• Korean Journal of Optics and Photonics
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• v.6 no.2
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• pp.122-129
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• 1995

질소 기체의 온도변화에 따른 질소 레이저의 동작 특성을 조사하고 실험에 의해 얻은 E/P값을 이론치와 비교 연구하였다. 이를 위하여 레이저 관의 길이가 200mm이고, 다중 평행판 축전기형 전송 회로 및 질소 기체의 온도 조정 장치로 구성된 질소 레이저를 제작하였다. 반복률 20Hz에서 스파크 갭의 전극 거리 4mm일 때 최대출력을 얻었으며 최적동작 조건은 질소 기체 온도 $30^{\circ}C$, 기체 압력 70torr이었다. 이때의 E/P는 411V/cm.torr이었다. 한편 질소 기체의 온도가 증가함에 따라 최적 동작 조건은 높은 압력 쪽으로 이동하는 경향을 보였고 이때 E/P값은 감소하는 것으로 나타나 이론과 어느 정도 일치함을 알 수 있었다.

• The Korean Journal of Food And Nutrition
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• v.18 no.1
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• pp.39-47
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• 2005

Using the bacteria isolated from Chungkookjang, Bacillus sublilis MG410 which is excellent in fibrinolytic enzyme activity was isolated. In increase the high production of fibrinolytic enzyme from Bacillus sublilis MG410, the effect of various carbon sources, nitrogen sources, inorganic sources, the initial pH of medium were investigated. The most effective carbon and nitrogen sources were founded cellobiose 0.5%(w/v) and soybean meal 2%(w/v) respectively. None of inorganic sources examined had any detectable stimulating effect on fibrinolytic enzyme production except Na₂HPO₄·12H₂O. The initial optimum pH for fibrinolytic enzyme production ranged from 5∼6 and agitation speed was effect at 150rpm. In jar fermentor experiments under optimal culture conditions, the activity of fibrinolytic enzyme reached about 5.050 unit after 48hours.

• KSBB Journal
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• v.20 no.1 s.90
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• pp.26-33
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• 2005

The effects of carbon sources for exopolysaccharide production during batch cultivation of an Enterobacter sp. isolated from the composter were investigated. The highest amount of exopolysaccharide was obtained when lactose was used as carbon source. Lactose in medium was converted into glucose and galactose. Glucose was metabolized fast and was completely consumed, but about $20\%$ of lactose was accumulated as galactose. On the other hand, enzyme activity was about $350\~450$ unit with the increase of lactose concentration. Thus, it was considered that the exopolysaccharide might be produced in the course of that lactose was hydrolyzed into glucose and galactose by $\beta-galactosidase$ with respect to that enzyme activity on lactose hydrolysis was accorded to the exopolysaccharide production. When glucose and galactose were added to lactose medium, respectively, it could be considered that glucose was as a repressor and galactose was as a inducer for $\beta-galactosidase$ synthesis even though the mechanisms were not elucidated. The increase of lactose concentration was almost ineffective to the specific growth rate $(0.133\~0.151\;hr^[-1})$ but showed the difference in the biomass content. The higher carbon source concentration, the more residual sugar remained. It was assumed that the optimum lactose concentration for exopolysaccharide production was $30\~70g/L.$ On the other hand, it was considered that the nitrogen acted as growth limiting nutrients to the cell growth. In the cases of 30 and 70 g/L of the fixed carbon concentrations, the increase of the nitrogen sources concentration caused a remarkable increase within the range of $0.059\~0.225\;hr^{-1}$ and $0.141\~0.237hr^{-1}$ of the specific growth rate, respectively, while there was no significant difference in biomass.

• Research in Plant Disease
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• v.12 no.2
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• pp.85-90
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• 2006

Bacillus subtilis BD0310 isolated from tea leaves was used for the development of a biofungicide against Pestalotiopsis longiseta causing gray blight of tea plants. The optimum growth conditions were investigated for the mass cultivation of the microbial agent. The optimum temperature and cultivation time were determined as $12{\sim}24$ hours at $30^{\circ}C$ and the optimum initial pH was pH 7.0 in nutrient broth. Among the tested carbon sources of fructose, galactose, glucose, glycerol, inositol, lactose, maltose, sorbitol and starch, maltose and inositol were found to highly increase antifungal activity of the microbial agent against P. longiseta. Yeast extract and tryptone apparently increased antifungal activity of the microbial agent among the tested nitrogen sources of casein, tryptone, malt extract, yeast extract and $(NH_4)_2SO_4$. The results will make a contribution to mass production of the antagonistic bacterium Bacillus subtilis BD0310 for development of a microbial agent controlling gray blight of tea plants.

