• ALGAE
• /
• v.28 no.3
• /
• pp.281-288
• /
• 2013

Photosynthetic carbon fixation regulates air-sea $CO_2$ fluxes in the waters of coral reefs. However, little has been documented on the effects of solar UV radiation (UVR, 280-400 nm) upon photosynthetic behaviors of phytoplankton dwelling in these ecosystems. In order to evaluate the aforesaid, surface dwelling tropical coral reef phytoplankton assemblages collected from the South China Sea were exposed to solar radiation (i.e., photosynthetically active radiation [PAR] + UV radiation A [UVA] + UV radiation B [UVB], 280-700 nm; PAR + UVA, 320-700 nm; and PAR, 400-700 nm) under static or simulated-mixing conditions. Under the static condition, UVA and UVB significantly reduced the carbon fixation with the maximum of 22.4 and 15.3%, respectively; while lower UVR-related photosynthetic inhibition was observed in case of phytoplankton samples being subjected to mixing. At a moderate level of mixing (i.e., circulation time 80 min), the UVA and UVB caused inhibition were lowered by 52.1 and 79.6%, respectively. Based on this it could be stated that vertical mixing induced by winds and/or tides in the natural environments could reduce the inhibitory effect of solar UVR on phytoplankton productivity in the coral reefs water.

• Journal of Korean Society of Forest Science
• /
• v.86 no.1
• /
• pp.35-45
• /
• 1997

This study has been carried out to estimate carbon fixation, and carbon NPP based on equation form of $Wt=aD^bH^c$ in natural stand of Quercus mongolica and Quercus variabilis in Chungju. The effect of improvement of environment was also evaluated by estimating sink of $CO_2$ gas in forest ecosystem of Korea in a year. The following effects have been obtained in analysing estimate of allometric equation. Equation form of $Wt=aD^bH^c$ was the most adequate, those of $Wt=a(D^2H)^b$, $Wt=aD^b$ estimate of the biomass and the carbon fixation in Quercus natural stand of Chungju. Total above ground of Quercus mongolica was 130.58 t/ha and that of Quercus variabilis was 137.38 t/ha. Annual production of two stands was 9.96 t/ha/yr, 8.64 t/ha/yr, respectively. Carbon fixation of total above ground was 60.52t C/ha in Quercus mongolica stand, and was 62.22t C/ha in Quercus variabilis stand. Annual fixation of carbon was 4.78t C/ha/yr and 4.28t C/ha/yr, seperately. Annual emission of carbon estimated 2.44t C/ha/yr in contrast of forest area in Korea. It was showed that the annual fixation of carbon was higher 1.84t C/ha/yr~2.34t C/ha/yr than annual emission of carbon. But foliage was 2.39t C/ha/yr and 1.89t C/ha/yr, which occupied 40% and 50% of annual carbon fixation of total above ground. Annual carbon fixation may fluctuate about 1.89t C/ha/yr~2.39t C/ha/yr by seasons.

• Biotechnology and Bioprocess Engineering:BBE
• /
• v.11 no.6
• /
• pp.484-488
• /
• 2006

Alteration of illumination with optimum carbon dioxide fixation-based curve in this research successfully enhanced the $CO_{2}-fixation\;(q_CO_{2}$ capability of Chlorella vulgaris Buitenzorg cultivated in a bubble column photo bioreactor. The level of $CO_{2}$ fixation was up to 1.91 times that observed from cultivation with intensification of illumination on an optimum growth-based curve. During 144 h of cultivation, alteration of light intensity on an optimum $CO_{2}-fixation-based$ curve produced a $q_CO_{2}$ of $12.8\;h^{-1}$. Meanwhile, alteration of light intensity with a growth-based curve only produced a $q_CO_{2}$ of $6.68\;h^{-1}$. Increases in light intensity based on a curve of optimum $CO_{2}-fixation$ produced a final cell concentration of about 5.78 g/L. Both cultivation methods were carried out under ambient pressure at a temperature of $29^{\circ}C$ with a superficial gas velocity of $2.4\;m/h(U_{G}$. Cells were grown on Beneck medium in a 1.0 L Bubble Column Photo bioreactor illuminated by a Phillips Halogen Lamp (20 W/12 V/50 Hz). The inlet gas had a carbon dioxide content of 10%.

