• KSBB Journal
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• v.10 no.1
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• pp.55-62
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• 1995

The functional relationship between the initial cell concentration and the ethanol productivity was investigated in the repeated batch fermentation of Sacharomyces cerevisiae ATCC 24858. The repeated batch fermentations were performed in the range of 60 to $150g/\ell$ of initial sugar concentration and 17.5g/$\ell$ to $53.1g/\ell$ of initial cell concentration. The time of one batch fermentation was 1 or 2 hours and the batch fermentation was repeated ten times in every repeated formentaction. The functional relationship showed that the productivity increased non-linearly according to the increase of initial cell concentration regardless of initial sugar concentration. When the initial concentration of sugar was $60g/\ell$ and that of biomass was $34.5g/\ell$, the fermentation was completed within one hour and its ethanol productivity was $26.7g/\ell$.hr, the latter including the times of cell separation, pouring the new substrate into a flask and sampling. When the initial sugar concentration was $120g/\ell$ and the initial cell concentration $50.3g/\ell$, the fermentation was also finished within one hour and its productivity was $45.8g/\ell$$.$hr, The maximum ethanol productivity for eight different repealed fermentations in this work was $53g/\ell$.hr.

• Microbiology and Biotechnology Letters
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• v.9 no.1
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• pp.7-19
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• 1981

The production of gluconic acid from glucose by the resting cell system of Aspergillus niger was studied. It was found that the conversion products from glucose by the resting cell system were markedly influenced by the pH, temperature, substrate concentration, aeration, metal ions, cultivation time and storage conditions of the resting cells. Conversion products were identified as gluconic acid by the thin layer chromatography and infrared spectrophotometry. These conversions were greatly stimulated by addition of $Mg^{++}$, and S $n^{++}$, but showed inhibitory effects by C $u^{++}$, H $g^{++}$, C $d^{++}$, A $g^{+}$ and cyanide. For the optimum cell storage, it was effective to be kept at -$25^{\circ}C$ in 0.05M phosphate buffer solution of pH 7.0. The gluconic acid production by the resting cell system was more effective than those of the fermentation with respect to cultivation time, yield, recovery and re-use of the cell.l.l.l.l.l.l.

• KSBB Journal
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• v.17 no.6
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• pp.555-559
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• 2002

Three different strains of Aureobasidium pullulans were grown in batch cultures to compare their abilities of enzyme production. It was found that specific enzyme activity was the highest with strain ATCC 9348 and the enzyme production was closely coupled to growth. Studies on morphology during the growth of A. pullulans revealed that mycelia cells were dominant at the initial stages of growth. However, yeast-like cells and chlamydospores were dominant in the latter stages of batch culture. The pattern of morphological changes during the growth period was not affected by pH. However, it appears that the ratio of intra- to extracellular enzyme activity tended to increase with fermentation time irrespective of the pH employed, suggesting that the secretion efficiency of intracellular enzyme to broth likely depends on cell morphology Using molasses as a cheap source of sucrose, enzymatic production of fructo-oligosaccharides as a feed additive with A. pullulans cells could be achieved successfully at 55$\^{C}$ and pH 5.5.

• The Korean Journal of Mycology
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• v.27 no.1 s.88
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• pp.82-86
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• 1999

The production of hepatoprotective exo-polysaccharide by using synthetic and industrial grade media of the submerged mycelial culture of Ganoderma lucidum WK-003 was compared. The optimum concentrations of molasses and corn steep liquor (industrial grade) for the production of exo-polysaccharide were 5% and 2.5%, respectively. The productions of the exo-polysaccharide by using a 5l jar fermenter with industrial grade medium and synthetic medium were 11.2 g D.W./l and 7.2g D.W./l, respectively. Glutamic pyruvic transaminase (GPT) activities in the serum of intoxicated Sprague-Dawley rats by oral administration of the exo-polysaccharide produced from the industrial grade and synthetic media for 4 consecutive days were decreased from 704 IU/L to 356IU/L and 704IU/L to 349IU/L, respectively.

• Korean Journal of Agricultural Science
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• v.4 no.1
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• pp.105-111
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• 1977

Inhibitory effect of sugars on lipase production by Trichosporon cutaneum was observed in the previous study (Kim, 1972), and inhibition was distinctive by the addition of glucose, fructose, mannose, xylose and arabinose to the soybean meal medium among various carbon sources. These experiments were carried out to study the effect of sugars on cell growth and lipase production by the strain using the soybean extracts liquid medium under a shaking culture system. Changes in color and pH of the medium were caused by heat sterilization when various sugars were added. To elucidate the possible effect of these coloring matters on lipase production and cell growth: changes in pH of the culture, cell concentration and level of the enzyme activities were determined when the culture was grown for 48 hours at $30^{\circ}C$ on a reciprocal shaker. The results obtained were as follows: 1. Density of brownish color which formed during heat sterilization was varied with the variety of sugar used, ie, strong in pentose such as xylose: weak in hexose such as galactose, mannose, glucose: very weak in disaccharide such as maltose, sucrose. When the color density was stronger, decrease in pH after sterilization was marked. 2. Cell growth and lipase production was not so effect by the coloring matters as by sugars. 3. The more the cell mass of the culture, the lower the level of lipase production in the culture supernatant. 4. Among the sugars which caused the distinctive inhibition of lipase production, a slight relief of inhibition was noticed by the addition of xylose, whereas the cell growth was repressed. 5. When cell growth was better, decrease in pH of the medium was greater during cultivation.

