eleven algae strains showed a strong fluorescent light under fluorescence microscopy. Cell size of the green algae showed a wide range of variation depending on the species. General morphology of the green algae strains was spherical. Chlamydomonas sp. was elliptical, and Chlorella sorokiniana was ellipsoidal and cylindrical. All strains of the green algae except for Chlamydomonas sp. did not have flagella. One isolate of Chlamydomonas sp. and five isolates of C. sorokiniana secreted mucus. Sixteen isolates of 16 green algae were identified as two family and six species, Chlorella vulgalis, C. sorokiniana, C. pyrenoidosa, C. kessleri, C. emersonii, and Chlamydomonas sp. based on their morphological characteristics.

• Journal of Plant Biology
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• v.17 no.2
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• pp.69-83
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• 1974

To elucidate the relationship between chemical structure and biological activity of alantolactone, and also to investigate the relationship between the growth of cells and the respiration of Chlorella pyrenoidosa affected by alantolactone, alantolactone and isoalantolactone were isolated from Inula helenium L., and di-, and tetrahydroalantolactones were prepared by the hydrogenation. At a concentration of 5$\times$10-5M alantolactone, the growth rate of Chlorella was greatly reduced. The viability of cells was also reduced over 50% within 2 hr at a concentration of 2.5$\times$10-4M alantolactone. However, oxygen uptake was increased by 20% over 3 hr. And 14CO2 production from glucose-1-14C, glucose-6-14C and 14C-acetate-U.L. was also increased by alantolactone. Biological activityof alantolactone was significantly reduced by cysteine, reduced glutathione or cystine but not by tryptophan or histidine. It was detected by spectrophotometrically and by TLC that alantolactone was also reacted with thiols except cystine. The solution of alantolactone reached with thiol gave the UV absorption spectrum of $\alpha$-saturated ${\gamma}$-lactone, and most of SH groups were disappeared by the addition reaction. From the reaction mixture of alantolactone and cysteine, a lactone adduct was isolated and purified. Isoalantolactone had shown similar activity as alantolactone, however, it was appeared that di-, and tetrahydroalantolactones were not only inactive biologically but also in vitro. It was concluded that there was no correlationship between increased respiration rate and mortality of Chlorella. During the respiration TCA cycle was activated, however it was uncertain that the activation of EMP or HMP was also appeared. Alantolactone and isoalantolactone were biologically active compounds but others were inactive. The reactivity of $\alpha$-methylene ${\gamma}$-lactone moiety toward SH group was principally responsible for its biological activity in sesquiterpene lactones.