• Applied Biological Chemistry
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• v.11
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• pp.29-33
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• 1969

1. The oxidizability of $NADPH_2$ by quinones in the presence of $NADPH_2$-diaphorase was tested under aerobic conditions. Also the $^{14}CO_2$-fixation rates were compared when Chlorella suspensions were pretreated with $3{\cdot}10^{-5}M$ cocentration of variou quinones for 10 minutes prior and during the $^{14}CO_2$-fixation period. 2. A close correlation seems to exist between the rate of $NADPH_2$ oxidation by quinones and the $^{14}CO_2$-fixation rate. The effect of quinones on $NADPH_2$ oxidation and $^{14}CO_2$-fixation were in the order of Dichlone>06-K>NQ>BQ. 3. It is postulated that the phytotoxicity of quinones on Chlorella is due to the deprival of $NADPH_2$ consequently inhibiting $^{14}CO_2$-fixation, thus causing death of the cells. 4. The effect of quinones on amino acids biosyn-thesis in Chlorella was one of depressed rates, which was especially noted in the case of dichlone. This would be expected from a consideration of $NADPH_2$ deprival and inhibition of $^{14}CO_2$-fixation. Sucrose synthesis was either not affected or rather stimulated, the reasons of which are not clear at the present time.

• Journal of Environmental Science International
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• v.21 no.1
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• pp.89-96
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• 2012

The rate of photosynthesis (A) of leaves from 10 plant species (6 evergreen and 4 deciduous) of the family Fagaceae was measured using a portable photosynthesis analyzer, to examine which species take up $CO_2$ most efficiently. Of the evergreen species, the photosynthetic rate of Castanopsis cuspidata var. sieboldii was highest, and remained above 82.1~106.4 ${\mu}mol\;kg^{-1}s^{-1}$ from July to November. Of the deciduous species, the photosynthetic rate of Quercus acutissima was higher than that of the other three species, and remained high at 83.5~116.6 ${\mu}mol\;kg^{-1}s^{-1}$ from September to November. The photosynthetic rate of the 10 species was positively correlated with stomatal conductance (gs) and transpiration rate (E). However, there was no correlation between photosynthetic rate and intercellular $CO_2$ concentration ($C_i$), although there was a positive correlation just in three species (Q. gilva, Q. acutissima and Q. glauca). These results suggest that the $CO_2$ fixation capacity of C. cuspidata var. sieboldii, an evergreen species, and Q. acutissima, a deciduous species, is significantly higher than that of the other species examined, and that photosynthesis is regulated by both stomatal conductance and transpiration. Therefore, C. cuspidata var. sieboldii and Q. acutissima may be valuable for the evaluation of carbon uptake in urban green spaces as well as in afforested areas.

• Journal of Plant Biology
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• v.31 no.3
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• pp.197-203
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• 1988

The rates of photorespiration and total CO2 fixation depending on leaf ages of spinach (Spinacia oleracea L.) were investigated. Metabolic rates of glycolate and glyoxylate in isolated peroxisomes were also measured. The rate of photorespiration and total CO2 fixation ability increased with the maturing of leaf, but decreased with senescence. Activities of enzymes involved in the peroxisomal photorespiratory pathway such as catalase, glycolate oxidase, NADH-glyoxylate reductase and glutamate-glyoxylate transaminase were highest in the mature leaf, but also decreased with aging of leaf. Glutamate-glyxolate transaminase activity significantly decreased with senescence, especially. the metabolic rate of glycolate was observed to be lower than that of glyoxylate in isolated peroxisomes. Glycolate seemed to be metabolized mainly to glycine, however, it also oxidized to CO2 when glycolate was supplied as a substrate for glycine synthesis instead of glyoxylate. The conversion rates of glycolate and glyxylate into CO2 increased with the senescence of leaves.