• Journal of Korean Society of Rural Planning
• /
• v.26 no.2
• /
• pp.61-70
• /
• 2020

The purpose of this study is to calculate the annual carbon reduction of crops according to the carbon fixation method of agricultural land, therefore to analyze whether the economic inducement of farmers to switch from single cropping to double cropping if the amount of carbon reduction were traded on the Korea Exchange. The analysis targets were Gyeonggi Province, which was divided into four areas to compare the difference between agricultural income and carbon income by crop and cropping system. Agricultural profit was estimated by multiplying the prior data of 2012 by the change rate of the consumer price index, and carbon income was calculated through the carbon reduction for each crop and the average transaction price of KAU19 traded on the Korea Exchange. According to the analysis, the profit rate of double cropping in all areas is -110.4% to 23% compared to single cropping, when only agricultural profit is taken into account, with no economic inducement for farmers to change the cropping system. However, when carbon income is taken into account together, the profit rate of double cropping rises significantly from 122.5% to 238.9% over a single operation in all areas, resulting in an economic inducement to switch the cropping system. This research is meaningful in that farming households could raise their income by additional carbon income, and that carbon credits could be supplied at Korea Exchange to further boost the carbon emission exchange.

• 한국생물공학회:학술대회논문집
• /
• 2001.11a
• /
• pp.181-184
• /
• 2001

The biological fixation of carbon dioxide using microalgae have many advantages over chemicals and remove carbon dioxide simultaneously. A ketocarotenoid astaxanthin is hyper-accumulated in the green freshwater microalga, Haematococcus pluvialis. In the present study, the combine effects of carbon dioxide concentration and light intensity on the growth of H. pluvilais were investigated. The carbon dioxide concentration above 10% caused a severe inhibition and around 5% is optimal for growth. Adaptation to high concentration of carbon dioxide enhanced the $CO_2$ tolerance. Specific growth rate calculated differently based upon cell number or dry weight because of the distinctive life cycle patterns of H. pluvialis : small-sized motile green cell and thick cell walled red cyst cell. Based on the light dependence of H. pluvialis, internally illuminated air-lift photobioreactor was designed and operated. Gradual increase of light supply gave more active growth and more effective productivity of astaxanthin than constant light supply.

• Proceedings of the Korea Society for Energy Engineering kosee Conference
• /
• 1995.05a
• /
• pp.82-87
• /
• 1995

Carbon dioxide fixation by microalgae has several advantages such as no requirements for the pretreatment over phycal and/or chemical $CO_2$ fixation processes. Chlorella sp. HA-1, fresh algae. and Chlorococcum littorale. marine algae, were used to do $CO_2$ fixation work. The experimental parameters were light intensity and $CO_2$ concentration. Chlorella sp. HA-1 has the maximum growth rate at 8 Klux and 10% $CO_2$ concentration. Chlorococcum littorale showed the maximum growth at similar conditions. The results indicated the feasibility of the Chlorella HA-1 and Chlorococcum littorale for mass cultivation using flue gas.

• Bulletin of the Korean Chemical Society
• /
• v.23 no.7
• /
• pp.1027-1028
• /
• 2002