• Microbiology and Biotechnology Letters
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• v.26 no.3
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• pp.244-249
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• 1998

An extracellular polysaccharide, methylan, was produced under the specific conditions by Methylobacterium organophilum from methanol. The specific growth rate of cells was approximately constant regardless of C/N ratio and the specific product yield was maximum at a C/N ratio of 30. Methylan production was suppressed by the deficiency of mineral ions such as Mn$^{++}$ or Fe$^{++}$ ion. The optimal pH for cell growth and methylan production was 7. Whereas the optimal temperature for cell growth was found to be 37$^{\circ}C$, that for methylan production was 3$0^{\circ}C$. The methanol concentration above 4% completely inhibited the cell growth. The initial methanol concentration for the maximal production of methylan was 0.5% (v/v) and above this concentration, methylan production was markedly inhibited. To overcome the substrate toxicity and inhibition for both cell growth and methylan production, a fed-bach culture of intermittent feeding within 5 g/l methanol was conducted under the optimal culture condition. Methylan production of was stimulated by nitrogen limitation and methylan was accumulated up to 8.7 g/1 and cell mass also increased up to 12.4 g/l.

• Proceedings of the Korean Society for Applied Microbiology Conference
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• 1976.10a
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• pp.186.3-187
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• 1976

섬유소단세포단백의 공업적 생산을 위하여 실험적인 결과를 토대로하여 Jar Fermentor에 의한 scale up 실험을 하였고, pilot plant scale의 발효조를 이용하여 대량생산 실험을 하였는 바 그 결과를 발표하고자 한다. 1. 배양중 생성되는 유기산을 중화하기 위하여 주입되는 암모니아의 소비량과 균체농도는 배양종반을 제외하고는 거의 비례하였으며 암모니아소비량으로 균체생육 정도를 간접적으로 판단할 수 있었다.(중략)

• Journal of the Korea Organic Resources Recycling Association
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• v.13 no.4
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• pp.100-106
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• 2005

Sugar beet stillages were used as a substrate for the production of single cell protein by the thermotolerant yeasts Candida rugosa, Kluyveromyces marxianus and C. utilis. The biomass production increased in accordance with the increase of pH-value, but protein content decreased. C. rugosa showed the highest crude protein production as 3.68g/l and C. utilis 2.9g/l, Kl. marxianus 2.30g/l, respectively. The rate of COD reduction in stillage versus crude protein production of C. rugosa showed the highest value as 0.35~0.39g/l as a good strain for single cell protein production using sugar beet stillages.

• Applied Biological Chemistry
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• v.41 no.5
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• pp.331-336
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• 1998

The possibility of using waste brine from kimchi factory as a substrate for the production of the single cell protein was investigated. The growth of Pichia guilliermondii A9 isolated from waste brine was not inhibited by the NaCl up to 10% (w/v). BOD of the waste brine was reduced to one tenth after 24 hours of yeast culture. The addition of ammonium salt, phosphate, and micronutrients to the waste brine did not enhance the growth of P. guilliermondii A9. However, when the brine was enriched with juice from waste cabbage, the final cell mass increased proportionally with the amount of added organic material, suggesting a practical application for the treatment of two different types of waste produced during kimchi manufacturing.

• Journal of Life Science
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• v.2 no.3
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• pp.175-179
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• 1992

광조사시에 수소를 생산하는 미생물로는 녹조류, 남조류 그리고 광합성세균이 알려져 있으며, 이 중에서 남조류와 광합성세균이 실용적인 수소생산에 유망시되고 있다. 광합성세균은 광학계 II가 결여되어 물분해능이 없으나 유기화합물을 전자공여체로하여 남조보다 훨씬 빠른 속도로 수소를 생산하며, 생산가스는 약간의 이산화탄소 외에는 거의 순수한 수소여서 그대로 연료로 사용할 수 있는 장점을 지닌다. 본고에서는 공합성세균에 의한 수소생생의 연구현황과 문제점에 대해 다루었다. 광합성세균에 의한 수소생산의 실용화를 위해서는 균체의 수소생산성 향상 및 활성의 유지, 원료문제 및 암모니아에 의한 수소 생산의 억제문제, 적합한 배양조개발과 균체의 이용방안 등에 관련된 제분제의 해결이 필요하다. 광합성세균의 수소생산성 향상을 위해서는 자연계로부터 보다 고활성균주의 탐색과 아울러 유전적인 개량이 병행되어야한다.