• 한국신재생에너지학회:학술대회논문집
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• 2008.05a
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• pp.591-594
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• 2008

지구 온난화 문제의 심각성이 대두되면서 이산화탄소 저감 기술에 대한 관심이 증폭되고 있다. 가장 이상적인 방법은 탄소가 포함되지 않은 청정 재생 에너지원이지만, 에너지 공급 규모 면에서 보면 근미래에도 화석 연료가 에너지 수요에 대한 주요 공급원으로 남아있을 것이라는 의견이 지배적이다. 많은 화석 연료 중 천연가스는 탄소 배출량이 가장 적은 청정 연료로 지난 10년간 수요가 폭발적으로 증가해왔다. 이를 고려해볼 때 탄소 배출량이 적은 천연가스를 생산하면서 이산화탄소를 격리 시킬 수 있는 기술은 매우 매력적이다. 본 연구에서는 심해저의 메탄 하이드레이트로 부터 천연가스를 생산하는 기술로서 이산화탄소와 질소의 혼합 가스를 사용하는 기술 개발의 일환으로 혼합 가스에 의한 메탄 하이드레이트 해리 속도를 $^{13}C$ NMR을 이용해 측정한 결과를 제시하고자 한다.

• 한국방재학회:학술대회논문집
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• 2008.02a
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• pp.803-806
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• 2008

LEACHN is the computer simulation model which can be used to simulate field-scale N transformations and movement and has three organic pools (plant residue, manure, and soil humus), three inorganic pools (urea, nitrate and ammonium) and plant. Pot experiment operated May to October in 2004. LEACHN simulated the nitrogen movement and transformation in soil using method of PEST and trial and error.

• Journal of Mushroom
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• v.7 no.1
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• pp.27-36
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• 2009

Pleurotus ferulae is an edible mushroom found on a medicinal plant, Ferula assa-foetida, in centeral China. This study was carried out to investigate the cultural characteristics of P. ferulae strains. Characteristics of mycelial growth were investigated for 5 strains of P. ferulae. All the 5 strains showed the best mycelial growth at $25^{\circ}C$ and their growth rate was very low at $35^{\circ}C$. The colony diameter reached to 45~72 mm after 7 days at $25^{\circ}C$. Malt extract agar medium was the best for mycelial growth of the species both in hyphal length and density. Mycelial growth was not affected by various pH from 6.0 to 8.0. An optimal carbon source was arabinose and an optimal nitrogen one was arginine. And an effective substrate for the mycelial growth was 8 to 2 mixture of oak sawdust and cottonseed meal.

• 한국신재생에너지학회:학술대회논문집
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• 2010.06a
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• pp.219.1-219.1
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• 2010

매립지에서 유기물의 분해로 발생되는 매립가스는 악취 등으로 인한 대기오염뿐만 아니라 온난화지수가 21인 메탄이 약 50vol% 포함되어 있어 지구온난화에 큰 영향을 미친다. 하지만 매립가스를 에너지원으로 활용하면 대기오염저감, 지구온난화 감소, 대체에너지원 확보뿐만 아니라 CDM사업 등과 연계하여 부가수익창출이 가능하다. 현재 국내에는 약 242개의 폐기물매립지가 있는데, 이중 매립가스를 활용하는 곳은 단지 14개소로 개별 경제성이 있는 대형매립지에서만 자원화시설을 설치하여 운영 중이며 그 외 매립지에서는 매립가스를 소각 또는 단순 대기 방출하여 대기오염유발과 동시에 대체에너지원 미활용으로 국가차원에서 큰 손실이므로 이를 활용할 수 있는 기술개발이 시급하다. 본 연구에서는 중소규모 매립지에서 발생하는 매립가스를 중심적환장으로 이송하여 경제성을 가지는 에너지원으로 활용할 수 있는 기술개발을 목표로 하이드레이트 기술을 접목한 기초연구를 수행하였다. 매립지에서 매립가스가 생성되는 과정에 표층부의 균열 및 차수막의 손상과 포집하는 공정에서 블로워 등의 사용으로 질소가 다량 포함되며 질소의 경우 상당히 높은 압력과 낮은 온도에서 하이드레이트를 형성하므로, 매립가스 하이드레이트 형성시 질소의 영향에 대해 알아보았다. $CH_4+CO_2$ System과 $CH_4+O_2+N$ System에 대하여 각각의 실험조건에서 Kinetic을 측정하였으며, 실험전후의 가스 조성을 Gas Chromatography로 정성, 정량 분석하였다. 실험결과 매립가스에 공기가 유입될 경우, 질소의 영향으로 하이드레이트 생성조건이 가압되었고 하이드레이트 내 메탄의 함량비율이 줄어들었다.

