• Journal of Microbiology and Biotechnology
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• 제30권6호
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• pp.868-877
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• 2020

Bicarbonate has been considered as a better approach for supplying CO₂ to microalgae cells microenvironments than gas bubbling owing to cost-effectiveness and easy operation. However, the β-carotene production was too low in Dunaliella salina cultivated with bicarbonate in previous studies. Also, the difference in photosynthetic efficiency between these two carbon sources (bicarbonate and CO₂) has seldom been discussed. In this study, the culture conditions, including NaHCO₃, Ca²⁺, Mg²⁺ and microelement concentrations, were optimized when bicarbonate was used as carbon source. Under optimized condition, a maximum biomass concentration of 0.71 g/l and corresponding β-carotene content of 4.76% were obtained, with β-carotene yield of 32.0 mg/l, much higher than previous studies with NaHCO₃. Finally, these optimized conditions with bicarbonate were compared with CO₂ bubbling by online monitoring. There was a notable difference in F_v/F_m value between cultivations with bicarbonate and CO₂, but there was no difference in the F_v/F_m periodic changing patterns. This indicates that the high concentration of NaHCO₃ used in this study served as a stress factor for β-carotene accumulation, although high productivity of biomass was still obtained.

• 마이크로전자및패키징학회지
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• 제27권4호
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• pp.11-17
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• 2020

Copper has been proved to be the best catalyst for electrochemical CO2 reduction reaction, however, for optimal efficiency and selectivity, its performance requires improvements. Electrochemical CO2 reduction reaction (RR) using CuO nanowire electrode was performed with different concentrations of KHCO3 electrolyte (0.1 M, 0.5 M, and 1 M). Cu(OH)2 was formed on Cu foil, followed by thermal-treatment at 200℃ under the air atmosphere for 2 hrs to transform it to the crystalline phase of CuO. We evaluated the effects of different KHCO3 electrolyte concentrations on electrochemical CO2 reduction reaction (RR) using the CuO nanowire electrode. At a constant current (5mA), low concentrated bicarbonate exhibited a more negative potential -0.77 V vs. Reversible Hydrogen Electrode (RHE) (briefly abbreviated as VRHE), while the negative potential reduced to -0.33 VRHE in the high concentration of bicarbonate solution. Production of H2 and CH4 increased with an increased concentration of electrolyte (KHCO3). CH4 production efficiency was high at low negative potential whereas HCOOH was not influenced by bicarbonate concentration. Our study provides insights into efficient, economically viable, and sustainable methods of mitigating the harmful environmental effects of CO2 emission.

• Reproductive and Developmental Biology
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• 제32권4호
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• pp.237-243
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• 2008

The objective of this study was to examine the effect of caffeine and sodium bicarbonate in a fertilization medium on the fertilizability of boar spermatozoa that were frozen in straws. Boar spermatozoa were extended with Beltsville F5 extender and frozen in 0.25-ml straws. In vitro matured porcine oocytes were fertilized in vitro (IVF) with frozen-thawed boar spermatozoa for 6h in a modified tris-buffered medium (mTBM) or in its modified medium by substituting the tris with 25mM sodium bicarbonate (modified bicarbonate-buffered medium; mBBM). Some of inseminated oocytes were fixed and stained for examination of sperm penetration. IVF embryos were cultured in a North Carolina State University-23 medium for embryo development. The percentage of live sperm was $47{\pm}4%$ and morphological abnormality of acrosome was found in $14{\pm}3%$ of spermatozoa. Optimal sperm concentration for IVF was $0.75{\sim}1.0{\times}1.0{\times}10^6$ sperms/ml when mTBM containing 5mM caffeine was used as the fertilization medium. Sperm penetration was significantly (p<0.05) stimulated by increasing caffeine concentration in the IVF medium. In addition, mBBM significantly (p<0.05) increased sperm penetration (92%) compared to mTBM (65%). More (p<0.05) blastocysts (22% vs. 32%) developed from the oocytes that were fertilized in mBBM containing 1mM caffeine than from those fertilized in mTBM with 5mM caffeine. Our results indicate that boar spermatozoa can be frozen successfully in straws with holding their normal fertilizability and that caffeine and sodium bicarbonate stimulates sperm penetration in vitro.

