• Journal of the Korean Society of Food Science and Nutrition
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• v.40 no.5
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• pp.619-624
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• 2011

Tea extract (TE) has been shown to have anti-tumor properties in a wide variety of experimental systems. We evaluated green tea extract (GTE) as a biochemical modulator for the antitumor activity of cisplatin and doxorubicin in the treatment of human lung cancer A549 cells. Cells were grown in RPMI-1640 medium supplemented with 10% (v/v) heat-inactivated fetal bovine serum and two antibiotics (100 units/mL penicillin and $100\;{\mu}g$/mL streptomycin). Two types of TE, epigallocatechin galate (EGCG) and GTE, were used in this experiment. The cells were seeded at $1{\times}10^4$ cells/well in the RPMI-1640 media with or without TE ($100\;{\mu}g$/mL) and then treated with different concentrations of doxorubicin ($0{\sim}14\;{\mu}g$/mL) or cisplatin ($0{\sim}35\;{\mu}g$/mL). After incubation in 5% $CO_2$ at $37^{\circ}C$ for 24 hr, cell viability was determined with a MTT assay. We used a Western blot to detect the influence of EGCG and GTE on the expression of p53 and caspase-3 genes in the A549 cells. A549 cell viability decreased to 15% with a $10\;{\mu}g$/mL concentration of cisplatin, and to 21% with a $8\;{\mu}g$/mL concentration of doxorubicin, as measured with the MTT assay. However, pre-treatment of the cells with EGCG ($100\;{\mu}g$/mL) or GTE ($100\;{\mu}g$/mL) resulted in decreased cell viability with $6\;{\mu}g$/mL of cisplatin and $4\;{\mu}g$/mL of doxorubicin. There was no apparent change in cell viability between EGCG or GTE administration in cisplatin- or doxorubicin-induced cytotoxicity in A549 cells. The levels of p53 and caspase-3 in the A549 cells increased with both EGCG and GTE treatment. We found that GTE could potentially affect cisplatin- or doxorubicin-induced cytotoxicity of A549 cells, which may be useful in the chemotreatment of cancer.

• Korean Journal of Environmental Agriculture
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• v.17 no.1
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• pp.34-38
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• 1998

To test a potential salt tolerance in phosphorus (P) efficient plants (T9 and T8), tomato seedlings were hydroponically grown in saline media. The tolerance was evaluated by comparing growth and metabolism against T5, non-P-efficient variety, at different salt concentrations: 0, 1, 5, 10 g/L. Fresh weights (FW) were measured weekly. Dry weight (DW), mineral contents, and stomatal resistance (Rs) were measured at the termination of experiment. At the lower two salt concentrations (0, 1 g/L), no significant difference was observed in terms of FW, DW, and Rs. At 5, 10 g/L of salt concentration, however, significant variation is evident: T9 and T8 outperformed T5. On the other hand, no difference was also in N, P, K, and Na contents at the corresponding salt concentration. These observations together indicate that P-efficient strain can better tolerate to salinity.

• KSBB Journal
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• v.7 no.4
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• pp.247-251
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• 1992

The effect of biomass concentration of Saccharomyces cerevisiae ATCC 24858 on specific growth rates, biomass yields, ethanol yields and productivity in the batch fermentation of rotary shaker was investigated. The specific growth rate decreased according to the increase in the biomass density and finally became zero at a biomass concentration, 55g/L. The ethanol yield $Y_{p/s}$ represented a constant value, 0.43, regardless of the change of biomass concentrations. However, the biomass yield $Y_{x/s}$ showed a trend to diminish in values with augmentation of biomass density and ultimately to reach zero at 55g/L of biomass concentration. The ethanol productivity increased linearly with biomass concentration so that, in case of initial sugar concentration, 170g/L, the productivity for 55g/L of biomass density rose up to 30g/L$\cdot$hr for all the batch fermentations. And also the ethanol concentration inhibiting completely the growth was verified 95g/L by applying experimental data to Luong's equation.

• Microbiology and Biotechnology Letters
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• v.43 no.2
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• pp.164-168
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• 2015

Citric acid is produced via submerged fermentation using yeasts. Among eight different strains of yeast, Candida zeylanoides was chosen as the strain for producing citric acid and optimized for various C/N ratios and effects of phosphate or Fe²⁺ ions in a clean carbon source medium (glucose: fructose, 1:1). The yield of citric acid was maximized at a C/N ratio of 40/1, a phosphate addition of 1.0 g/l, and an Fe²⁺ ion concentration of less than 50 mg/l, yielding up to 91 g/L in the broth with 18.5 g/l of isocitric acid in a six-day fermentation period using a pre-treated molasses medium. The yield of batch culture was 0.51 (Y_p/s, g/g) in a 5 L-Jar fermenter.