• Food Science and Preservation
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• v.11 no.3
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• pp.405-410
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• 2004

Leuconostoc mesenteroides subsp. cremoris DLAB19 were investigated under various culture conditions to maximize the production of antimutagenic substance(s) against aflatoxin Bl(AFBl) on Salmonella enterica serovar Typhimurium TAI00 and TA98. The MRS medium containing glucose(2$\%$) as a carbon source and yeast extract(1 $\%$) as a nitrogen source resulted in the highest production of the antimutagenic substance(s) against aflatoxin Bl(AFBl) in the culture supernatant of Leu. mesenteroides subsp. cremoris DLAB19. Optimal pH of the medium, culture temperature and shaking speed for the antimutagenic substance(s) production were pH 7.0, 30$^{\circ}C$ and 150 rpm, respectively. Under the optimal condition, the antimutagenic effects of Leu. mesenteroides subsp. cremoris DLAB19 culture supernatant were 87.11 $\%$ on S. enterica serovar Typhimurium TA100 and 75.04 S. enterica serovar Typhimurium TA98.

• KSBB Journal
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• v.14 no.2
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• pp.160-166
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• 1999

High cell density cultivation of microalga Dunaliella bardawil using nitrogen fed-batch cultures was studied in batch flask. Optimum environmental conditions include concentrated nutrients except NaCl and carbon sources, carbon sources, pH, light, agitation, nitrate and phosphate ions. Cell growth, consumption rates of nitrate and phosphate ions were monitored. Optimal conditions for higher cell density were found to be(in the range tested): 5 times concentrated media(1 times-10 times concentrated media) pH 8.0 (7.0-9.0) white light(blue and red light) 15mM of nitrate (0.94-15mM) 250mM $NaHCO_3$ and $CO_2$ gas. However, the addition of phosphate ions did not enhance the algal maximum cell density and specific growth rate. Nitrate was found to be effective for the cell growth. The maximum cell density of fed-batch culture using nitrate ions in $8.955{\times}106$cells/ml after 189hr incubation.

• KSBB Journal
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• v.14 no.5
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• pp.572-577
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• 1999

A marine bacterium with highly effective agar degrading activity was ioslated from the southern sea of Korea (Chonnam, YoChon) and identified as Cytophaga sp. and named as Cytophaga sp. AYK301. This strain produced an extracellular agarase which had a high activity with agar. The optimum culture conditions for the production of agarase have been determined. For the increase of agarase productivity, 0.2% agar, 0.3% beef extract, and 0.05% NH$_4$NO$_3$ were used as carbon, organic and inorganic nitrogen source, respectively. The optimal initial pH, NaCl, culture time and temperature for the agar degrading activity were 7.5, 7.0%, 36 hr and $25^{\circ}C$, respectively. In the optimal conditions, the agarase production was increased up to more than 4.0 folds as compared to that by the basal medium.

• Korean Journal of Food Science and Technology
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• v.20 no.1
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• pp.79-84
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• 1988

${\alpha}$-Galactosidase from Aspergillus niger as a possible enzyme for removal of flatulence factors in soybean foods was produced the highest in 120 hours in either Czapeck-Dox liquid medium or wheat bran solid medium. The most efficient carbon and nitrogen sources in Czapeck-Dox medium were raffinose and sodium nitrate, respectively, whereas the addition of the sources showed negative effects in wheat bran. pH optima for enzyme activity and stability were 4.0-5.0 and 3.5-6.5, respectively, and optimum temperature for stability was $40-50^{\circ}C$. Upon reaction on p-nitrophenyl-${\alpha}$-D-galactoside, Michaelis constant was 0.42 mM and maximum velocity was 152 ${\mu}moles$ substrate/minute/kg solid medium. Mercuric chloride acted as a strong noncompetitive inhibitor and p-chloromercuribenzoate, even in low concentration, acted as a competitive inhibitor. Crude ${\alpha}$-galactosidase hydrolyzed raffinose and stachyose completely, giving spots of monosaccharides only on thin-layer chromatogram.

• Microbiology and Biotechnology Letters
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• v.8 no.2
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• pp.119-123
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• 1980

Culture conditions of yellow pigment in Monascus sp. were studied. According to the studies of culture conditions optimum condition was found to be pH 4.5, 3 days of incubation with 3% of sucrose as carbon source, 0.2 ％ of yeast extract as nitrogen source and 75m1 of medium in the 500m1 erlenmyer flask by rotary shaking (rpm 180) at 180 r.p.m. Effective levels of inorganic compounds were found to be 0.25 % of potassium phosphate monobasic and 0.1 ％ of Magnesium sulfate.

• Microbiology and Biotechnology Letters
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• v.7 no.1
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• pp.23-30
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• 1979

Fungi which produce red pigment were isolated from tapioca chips, Korean Koji, air, and plant leaves. Among the Fungi, T-1 strain was selected as test strain. This strain was identified as a Monatcus sp. by the morphological propeties. Various culture conditions, and physical and physiological characteristics of red pigment were studied. According to the studies of culture conditions, optimum condition was found to be pH 6.5; 4 days of incubation; temperature, 32~33 c: 3.5％ of Tapioca chips powder as carbon source, 0.2％ of sodium nitrate as nitrogen source and 100 ml of medium in the 500 ml Erlenmyer flask at a rotary shaker (rpm180) as aeration condition. Also effective levels of vitamins, amino acids and inorganic compounds was found to be l$\mu\textrm{g}$/ml of folic acid and niacin; 0.3％ of L-arginine, L-glutamic acid and L-proline; and 0.001％ of manganese dioxide giving good results.