• Journal of Microbiology and Biotechnology
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• v.26 no.8
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• pp.1348-1357
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• 2016

An enzymatic reaction system was developed and optimized for bioconversion of resveratrol from glucose. Liquid enzyme extracts were prepared from Alternaria sp. MG1, an endophytic fungus from grape, and used directly or after immobilization with sodium alginate. When the enzyme solution was used, efficient production of resveratrol was found within 120 min in a manner that was pH-, reaction time-, enzyme amount-, substrate type-, and substrate concentration-dependent. After the optimization experiments using the response surface methodology, the highest value of resveratrol production (224.40 μg/l) was found under the conditions of pH 6.84, 0.35 g/l glucose, 0.02 mg/l coenzyme A, and 0.02 mg/l ATP. Immobilized enzyme extracts could keep high production of resveratrol during recycling use for two to five times. The developed system indicated a potential approach to resveratrol biosynthesis independent of plants and fungal cell growth, and provided a possible way to produce resveratrol within 2 h, the shortest period needed for biosynthesis of resveratrol so far.

• Korean Journal of Chemical Engineering
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• v.35 no.12
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• pp.2413-2420
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• 2018

Sida acuta, a common type of weed in Thailand, contains relatively high cellulose (42.7%) content. We pretreated NaOH to improve glucose recovery from S. acuta. The effect of pretreatment temperature and NaOH concentration was fundamentally investigated based on hydrolysis efficiency with recovery of solid fraction. The pretreatment condition was determined to be 3% NaOH at $60^{\circ}C$ for 9 h, which showed the highest glucose recovery. The hydrolysates obtained by enzymatic hydrolysis of S. acuta were applied to the fermentation of Saccharomyces cerevisiae K35, and a theoretical yield of 97.6% was achieved at 18 h. This indicated that the hydrolysates medium without detoxification had no negative effects on the fermentation. The production of biomass into bioethanol was evaluated based on the material balance of 1,000 g basis. Following this estimation, approximately 28 g and 110 g bioethanol could be produced by untreated and pretreated S. acuta, respectively, and this production was improved about 3.9-fold by NaOH pretreatment. These results again show the importance of pretreatment in biorefinery process.

• Food Science and Preservation
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• v.15 no.2
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• pp.311-316
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• 2008

We studied changes in a high-proof maesil liqueur during a 5 month leaching and ripening period at $10^{\circ}C,\;20^{\circ}C$, and $30^{\circ}C$. Titratable acidity increased after 2 months at all temperatures, but pH only changed after 2 months at $30^{\circ}C$. The absorbance at 420 nm increased significantly during a high temperature leaching and ripening period. The alcohol concentration was similar for maesil liqueurs held at $10^{\circ}C$ and $20^{\circ}C$ for 2 months. The levels of reducing sugars and polyphenols were also higher for liqueurs stored at higher temperatures. The major free sugars present after one month (in order of decreasing concentration) were fructose, glucose, sucrose, and maltose. The major organic acids were citric, lactic, malic, succinic and acetic acid The total organic acid content of maesil liqueur decreased after 1 month at $10^{\circ}C$ but increased until 2 months at $20^{\circ}C$ and $30^{\circ}C$.

• Korean Journal of Poultry Science
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• v.39 no.3
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• pp.215-222
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• 2012

This study was conducted to investigate the effects of supplementation diets of powdered mulberry leaves on egg production, egg quality and blood characteristics in laying hens. Laying hens were fed diets for 30 days containing 0% powdered mulberry leaves (Control), 1% powdered mulberry leaves (T1), 2% powdered mulberry leaves (T2), and 5% powdered mulberry leaves (T3). The egg production, yolk weight and albumen weight were no significant difference among treatment groups. The albumen weight was significantly decreased by the supplementation of powdered mulberry leaves in all treatment groups (P<0.05). The albumen high, yolk color score, egg sell thickness and egg shell breaking strength were no significant difference. The total cholesterol and triglyceride concentration of control was higher than T3, and the high density lipoprotein (HDL)-cholesterol concentration and glucose of control were lower than treatment groups (P<0.05). The white blood cell (WBC) was significantly increased by the supplementation of powdered mulberry leaves compared to the control (P<0.05). In conclusion, these data indicate that 5% powdered mulberry leaves supplementation was most effective in decreasing total cholesterol and triglyceride and increasing HDL-cholesterol, glucose and WBC.