• Journal of Wetlands Research
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• v.20 no.4
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• pp.363-369
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• 2018

One of the recent environmental problems is climate change due to the increase of atmospheric $CO_2$, which causes ecological changes and various environmental problems. Therefore, various studies are being carried out to reduce $CO_2$ in the world in order to solve various environmental problems caused by increase of $CO_2$. The $CO_2$ reduction using microalgae is an environmentally friendly method by using photosynthesis reaction of microalgae. However, most studies using single species. There is no study on the $CO_2$ fixing efficiency of microalgae in natural rivers. Therefore, this study was to identify the microalgae in the Sum river and to analyze the growth characteristics of microalgae in the river to obtain optimal culture conditions. And the changes of biomass and chlorophyll-a of microalgae were analyzed according to $CO_2$ concentration and injection rate. The purpose of this study was to investigate the fixing efficiency of carbon dioxide in microalgae in natural rivers. Six kinds of dominant species were observed as a result of the identification of microalgae in Sum river(Ankistrodesmus falcatus, Scenedesmus intermedius, Selenodictyum sp., Xanthidium apiculatum var. laeve, Cosmarium pseudoquinarium, Dictyosphaerium pulchellum). All of these species were green algae. Biomass and chlorophyll-a increased with the increase of $CO_2$ concentration and biomass and chlorophyll-a increased faster flow rate at the same $CO_2$ concentration. Also, the quantity of $CO_2$ fixation on the microalgae tended to be higher when the flow rate of injected gas was faster. This study can be referred as being significant in the micro-algae in river. In addition, the optimal conditions for $CO_2$ fixation of microalgae in rivers and the quantification of the quantity of $CO_2$ fixation from microalgae in rivers can be used as basic data for future policy of $CO_2$ reduction.

• Journal of Environmental Science International
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• v.25 no.8
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• pp.1143-1153
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• 2016

Plant biomass, photosystem II (PSII) photochemical activity, photosynthetic function, and zinc (Zn) accumulation were investigated in a sorghum-sudangrass hybrid (Sorghum bicolor ${\times}$ S. sudanense) exposed to various Zn concentrations to determine the elimination capacity of Zn from soils. Plant growth and biomass of the sorghum-sudangrass hybrid decreased with increasing Zn concentration. Symptoms of Zn toxicity, i.e., withering and discoloration of old leaves, were found at Zn concentrations over 800 ppm. PSII photochemical activity, as indicated by the values of $F_v/F_m$ and $F_v/F_o$, decreased significantly three days after exposure to Zn concentrations of 800 ppm or more. Photosynthetic $CO_2$ fixation rate (A) was high between Zn concentrations of 100-200 ppm ($22.5{\mu}mol$ $CO_2{\cdot}m^{-2}{\cdot}s^{-1}$), but it declined as Zn concentration increased. At Zn concentrations of 800 and 1600 ppm, A was 14.1 and $1.8{\mu}mol$ $CO_2{\cdot}m^{-2}{\cdot}s^{-1}$, respectively. The patterns of stomatal conductance ($g_s$), transpiration rate (E), and water use efficiency (WUE) were all similar to that of photosynthetic $CO_2$ fixation rate, except for dark respiration ($R_d$), which showed an opposite pattern. Zn was accumulated in both above- and below-ground parts of plants, but was more in the below-ground parts. Magnesium (Mg) and iron (Fe) concentrations were significantly low in the leaves of plants, and symptoms of Mg or Fe deficiency, such as a decrease in the SPAD value, were found when plants were treated with Zn concentrations above 800 ppm. These results suggest that the sorghum-sudangrass hybrid is able to accumulate Zn to high level in plant body and eliminate it with its rapid growth and high biomass yield.

• KSBB Journal
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• v.15 no.6
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• pp.644-648
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• 2000

Biological fixation of carbon dioxide using microalgae is known as an effective CO$_2$reduction technology. However, many environmental factors influence microalgal productivity. Optimal cultivation factors were determined for the green alga, Euglena gracilis Z, which offers high protein and vitamin E content for animal fodder. In batch culture in a photovioreactor, it was found that theinitial pH, temperature, CO$_2$concentration in air, and light intensity during the optimal cultivating conditions were 3.5, 27$^{\circ}C$, 5-10% and 520 ${\mu}$mol/㎡/s, respectively. When tap water and freshwater were used as cultivating media unsterilized tap water was found to be effective. A kinetic model was considered to determine the relationship between the specific growth rate and the light intensity. The half-velocity coefficient (K(sub)I) in the Monod model under photoautotrophic conditions was 978.9 ${\mu}$mol/㎡/s.