• 한국환경과학회지
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• 제13권3호
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• pp.279-288
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• 2004

This study aimed at improving the $TiO_2$ photocatalytic degradation of HA. A set of tests was first conducted in the dark to study the adsorption of HA at different coexisting material concentration. Adsorption rate increased with adding cation ion but decreased with adding bicarbonate ion. The photodegradation of HA in the presence of UV irradiation was investigated as a function of different experimental condition: initial concentration of HA, $TiO_2$ weight, pH, air flow rate and coexisting material. It was increased either at low pH or by adding cation ion. The increase of cation strength in aqueous solution could provide a favorable condition for adsorption of HA on the $TiO_2$ surface and therefore enhance the photodegradation rate. It was found that bicarbonate ions slowed down the degradation rate by scavening the hydroxyl radicals.

• Journal of Industrial and Engineering Chemistry
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• 제68권
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• pp.301-310
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• 2018

Various catalysts such as formic acid, acetic acid, sodium hydroxide, sodium bicarbonate, carbon dioxide and nitrogen gas were used for hydrolyzates production from deoiled mackerel muscle by subcritical water hydrolysis. Above 99% hydrolysis yield was obtained using sodium bicarbonate catalyst at $260^{\circ}C/70bar$. Histamine and heavy metals concentration were reduced in hydrolyzates. Highest amount of amino acid (400.36 mg/g) and reducing sugar (24.75 mg/g) were found in hydrolyzate obtained at $260^{\circ}C/70bar$ and $220^{\circ}C/30bar$, respectively with sodium bicarbonate catalyst. Antioxidant and ACE-inhibitory activities were significantly higher in hydrolyzates obtained using sodium bicarbonate than that of others.

• 대한지하수환경학회지
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• 제5권2호
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• pp.66-79
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• 1998

본 연구는 제주도 백록담 담수호에서 해안변 용천수에 이르는 고도별로 대표적인 55개 용천수에 대한 지역적 수질특성과 그 진화과정을 연구하였다. 조사지역 55개 용천수의 수질분석 결과 관음사물은 수소이온농도에서, 유수암천, 장수물, 덕지샘물, 신촌큰물, 영천사, 운량천, 하원통물, 동해물, 색달생수, 안덕계곡, 화순곤물, 돗물, 화강물, 정금물은 주변 육상오염원들에 의해서, 삼양제3수원, 신촌큰물, 명법사, 서느렁물, 토산물, 정금물, 곽지물, 애월하물, 고내물, 녹고물은 해수침입에 의해 오염이 진행중인 용천수들로 분류되었다. 용천수내의 전기전도도, pH, 질산성질소, 중탄산이온은 강수량이 많았을 때 그 농도가 증가하였으며, 나트륨, 염소이온, 황산이온은 강수량이 많았을 때 그 농도가 감소하였고, 칼륨과 마그네슘, 칼슘은 영향이 미미하였다. Piper의 삼각다이어그램을 통한 조사지역 용천수의 수질특성을 보면 고산지역은 Sodium or Potassium type과 bicarbonate type의 군을 이루었고, 중산간지 역은 Sodium or Potassium type과 No dominant type의 군을 형성하였으며, 저지대지역은 No dominant type과 Sulfate or Nitrate type의 군을, 해안지역은 Sodium or Potassium type과 Chloride type 및 No dominant type의 복잡한 용천수군을 형성하고 있었다. 즉 제주도 용천수는 해발고도가 높은 고산 및 중산간지역에서는 bicarbonate type이 우세한 수질조성에서 저지대 및 해안지역으로 유동되면서 non-bicarbonate type 형태의 수질로 변질되어가고 있었다.