• Applied Biological Chemistry
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• v.38 no.6
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• pp.507-511
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• 1995

In an attempt to improve the productivity of ${\beta}-galactosidase$ from Bacillus sp. A1, which was isolated from soil and has remarkably higher transgalactosylation activity than lactose hydrolysis activity, a chemical mutation procedure using N-methyl-N'-nitro-N-nitrosoguanidine followed by selection was conducted. The final selection, designated as Bacillus sp. A4442, turned out to show a substantially increased enzyme productivity. Catabolite repression by glucose and lactose requirement as an inducer for the enzyme biosynthesis, which were shown in the parent strain, was markedly diminished; instead it was found out that galactose acts as another inducer. Because pH of medium, one of the most important factors for cell growth as well as enzyme production, is closely related with the sugar concentration during culture, it was kept in the optimum range of $6.5{\sim}7.5$; for this the initial glucose concentration was adjusted to be 0.5% which was thereafter maintained by the controlled pumping-in of lactose using the pH-stat technique. By doing so, we were able to increase the productivity of ${\beta}-galactosidase$ with high transgalactosylation activity up to $44\;unit/m{\ell}-broth$.

• Microbiology and Biotechnology Letters
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• v.19 no.3
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• pp.272-280
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• 1991

The effect of media feeding rate on cell growth and monoclonal antibody production in the fed-batch culture ot hybridoma A4W was studied. In the batch culture, the highest specific antibody production rate was observed at the begining of the culture period but its value tended to decrease rapidly with the culture time. The final antibody concentration and volumetric productivity was 65 $\mu g$/ml and 13 mg Mab/l/day, respectively. In the fed-batch culture, the specific antibody production rate, $q_p$ rebounded sharply within a few hours after the media feeding was started and it remained high until the end of culture if the media feeding was continued. The final antibody concentration was 220 $\mu g$/ml and the volumetric productivity was 45.1 mg/l/day. Further increase in final antibody concentration was achieved by applying a modified media of which component was fortified with glucose and glutamine, hence the final antibody concentration in this case was 270 $\mu g$/ml and the volumetric productivity was 51.8 mg/lday, which is as four tinlcs as high cuixparinf! to that of batch culture.

• Microbiology and Biotechnology Letters
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• v.27 no.1
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• pp.46-53
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• 1999

The purpose of this study was to optimize the conditions of continuous mixed culture of C.butyricum and R. spaeroides K-7, which were able to produce hydrogen using biomass-dreived substrate. To investigate the possibility of continuous culture, semi-continuous culture was carried out for 20 days. In semi-continuous culture using the reactor system, the replacement rate of fresh medium was 30% of total medium volume for the highest hydrogen evolution. In continuous culture, the optimum dilution rate was determined to be 0.05$h^{-1}$. The continuous culture produced 3.1 times as compared with the hydrogen on batch culture. On the other hand, the continuous mixed culture produced 1.3~2.1 times as much as hydrogen of the continuous monoculture of C. butyricum. When 10g of glucose in the media (1l) was supplied as a carbon source on continuous culture, mixed culture of C. butyricum and R. sphaeroides K-7 increased hydrogen evolution rate. Because considerable amount of glutamate was contained in waste water of glutamate fermentation, utilization of glutamate was examined in mixed culture. As a result of examination, production of hydorgen was slightly inhibited by high concentration of glutamate, more than 20mM, on continuous monoculture of R. sphaeroides K-7. On the other hand, both on continuous monoculture of C. butyricum and on mixed culture of C. butyricum and R. sphaeroides K-7, production of hydrogen was not inhibited by high concentration of glutamate such as 100mM. Hence this suggests that high concentration of waste water can be used as good substrate for hydrogen production on monoculture of C. butyricum and mixed culture of C. butyricum and R. sphaeroides K-7.