• Applied Biological Chemistry
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• v.40 no.2
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• pp.134-138
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• 1997

The objective of this study was to examine the effect of phosphorus deficiency on nitrogen fixation and photosynthesis of nitrogen fixing soybean plant under $CO_2$ enrichment condition. The soybean plants(Glycine max [L.] Merr.) inoculated with Bradyrhizobium japonicum MN 110 were grown with P-stressed(0.05 mM-P) and control(1 mM-P) treatment under control$(400\;{\mu}l/L\;CO_2)$ and enrichment$(800\;{\mu}l/L\;CO_2)$ enviromental condition in the phytotron equipped with high density lamp$(1000\;{\mu}Em^{-2}S^{-1})$ and $28/22^{\circ}C$ temperature cycle for 35 days after transplanting(DAT). At 35 DAT, phosphorus deficiency decreased total dry mass by 64% in $CO_2$ enrichment condition, and 51% in control $CO_2$ condition. Total leaf area was reduced significantly by phosphorus deficiency in control and enriched $CO_2$ condition but specific leaf weight was increased by P deficiency. Phosphorus deficiency significantly reduced photosynthetic rate(carbon exchange rate) and internal $CO_2$ concentration in leaf in both $CO_2$ treatments, but the degree of stress was more severe under $CO_2$ enrichment condition than under control $CO_2$ environmental condition. In phosphorus sufficient plants, $CO_2$ enrichment increased nodule fresh weight and total nitrogenase activity(acetylene reduction) of nodule by 30% and 41% respectively, but specific nitrogenase activity of nodule and nodule fresh weight was not affected by $CO_2$ enrichment in phosphorus deficient plant at 35 DAT. Total nitrogen concentrations in stem, root and nodule tissue were significantly higher in phosphorus sufficient plant grown under $CO_2$ enrichment, but nitrogen concentration in leaf was reduced by 30% under $CO_2$ enrichment. These results indicate that increasing $CO_2$ concentration does not affect plant growth under phosphorus deficient condition and phosphorus stress might inhibit carbohydrate utilization in whole plant and that $CO_2$ enrichment could not increase nodule formation and functioning under phosphorus deficient conditions and phosphorus has more important roles in nodule growth and functioning under $CO_2$ enrichment environments than under ambient condition.

• 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.

• Korean Journal of Environmental Biology
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• v.30 no.2
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• pp.98-106
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• 2012

The chlorophyll fluorescence and photosynthetic $CO_2$ fixation capacity of leaves from three major crop trees found on Jeju Island, Camellia sinensis L., Camellia japonica L., and Citrus unshiu M., were analyzed. The photosynthetic $CO_2$ fixation rate of C. sinensis was similar to that of C. unshiu, and much higher than that of C. japonica which belongs to the same genus. Stomatal conductance in the three species was high at dawn and low during daytime. The intercellular $CO_2$ concentration of the three species was also high at dawn and decreased at midday. The transpiration rate showed an opposite trend from the intercellular $CO_2$ concentration. The photochemical efficiencies of PSII (Fv/Fm) in C. sinensis were slightly lower at midday compared to the level at dawn and/or dusk. The decline in Fv/Fm of C. sinensis at midday was much smaller than that of C. japonica. These results indicate that C. sinensis is better acclimated to high levels of radiation under natural conditions in late summer, although its PSII reaction center was inhibited by strong radiation. Of the chlorophyll fluorescence parameters in the species, the RC/CS decreased significantly while the ABS/RC, TRo/RC, ETo/RC, and DIo/RC increased significantly at midday in late summer. However, C. unshiu did not show significant changes in these values depending on the time of day. Among the three species, the daily $CO_2$ fixation rate in C. sinensis ($320.1mmol\;m^{-2}d^{-1}$) was the highest, followed by that of C. unshiu ($292.5mmol\;m^{-2}d^{-1}$) and C. japonica ($244.8mmol\;m^{-2}d^{-1}$). Thus, C. sinensis may be a valuable crop tree in terms of the uptake of $CO_2$ under natural field conditions.

• KSBB Journal
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• v.26 no.6
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• pp.561-564
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• 2011

In this study, we carried out the development of high performance photobioreactor, which can be used to develop the biological $CO_2$ fixation technology as well as the renewable biofuels, the microalgae Botryococcus braunii. When B. Braunii was cultured in Anti-biofouling photobioreator, growth rate of it showed about 3 times higher than that of bubble column photobioreactor at the same conditions. In case of photobioreactor without bead, after 3 days culture time, biofouling occur rapidly in wall of the photobioreactor. However, with bead 5% (V/V), biofouling do not occur all experimental days.