• Journal of Microbiology
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• 제37권3호
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• pp.159-167
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• 1999

The effects of bicarbonate concentration, atmospheric carbon dioxide level, and reduced atmospheric oxygen on biomass and geosmin production and geosmin/biomass (G/B) values for Streptomyces halstedii, a producer of the off-flavor compound geosmin, were determined. In addition, a study was performed to determined possible synergistic relationships between a cyanobacterium, Oscillatoria tenuis UTEX #1566, and S. halstedii in the enhancement of actinomycete growth and/or geosmin production. These studies took into consideration those conditions that can occur during cyanobacterial bloom die-offs. Increasing bicarbonate concentration caused slight decreases in geosmin production and G/B for S. halstedii. Increasing atmospheric oxygen promoted geosmin production and G/B while lower oxygen levels resulted in a decrease in geosmin production and G/B by S. halstedii. Biomass production by S. halstedii was adversely affected by reduced oxygen levels while changes in bicarbonate concentration and atmospheric carbon dioxdie levels had little effect on biomass production. Sonicated cells of O. tenuis UTEX #1566 promoted biomass production by S. halstedii, and O. tenuis culture (cells and extracellular metabolites) and culture supernatnat (extracellular metabolites) each promoted geosmin and G/B yields for S. halstedii. In certain aquatic systems, environmental conditions resulting from cyanobacterial blooms and subsequent bloom die-offs could favor actinomycete growth and off-flavor compound by certain actinomycetes.

• Journal of Radiation Protection and Research
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• 제15권2호
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• pp.27-39
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• 1990

원자력산업의 시설증대로 우라늄 오염의 가능성이 증가되고 있음에도 불구하고 종사자 및 국민에 대한 안전대책 및 의료적 처치에 관한 연구가 매우 미흡한 실정에 있어 이에 대한 응급처치방안을 수립코자 우라늄을 투여한 후 제염제를 투여하여 관찰하였던 바 다음과 같은 결론을 얻었다. 1. 우라늄오염에 의한 체중변화에 미치는 제염제의 영향에 있어서 sodium bicarbonate와 생리적 식염수를 병행투여한 군과 우라늄을 투여하고 30분이 지나서 dithiothreitol을 투여한 군에서는 우라늄단독투여군에 비해 체중이 현저하게 증가하였다.(P<0.05). 2. 모든 실험군은 우라늄오염에 의한 음수량과 배뇨량의 변화를 유의성 있게 호전시켰으며(P<0.05), 특히 sodium bicarbonate와 생리적 식염수를 병행투여한 군과 우라늄을 투여하고 30분이 지나서 dithiothreitol의 투여한 군이 가장 높은 증가경향을 나타냈다(p<0.05). 3. 우라늄오염에 의한 BUN농도 변화에 미치는 제염제의 효과는 sodium bicarbonate와 생리적 식염수를 병행투여한 군과 우라늄을 투여하고 30분이 지나서 dithiothreitol를 투여한 군이 공히 우라늄단독투여군보다 BUN 농도가 매우 감소되었다(P<0.01). 4. 우라늄을 투여하고 30분이 지나서 dithiothreitol를 투여한 군은 우라늄오염에 의한 serum creatinine의 농도증가를 유의하게 감소시켰으나 (P<0.01), sodium bicarbonate와 생리적 식염수를 병행투여한 군은 다소 감소하는 경향으로 나타났다. 5. 우라늄오염에 의한 urine creatinine농도 변화에 미치는 제염제의 효과에 있어서 sodium bicarbonate와 생리적 식염수를 병행투여한 군과 우라늄을 투여하고 30분이 지나서 dithiothreitol를 투여한 군에서는 우라늄단독투여군에 비해 cretinine의 배설이 상당히 증가하였다(P<0.05). 6. 우라늄오염에 의한 신장의 소견에 있어 우라늄단독투여군은 근위곡세뇨관상피의 공포화 및 종창, microvilli와 brush border의 손실, 세뇨관 상피의 괴사가 관찰되었으며, 간장의 충혈, 중심성 괴사 및 모세관 확장증도 관찰되었다. 그리고 sodium bicarbonate와 생리적 식염수를 병행투여한 군과 우라늄을 투여하고 30분이 지나서 dithiothreitol를 투여한 군에서는 우라늄 단독투여군에 비해 높은 방호효과가 관찰되었으나 다른 실험군에서는 큰 효과가 없는 것으로 나타났다. 결론적으로 우라늄의 체내오염시에는 sodium bicarbonate와 생리적 식염수를 가능한 빨리 병행투여하거나 dithiothreitol을 체내오염후 30분이 지나서 투여하는 방법이 우라늄오염에 대한 제염에 매우 유효할 것으로 생각되며, 특히 우라늄에 의한 인체장해를 유의하게 경감시켜줄 것으로 사료되었다.