• 한국생물공학회:학술대회논문집
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• 2005.10a
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• pp.272-276
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• 2005

Candida tropicalis, an osmophilic strain isolated from honeycomb, produced xylitol at a maximal volumetric production rate of 3.5 g $l^{-1}$ $h^{-1}$ from an initial xylose concentration of 200 g $l^{-1}$. Even with a very high xylose concentration, e.g., 350 g $l^{-1}$, this strain produced xylitol at a moderate rate of 2.07 g $l^{-1}$ $h^{-1}$. In a fed-batch fermentation of xylose and glucose, 260 g $l^{-1}$ of xylose was added, and xylitol production was 234 g $l^{-1}$ for 48 h, corresponding to a rate of 4.88 g $l^{-1}$ $h^{-1}$. To increase the xylitol production rate, cells were recycled in a submerged membrane bioreactor with suction pressure and air sparging. In cell-recycle fermentation, the average concentration of xylitol produced per recycle round, total fermentation time, volumetric production rate, and product yield for ten rounds were 180 g $l^{-1}$, 195 h, 8.5 g $l^{-1}$ $h^{-1}$, and 85%, respectively. When cell-recycle fermentation was started with the cell mass contratrated two-fold after batch fermentation and was performed for ten recycle rounds, we achieved a very high production rate of 12 g $l^{-1}$ $h^{-1}$. The production rate and total amount of xylitol produced in cell-recycle fermentation were 3.4 and 11 times higher than in batch fermentation, respectively.

• Asian-Australasian Journal of Animal Sciences
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• v.23 no.3
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• pp.312-317
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• 2010

Complete oxidation of fatty acid in the liver of ketotic cows was investigated. Serum non-esterified fatty acid (NEFA), beta-hydroxybutyric acid (BHBA) and glucose concentrations were measured using biochemical techniques. Carnitine palmitoyl transferase II (CPT II), 3-hydroxy acyl-CoA dehydrogenase (HAD) and oxaloacetic acid (OAA) concentrations in the liver were detected by ELISA. Serum glucose was lower in ketotic cows than controls (p<0.05). Serum BHBA and NEFA concentrations were higher in ketotic cows than controls (p<0.05). OAA, CPT II, and HAD contents in the liver of ketotic cows were lower than in controls (p<0.05). There were negative correlations between serum NEFA concentration and OAA, CPT II and HAD, but no correlation between serum BHBA concentration and capacity for complete oxidation of fatty acid. Overall, the capacity for complete fatty acid oxidation in the liver of ketotic cows might have been decreased. High serum NEFA concentrations may be unfavorable factors for the pathway of complete oxidation of fatty acid in the liver.

• Applied Biological Chemistry
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• v.10
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• pp.101-105
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• 1968

The effect of concentration of carbon and nitrogen sources on the sporulation and the life cycles of three strains of Zygosaccharomyces was investigated. The results are as follows: 1) The good sporulation of Zygosaccharomyces bisporus, delbruekii, and Z. steineri was obtained on solid medium containing 0 to 0.001% of nitrogen and 10 to 20% of glucose. The high content of nitrogen was detrimental to sporulation and asci were formed under 0.01% of nitrogen. 2) It is widely accepted that the life cycle of Zygosaccharomyces proceeds in the following way: Ascospore...Vegetative cells...Conjugation of vegetative cells...Sporulation...Ascopores But zygotes of Z. bisporus proceeded to vegetative cells when transfered to the suitable medium for vegetative reproduction, and then formed asci.