• Journal of Microbiology and Biotechnology
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• v.14 no.2
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• pp.237-242
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• 2004

Cell growth and the production of pullulan by Aureobasidium pullulan HP-2001, the UV-induced mutant of A pullulans ATCC 42023, increased with increased concentration of glucose up to 15.0% (w/v). Maximal production of pullulan in the flask scale was 27.65 g/l, when concentrations of glucose and yeast extract were 15.0 and 0.25% (w/v), respectively. Maximal conversion rate of pullulan from glucose as the carbon source was 0.37, when those of glucose and yeast extract were 5.0 and 0.15% (w/v), respectively. On the basis of total amount of pullulan, the conversion rate of pullulan from glucose, and utilization rate of glucose to cell mass and pullulan by A. pullulans HP-2001, the optimal concentrations of glucose and yeast extract for the mass production of pullulan were determined to be 10.0 and 0.25% (w/v), respectively, at which concentrations the production of pullulan and its conversion rate were 27.14 g/l and 0.27, respectively. Maximal production of pullulan with optimized concentrations of carbon and nitrogen sources by A. pullulans HP-200l in a 7-1 bioreactor was 32.12 g/l for 72 h culture, and that in a 100-1 bioreactor with the inner pressure of $0.4 kgf/cm^2$ was 36.87 g/l. Increased inner pressure of a 100-1 bioreactor resulted in a higher concentration of dissolved oxygen in the medium, which might enhance the production of pullulan by A. pullulans HP-2001.

• Journal of Life Science
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• v.9 no.3
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• pp.293-299
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• 1999

Accumulation of toxic waste byproducts in hybridoma culture can limit cell growth and monoclonal antibody (MAb) productivity, and one of the major toxic metabolites is lactate produced via glycolytic pathway of glucose metabolism. The factors affecting the glucose to lactate conversion rate were investigated. The conditions of high initial glucose concentration and high growth rate stimulated glucose to lactate conversion rate. The glucose-controlled fed-batch culture was investigated, and 19% reduction in lactate formation and 41% enhancement of MAb titer could be achieved by fed-batch culture.

• Journal of Microbiology and Biotechnology
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• v.8 no.5
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• pp.543-546
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• 1998

The effect of glucose concentration on the production of erythritol by Trichosporon sp. was mainly studied. The specific growth rate and production rate of erythritol gave the highest values of $0.23 h^{-1}\; and\; 4.2 g/\ell/h,\; respectively,\; on\; 100 g \; glucose/\ell$ of medium. The conversion yield of erythritol during the exponential phase and the stationary phase was constantly maintained at 19% and 51 %, respectively, while the glucose concentration in the medium varied from 100 g/$\ell$ to 400 g/$\ell$. The maximum overall erythritol conversion yield of 47% was obtained when the glucose concentration in the medium was 400 g/$\ell$. It corresponded to a 74% increase compared with the 100 g/$\ell$ glucose medium. The diauxy growth of this microbe was also observed. It grew exponentially consuming glucose, then after the second lag phase, biomass slowly increased using glycerol and erythritol.

• 한국생물공학회:학술대회논문집
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• 2000.04a
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• pp.259-262
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• 2000

The production of pullulan by Aureobasidium pullulans HP-2001 was investigated under various ratios of glucose as carbon source and yeast extract as the nitrogen source, Highest conversion rate (productivity) of glucose to pullulan was 40.0% when concentrations of glucose and yeast extract were 5% and 0.15%, respectively. Maximal production of pullulan was 29.3g/1 when the concentration of glucose was 8%(w/v) and that of yeast extract was 40:1. On basis of the result that production of pullulan was found in a medium which concentration of glucose as carbon source was up to 20%(w/v), Aureobasidium pullulans HP-2001 seemed to overcome the catabolite repression. Conversion rate of pullulan from 20%(w/v) of glucose was 11.1%.

• Microbiology and Biotechnology Letters
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• v.20 no.5
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• pp.588-596
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• 1992

The fermentation characteristics of ethanol production by the use of immobilized Zymomonas mobilis KCTC 1534 cells were investigated in terms of formation factors such as substrate and product concentration. In batch fermentation, the maximum values of specific ethanol productivity, specific substrate uptake rate, ethanol yield, and glucose conversion rate were $29.14g/{\ell}{\cdot}h$, $60.24g/{\ell}{\cdot}h$, 0.48g/g, and 98.4%, respectively, with 17% glucose medium, and its ethanol productivity was $2.91g/{\ell}{\cdot}h$ in the case of 25 hour fermentation time. Repeated batch fermentation was possible for 30 days with 2.24-$2.94g/{\ell}{\cdot}h$ ethanol productivity. In semicontinuous fermentation, the maximum ethanol productivity was shown to be $15.7g/{\ell}{\cdot}h$ at $0.36h^{-1}$ effective dilution rate with 17% glucose concentration. In this case, ethanol yield coefficient and glucose conversion rate were 0.39 g/g, 64.7%, respectively.