• Asian-Australasian Journal of Animal Sciences
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• 제21권12호
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• pp.1728-1735
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• 2008

The present study was conducted with four ruminally canulated Holstein cows to observe the effects of monensin or fish oil on diet fermentation and production of conjugated linoleic acids (CLAs) in the rumen when fed diets supplemented with soybean oil and sodium bicarbonate. Cows of the control treatment were fed a basal diet (CON) consisting of 60% commercial concentrate and 40% chopped rye grass hay. Cows of other treatments were fed the same diet as CON, but the concentrate was supplemented with 7% of soybean oil and 0.5% of sodium bicarbonate (SO-B), SO-B supplemented with monensin (30 ppm, SO-BM) or concentrate supplemented with 6.3% of soybean oil, 0.5% of sodium-bicarbonate, 30 ppm of monensin and 0.7% of fish oil (SO-BMF). Dry matter (DM) intake of the cows was significantly (p<0.011) reduced by feeding the SO-BMF diet compared to the other diets which did not differ in DM intake. Whole tract digestibility of major dietary components was significantly (p<0.004-0.027) higher for SO-BMF than the other supplement-containing diets. Dietary supplements did not clearly affect rumen pH and ammonia concentrations compared to the CON diet. Significantly reduced (p<0.05) total VFA concentration was obtained by the addition of fish oil to the diet (SO-BMF) compared to other diets. No differences, however, were obtained in major VFA proportions as well as in total VFA between the supplemented diets. The SO-BM diet increased (p<0.01-0.05) the concentrations of trans-11 $C_{18:1}$ and linoleic acid in rumen fluid. Total CLA concentration was also increased by the feeding of SO-B and SO-BM diets during early fermentation times (up to 3 h) post-feeding. Cis-9, trans-11 CLA concentration in rumen fluid was highest (p<0.05) for SO-B up to 1 h while the highest (p<0.01) value for SO-BM occurred at 3 h post-feeding. An increased trans-10, cis-12 CLA concentration was obtained from the SO-B and SO-BM diets at 1 and 3 h post feeding compared to the other diets. Supplementation of oils with monensin and sodium bicarbonate increased (p<0.05) the proportions of $C_{18:1}$ and CLA in the plasma of cows, but the effect of monensin and/or fish oil was limited to trans-10, cis-12 CLA.

• 상하수도학회지
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• 제18권2호
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• pp.174-180
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• 2004

This study is a fundamental research to test the applicability of abandoned eggshell as seed material for crystallization reaction. Eggshell was calcinated at $850^{\circ}C$ and ground to lesser than 0.42mm. The calcination characteristics of eggshell were examined by X-ray diffraction (XRD). The effect of initial calcium concentration, alkalinity, reaction temperature condition, seed dosage were studied by batch test. For the low concentration sample(P concentration is under 50mg/L), more than 90% of P can be removed. The effect of initial calcium concentration(0~120mg/L) was performed. At the result of the test, more than 50mg/L calcium concentration has high removal efficiency. Alkalinity effect was studied for synthetic solution(100mg/L initial P, 50mg/L calcium, 0.025% seed dosage) with 0~300mg/L bicarbonate alkalinities. For synthetic solution(100mg/L initial P, 50mg/L calcium, 100mg/L bicarbonate alkalinity, 0.025% seed dosage), the phosphorus concentration was examined with $10{\sim}35^{\circ}C$. In addition, calcinated eggshell was injected to swine wastewater to test the applicability to actual wastewater.