• 한국유기농업학회지
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• 제6권1호
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• pp.85-98
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• 1997

Cultural conditions for mass production of the antagonistic bacteria, Bacillus subtills CAP141 against pathogens causing major airborne diseases to apple trees, effects of temperature, pH, carbon and nitrogen source in the culture broth were investigated. The bacterial growth was most vigorous when the temperature and pH of the culture broth was 30~35$^{\circ}$C and 7, respectively. As for carbon source, dextrose was best followed in order by dextrose(monosaccharide) > sucrose(disaccharide) $\geq$ saccharose (market disaccharides) > starch (polysaccharieds). Among different sugars, bacterial growth was favored by in the order of brown, black and white supars, indicating that the bacterial growth might be promoted by the minor elements presented as impurities in the less purified sugars. As for nitrogen source, organic forms were better to bacterial growth than inorganic forms, that is polypeptone was best followed in order by soy sauce, soybeen milk and inorganic nitrogens. Differences in bacterial growth among different forms of inorganic nitrogen were negligible.

• Journal of Applied Biological Chemistry
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• 제49권3호
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• pp.106-109
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• 2006

Improvement of L-asparate ${\beta}-decarboxylase$ production from Pseudomonas dacunhae ATCC 21192 was attempted by optimizing fermentation conditions. Optimum carbon and nitrogen sources for cell growth and enzyme production were determined. L-Glutamate (2%) was the most suitable carbon source, and D-glucose, D-glycerol and fumarate repressed enzyme production. Yeast extract (2%) was the most effective as nitrogen source. A slight change of pH to 6.5 from medium pH resulted in a meaningful increase in the production of enzyme. The production of the enzyme was highly improved by using 2% yeast extract and 2% L-glutamate in culture media. Maximum L-asparate ${\beta}-decarboxylase$ activity reached up to over 24 U/mL-broth by 15 h flask fermentation.

• 분석과학
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• 제8권4호
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• pp.553-559
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• 1995

An extraction chromatographic method of separating rare earth impurities from high purity $Nd_2O_3$, $Sm_2O_3$, $Gd_2O_3$, $Er_2O_3$, $Dy_2O_3$ and $Yb_2O_3$ was studied by using $HCl-NH_4Cl$ as moving phase and P507 as stationary phase. After the impurities were enriched from the eluate by chelant-activated carbon, the active carbon was ashed and the ignited residue was used to prepare the sample electrode for spark source mass spectrometric determination. The impurities in 99.9999% rare earth oxide can be determined by the proposed method with recovery over 80%.

• Journal of Microbiology and Biotechnology
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• 제6권6호
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• pp.397-401
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• 1996

A bacterial strain CFCl, which produced an extracellular cycloinulooligosaccharide fructanotransferase(CFTase), was isolated from soil. The isolated strain was identified as a strain of Bacillus sp. The synthesis of CFTase by the bacterium was found to be induced by inulin which was added to the culture medium as a carbon source. The highest activity of CFTase was observed at pH 7.5 and $37^{\circ}C$ in the medium containing 4% inulin and 0.5% peptone as a carbon source and a nitrogen source, respectively. Under the optimal conditions, the enzyme activity in the culture supernatant reached the highest level of 85 munits/ml after 96 h cultivation.

• Asian Journal of Atmospheric Environment
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• 제7권2호
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• pp.95-104
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• 2013

The study of carbonaceous aerosols in the atmosphere is critical to understand the role of aerosols in human health and climate. Using standardized thermal optical transmittance methods, organic carbon (OC), elemental carbon (EC), and water soluble organic carbon (WSOC) were determined using a combustion sampling system for four types of agricultural crop residues (rice straw, red pepper stems, soybean stems, and green perilla stems) and eight types of forest trees (pine stems, pine needles, ginkgo stems, ginkgo leaves, maple stems, maple leaves, cherry stems, and cherry leaves). The aerosol particles between 0.056 and $5.6{\mu}m$ in size were analyzed using a Micro-Orifice Uniform Deposit Impactor (MOUDI). In the current study, the Carbonaceous Thermal Distribution (CTD) by carbon analyzer was discussed in order to understand the carbon fractions from the twelve types of biomass burning. Also, the concentration of OC, EC, WSOC, and water insoluble organic carbon (WIOC) detected in the emissions were described.