• Journal of Yeungnam Medical Science
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• v.5 no.2
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• pp.79-86
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• 1988

In the present study the effect of exercise on the conversion rate of ingested glucose to glycogen in the different types of hindlimb skeletal muscles in Sprague-Dawley male rats was studied. The amounts of synthetized glycogen from ingested glucose of fast-twitch white(WV), fast-twitch red(RV), mixed type of fast-twitch white and red(EDL), and slow-twitch(SOL) muscles were determined at 30 and 90 min. after ingestion of 25% glucose solution which contained $^{14}C$-glucose($2m{\ell}(1uCi)$/100gm B. W.)in control and exercise loaded rats. The result was summarized as follows : The about 55% at 30 min. and 70% at 90 min. after glucose ingestion were absorbed from gastrointestinal tract. This result shows no effects of exercise on absorption rate from gastrointestinal tract. The amount of synthetized glycogen of SOL from ingested glucose at 30 and 90 min. after glucose ingestion were highest, whether WV were lowest in hindlimb skeletal muscles in control and exercise loaded rats. In the exercise loaded rats, the amounts of synthetized glycogen of SOL, RV, and EDL at 90 min. after glucose ingestion was much higher than control rats, but not different in WV between exercise-loaded and control rats. At 30 min. after glucose ingestion, only SOL of exercise loaded rats was higher than control rats. In the control rat, the synthesis of glycogen was almost completed during initial 30 minutes. On the other hand, in the exercise loaded rat, except WV was opposite result of control rats, i. e., amounts of synthetized glycogen were major during late period. The amount of synthetized glycogen of liver at 30 and 90 min. after glucose ingestion in exercise loaded rats was higher than control rats. The rate of glycogen synthesis in control and exercise loaded rats were higher between 30-90 minute than initial 30 minute.

• Microbiology and Biotechnology Letters
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• v.19 no.4
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• pp.398-404
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• 1991

- Ethanol production by calcium alginate-immobilized baker's yeast was studied in the continuous shaked-flask reactor (CSFR) using glucose medium as a feed. Immobilized cells were stable at 30~$37^{\circ}C$ and pH 4~8. Fermentation characteristics of immobilized baker's yeast were examined changing the initial glucose concentration employed were 50, 100 and 150 g/l, respectively. It was investigated that the influent glucose concentration and the dilution rate have an influence on the ethanol fermentation characteristics at steady state in continuous culture of immobilized baker's yeast. The optimum conditions for high ethanol productivity and low residual glucose output in ethanol prodution were shown to be 0.2 h ' for the dilution rate and 150 g/l for the influent glucose concentration. The maximum ethanol productivity, ethanol yield, specific growth rate and glucose conversion rate were around 7.12 g/$l\cdot h$, 0.23, 0.366 g/$l\cdot h$ and 78.43, respectively.

• Microbiology and Biotechnology Letters
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• v.23 no.6
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• pp.723-729
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• 1995

A flocculating sugar tolerant yeast strain was isolated from fermenting Takju. This strain was identified as Saccharomyces cerevisiae CA-1 according to the Lodder's yeast taxonomic studies. The isolated yeast could grow in 50% glucose and in 7% ethanol in the YPD medium. It's optimal growth temperature, initial pH, shaking rate and initial glucose concentration for ethanol fermentation showed 35$\circ$C, 4.5, 150 rpm, 15%, respectively. Ethanol concentration was 63 g/l in 20% glucose after 24 hours, fermentation yield was 0.49 g-ethanol/g-glucose in 10% glucose after 24 hours and ethanol productivity was 3.09 g/l$\cdot $h in 10% glucose after 12 hours in batch fermentation. Repeated batch fermentation was possible for over 50 days and ethanol yield, ethanol productivity and substrate conversion rate were 0.39-0.50 g/g, 1.63-2.08 g/l$\cdot $h and more than 99%, respectively during these periods.

• Korean Journal of Environmental Agriculture
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• v.11 no.3
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• pp.215-223
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• 1992

A metabolic study has been conducted to investigate the conversion of pentachlorophenol(PCP) to water soluble metabolites in soybean and rice cell suspension cultures as well as in intact rice plants. PCP in plant cells was found to be exclusively transformed into water soluble metabolites. The relative rate of the metabolic conversion of PCP in decreasing order was soybean cultures > rice cultures > rice plants. Also observed was that, the older the cultures grown, the lower the conversion rate was. Primary water soluble metabolites isolated from both the 5 day old soybean and 8 day old rice cells were specifically hydrolyzed only by ${\beta}$-glucosidic linkage specific glucosidase, suggesting that the metabolites are ${\beta}$-glucose conjugates. The amount of glucose conjugates was increased with increasing time of incubation of PCP up to 24 hr in both soybean and rice cultures; Thereafter, it was decreased progressively. Most of the glucose conjugates were further metabolized to more polar conjugates in cells, but a portion of them was excreted into the culture medium.

• 한국생물공학회:학술대회논문집
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• 2000.11a
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• pp.384-387
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• 2000

Heteropolysaccharide-7 (PS-7) was produced by Beijerinckia indica HS-2001 under aerobic condition. Production of PS-7 was investigated under various ratios of glucose as carbon source to ammonium nitrate as nitrogen source. Maximal production of PS-7 was 7.13 g/l when concentrations of glucose and ammonium nitrate were 10 g/l and 0.3 g/l, respectively. But its conversion rate from glucose was as low as 7 %. The highest conversion rate of PS-7 was 46% when those of glucose and ammonium nitrate were 1.0 g/l and 0.3 g/l, respectively.