• Proceedings of the Korean Society of Plant Biotechnology Conference
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• 2005.04a
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• pp.188-188
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• 2005

• Applied Biological Chemistry
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• v.23 no.4
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• pp.211-217
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• 1980

Using Streptomyces chibaensis, which produces a strong inulin-hydrolyzing enzyme, the optimum cultural conditions and composition of the medium for the production of inulase were studied. 1. The highest enzyme activity was obtained at pH 7.5 after 84 hours culture at $30^{\circ}C$. 2. None of carbon source better than inulin was found. 3. $(NH_4)_2HPO_4$ and corn steep liquor were favourable inorganic and organic nitrogen sources for the production of inulase. 4. $KCl,\;MgSO_4\;and\;FeSO_4$ as the metallic salts were effective for the enzyme production at their concentrations of 0.01, 0.05 and 0.0001%, respectively. 5. The highest production of inulase was obtained from the medium of inulin 1.0% and corn steep liquor 2.0% concentrations, respectively.

• Journal of Mushroom
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• v.18 no.4
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• pp.311-316
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• 2020

The effect of the nitrogen content of sawdust medium (1.2~1.8%) and the restriction stage temperature (2, 4, and 6℃) on the growth and storage characteristics of Flammulina velutipes (winter mushroom) were investigated. With increased nitrogen content, the growth days shortened and the yield of the fruiting body increased. The effect of restriction temperature on the growth of the fruiting body differed depending on the nitrogen content. No difference in restriction temperature was evident for T1 with a low nitrogen content of 1.28%. In medium with a nitrogen content ≥1.55%, the yield and length of the pileus and stipe increased as the restriction temperature decreased. The weight loss ratio according to the storage period did not change according to the nitrogen content in the medium. A low weight loss ratio of 1.50 to 1.93% was observed at a restriction temperature <4℃. When T3 with high nitrogen content in the medium was treated at a restriction temperature of 4℃, the fruiting body color values after 31 days of storage were 84.81 (L) and 6.3 (ΔE). This color change was minute compared to that after other treatments. The sensory characteristics score was 5.2 after 31 days of storage, and the quality remained acceptable for consumption.

• Korean Chemical Engineering Research
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• v.44 no.1
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• pp.52-57
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• 2006

Bacterial cellulose (BC) was produced by Gluconacetobacter hansenii PJK (KCTC 10505 BP) strains using the waste of beer fermentation broth. It contained more C and N than a basal medium with a small amount of S and more than 4％ ethanol. The amount of BC produced in a shaking culture using the waste of beer fermentation broth was nearly the same as that of a basal medium. The production of BC decreased in a shear stress field in a jar fermenter although the conversion of cellulose producing ($Cel^+$) cells to non-cellulose producing ($Cel^-$) mutants was not severe. This study showed that the waste of beer fermentation broth is an inexpensive carbon, nitrogen source with ethanol and thus a worthy substitute for the conventional medium for BC production.

• Journal of Life Science
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• v.14 no.1
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• pp.126-130
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• 2004

This study was carred out to get the basic conditions for the mycelial growth of Morchella esculenta in shaking flask culture. The optimal temperature and initial pH of mycelial growth of Morchella escuzenta were 25$\pm$1$^{\circ}C$ and 6.5, respectively. The optimal medium was BG medium. Among the carbon sources tested, fructose was favorable for the mycelial growth and optimal fructose concentration was 5.0% (w/v). As nitrogen sources, peptone and NH$_4$Cl appeared to be favorable and optimal concentration was 4.0% [(w/v), ratio of 1:1].

• Journal of the Korean Society of Food Science and Nutrition
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• v.20 no.2
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• pp.179-186
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• 1991

The nutritional requirement and cultural condition such as carbon and nitrogen sources, cultural temperature, initial pH, cultural time and aeration for the production of endocellular cytosine deaminase from Aspergillus fumigatus IFO 5840 were investigated. The cultural broth giving maximum cytosine deaminase yield was found to consist of 2% glucose as a carbon source and 1% yeast extract and 0.1% peptone as a nitrogen source. Optimal initial pH of the culture broth was pH 8.5 and the enzyme production in the cell usually reached a maximum after 28 hours of cultivation in the 500ml shaking flask containing 100ml broth at $30^{\circ}C$. The endoenzyme production of the used strain was inhibited by inorganic nitrogen, but activated by orgainc nitrogen, yeast extract.