• 공기청정기술
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• 제11권3호통권42호
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• pp.15-40
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• 1998

Recently, many environmental problems have been reported, which are caused by the utilization of fossil fuel. Eepecially, carbon dioxide from fossil fuel combustion is thought to be a main source of the global warming which affects the global environment.

• Carbon letters
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• 제16권4호
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• pp.255-259
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• 2015

• 한국미생물·생명공학회지
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• 제17권6호
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• pp.568-573
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• 1989

탄소원과 질소원, 배지의 초기 pH 및 C/N비가 Mucor sp. KCTC 8405P의 감마 리놀렌산 생산에 미치는 영향을 조사하였다. 탄소원으로는 포도당이, 질소원으로는 황산 암모늄같은 무기 질소원과 요소, 펩톤같은 유기질소원이 균체 유지함량 및 감마 리놀렌산 수율 측면에서 양호한 것으로 판명되었다. 사용하는 질소원은 일정농도 이하로 제한할 필요가 있으며 포도당과 황산 암모늄을 사용할 경우 최적 C/N비는 약 56.6으로 조사되었다. 균체 유지함량을 증가시키기 위한 배지의 초기 pH는 8 또는 9가 유리한 것으로 나타났으며, 포도당과 sodium acetate를 혼합하여 탄소원으로 사용하는 것이 바람직한 것으로 조사되었다. 3% 포도당과 2% sodium acetate 를 탄소원으로, 0.1% 황산암모늄을 질소원으로 포함하는 배지를 사용하여 플라스크 교반배양을 실시한 결과 배지 100$m\ell$ 당 약 315mg의 균체유지량을 얻었고, 이중 감마 리놀렌산 함량은 약 13-14%로 조사되었다.

• 상하수도학회지
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• 제35권6호
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• pp.405-415
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• 2021

MMBR system has been suggested as a promising system to resolve harvesting problems induced from low settling efficiency of microalgae. And recently, a lot of research on reducing fouling at the MMBR system has investigated focused on EPS in many cases. EPS of microalgae mainly consists of polysaccharides and protein components, and is produced through photosynthesis and nitrogen-carbon metabolic pathways. Especially, P-EPS is one of major compounds which occur membrane fouling phenomenon, as its hydrophobic protein components cause floc formation and cake layer accumulation. And it is already known that almost every microalgae can metabolize P-EPS or Chl-a when nitrogen sources as a substrate is insufficient or exhausted situation. With the above backgrounds, uptake rates of P-EPS or Chl-a by Scenedesmus quadricauda according to the type of carbon source and nitrogen concentration were evaluated in order to verify correlation between carbon source vs P-EPS production, and indeed Scenedesmus quadricauda uses P-EPS or Chl-a when the amounts of nitrogen sourc es in the feed is not satisfied. As a result, it was shown that P-EPS and Chl-a production were increased proportional to nitrogen concentration under organic carbon condition. And especially, the amo unts of P-EPS and Chl-a in the cell were diminished with the nitrogen source becomes insufficient or exhausted. Because P-EPS accelerates fouling at the MMBR system, P-EPS degradation by Scenedesmus quadricauda in order to get nitrogen source may contribute to reducing fouling. About a affects of N-consumed Chl-a to the MMBR fouling, more survey is needed. On the contrary, considering the purpose of MMBR system of this study, i.e. harvesting useful high value microalgae efficiently feeding adequate industrial process wastewater, it seems like difficult to maintain satisfied metabolic activity and to harvest with high yield rate using nitrogen-poor MMBR feed.

• 한국결정성장학회지
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• 제17권4호
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• pp.160-164
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• 2007

Carbon nanofibers were deposited on silicon oxide substrate by thermal chemical vapor deposition method. For the enhancement of the characteristics of carbon nanofibers, the source gases ($C_2H_2,\;H_2$) flows were intentionally manipulated as the cyclic on/off modulation of $C_2H_2$ flow. By the cyclic modulation process during the initial deposition stage, the formation density of carbon nanofibers on the substrate could be much more enhanced. The diameter of as-grown carbon nanofibers was also reduced by the cyclic modulation process. The cause for the variation in the characteristics of carbon nanofibers by the cyclic modulation process was discussed in association with the hydrogen gas etching ability.