• Journal of Plant Biology
• /
• v.31 no.4
• /
• pp.277-288
• /
• 1988

The effects of ammonium ion and glutamate on CO2 fixation abilities and related carbon metabolism were investigated in pea (Pisum sativum L. cv. Sparkle) leaf discs under conditions favoring photorespiration (21% O2, 0.03% CO2) and nonphotorespiration (5% O2, 0.03% CO2). A concentration of more than 10 mM of NH4+ decreased the photosynthetic CO2 fixation and those inhibitory effects were more remarkable in 21% O2 than in 5% O2 conditions. The effect of glutamate on CO2 fixation was found to be independent of the O2 level, as glutamate increased the CO2 fixation under both 21% and 5% O2 conditions. L-methionine-dl-sulfoximine, an irreversible inhibitor of glutamate synthetase, however, inhibited the CO2 fixation markedly under 21% O2, but did not affect it under 5% O2 conditions. The treatment with NH4+ elevated the relative amounts of 14C incorporated into soluble components from 14CO2 with no relation to O2 levels, while glutamate increased 14C into insoluble components and neutral sugars. Glutamate, especially, seemed to stmulate the biosynthesis of starch under 5% O2 condition. These results indicated that NH4+ stimulated the degradation of sugar or starch and this proposal was confirmed by the increasing of pyruvate kinase activity in leaf discs treated with ammonium ion.

• Environmental Engineering Research
• /
• v.12 no.4
• /
• pp.136-147
• /
• 2007

In an effort to identify possible microbes for seeking bioagents for remediation of herbicide-contaminated soils, seven species of phototrophic nonsulfur bacteria (Rhodobacter capsulatus and sphaeroides, Rhodospirillum rubrum, Rhodopseudomonas acidophila, blastica and viridis, Rhodomicrobium vannielii) were grown in the presence of the herbicide, butachlor, and bacterial growth rates and nitrogen fixation were measured with different carbon sources. Under general conditions, all species showed 17-53% reductions in growth rate following butachlor treatment. Under nitrogen-fixing conditions, Rb. capsulatus and Rs. rubrum showed 1-4% increases in the growth rates and 2-10% increases in nitrogen-fixing abilities, while the other 5 species showed decreases of 17-47% and 17-85%, respectively. The finding that Rp. acidophila, Rp. blastica, Rp. viridis and Rm. vannielii showed stronger inhibitions of nitrogenase activity seems to indicate that species in genera Rhodobacter and Rhodospirillum are less influenced by butachlor than those in Rhodopseudomonas and Rhodomicrobium in terms of nitrogen-fixing ability. Overall, nitrogenase activity was closely correlated with both growth rate and glutamine synthetase activity (representing nitrogen metabolism). When the carbon sources were compared, pyruvate (three carbons) was best for all species in terms of growth rate and nitrogen fixation, with malate (four carbons) showing intermediate values and ribose(five carbons) showing the lowest; these trends did not change in response to butachlor treatment. We verified that each of the 7 species had a plasmid ($12.2{\sim}23.5\;Kb$). We found that all 7 species could use butachlor as a sole carbon source and 3 species were controlled by plasmid-born genes, but it is doubtful whether plasmid-born genes were responsible to nitrogen fixation.

• KSBB Journal
• /
• v.13 no.1
• /
• pp.101-107
• /
• 1998

Carbon dioxide is estimated to be responsible for 60% of the global warming effect, and this percentage is tending upward. Studies on removal and fixation of $CO_2$ in the flue gas are recognized as one of the important roles of the future biotechnology. Photobiological systems have considerably higher photosynthetic efficiency than conventional biomass system. The experiment for the photosynthetic fixation of $CO_2$ and the biomass production was performed with various initial cell concentration in a tubular photobioreactor and a bubble column $CO_2$ contactor with a gas sparger of $CO_2$ -enriched air(0.03~20%). Synechocystis PCC 6803 could grow at 10~20% $CO_2$ content under pH control. The highest specific growth rate, 0.0258 $h^{-1}$ , was obtained at 5% $CO_2$-air mixture. The maximum cell production rate, 0.2784 g/L.day, was obtained when the initial cell concentration was 0.45 g/L at 5% $CO_2$ -air mixture. The maximum cell concentration was 2.03 g/L in the tubular photobioreactor when the light intensity was $45.5{\mu}$ $E/m^2$ . s. This system showed 0.482 g $CO_2$ /L . day of the $CO_2$ fixation.