• Applied Biological Chemistry
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• v.41 no.7
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• pp.496-499
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• 1998

For the production of theobromine from caffeine, 5 strains of bacteria capable of producing theobromine were isolated from soil. Among them, the strain CT-017 showed the best ability of producing theobromine, and was partially identified as a Pseudomonas sp. For the production of theobromine, fructose was the most effective carbon source at an optimum concentration of 5 g/l. The most effective nitrogen source was 5 g/l of beef extracts. And 0.02 g/l of $Fe^{2+}$, 1.0 g/l of threonine were effective for the production of theobromine. The optimum temperature and initial pH were $28^{\circ}C$ and 6.5, respectively. After 23 hr cultivation, 7.98 g/l of theobromine was produced from 15 g/l of caffeine which corresponds to a conversion yield of 53.2%.

• 한국생물공학회:학술대회논문집
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• 2002.04a
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• pp.91-94
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• 2002

Arachidonic acid is a polyunsaturated fatty acid(PUFA) containing twenty carbon atoms with four double bonds. The family of w-6 PUFA, including arachidonic acid as well as r-linoleic acid, was served as intermediates in the formation of several key prostaglandin and leukotrienes. Several fungal strains of the genus Mortierella accumulate high amounts of arachidonic acid. In this study experiments were carried out to optimize the culture conditions for the mass production of fungus Mortierella alpina DSA -12 and lipid production with high proportion of polyunsaturated fatty acids, especially arachidonic acid. The batch culture was carried out in 500 L fermenter containing 50 g/L glucose, 18 g/L corn-steep powder and 100 mg/L MnS04 under $25^{\circ}C$, aeration rate of 0.5 vvm and agitation speed of 200 rpm without pH control. As a result, we could be obtained 22 g/L of cell mass with high contents of lipid 12.1 g/L) and arachidonic acid (5.1 g/L) The intermittent fed-batch culture was performed in the medium containing 20 g/L glucose and 10 g/L corn-steep powder. The final glucose concentration was 170 g/L and pH was maintained at 5.5 ${\sim}$ 6.0 by adding 14% ammonia solution. It was shown relatively high cell concentration (70.5 g/L) with high contents of lipid (45.8 g/L) and arachidonic acid 08.3 g/L). Therefore, when compared to batch cultures, the high concentration of arachidonic acid could be obtained by fed-batch culture using M. alpina DSA -12. These results imply that the fed-batch culture of M. alpina DSA -12 was feasible in industrial purpose and could be employed in the commercial production of arachidonic acid.

• Journal of Microbiology and Biotechnology
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• v.32 no.8
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• pp.1054-1063
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• 2022

Trehalose is a non-conventional sugar with potent applications in the food, healthcare and biopharma industries. In this study, trehalose was synthesized from maltose using whole-cell Pseudomonas monteilii TBRC 1196 producing trehalose synthase (TreS) as the biocatalyst. The reaction condition was optimized using 1% Triton X-100 permeabilized cells. According to our central composite design (CCD) experiment, the optimal process was achieved at 35℃ and pH 8.0 for 24 h, resulting in the maximum trehalose yield of 51.60 g/g after 12 h using an initial cell loading of 94 g/l. Scale-up production in a lab-scale bioreactor led to the final trehalose concentration of 51.91 g/l with a yield of 51.60 g/g and productivity of 4.37 g/l/h together with 8.24 g/l glucose as a byproduct. A one-pot process integrating trehalose production and byproduct bioremoval showed 53.35% trehalose yield from 107.4 g/l after 15 h by permeabilized P. moteilii cells. The residual maltose and glucose were subsequently removed by Saccharomyces cerevisiae TBRC 12153, resulting in trehalose recovery of 99.23% with 24.85 g/l ethanol obtained as a co-product. The present work provides an integrated alternative process for trehalose production from maltose syrup in bio-industry.

• Food Science and Preservation
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• v.17 no.5
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• pp.698-705
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• 2010

Ripe fruits of Poncirus trifoliata were examined with a view to development of functional foods and physiological activities were assessed. The flavonoid compound of the sarcocarp extract (SC), at 20.39 mg/g, was the highest of all extracts studied, whereas that in fruit juice extract (FJ) was 18.72 mg/g. The total polyphenol content of pericarp ethanol (PE) and water (PW) extracts were 60.54 mg/g and 45.91 mg/g, respectively. The nitrite scavenging ability of PW (2.0 mg/mL) was 52.27% at pH 1.2. The tyrosinase inhibitory activity of PE (2.0 mg/mL) was 23.23%, but SW showed no such activity at any tested concentration. The electron donating abilities of PW, SC, and FJ were greater than 50% when tested at 0.5 mg/mL. Notably, the $IC_{50}$ of PW was 147.73 ${\mu}g$/mL. Inhibition of xanthine oxidase by PW and SE (0.5 mg/mL) were more than 90%, whereas the $IC_{50}$ of SC was 18.28 ${\mu}g$/mL. These results indicate that P. trifoliate ripe fruits may potentially serve as components of valuable new functional foods.

• Journal of the Korean Society of Food Science and Nutrition
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• v.26 no.4
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• pp.556-562
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• 1997

Depletion of nitrite by lactic acid bacteria isolated from Kimchi and the effects of pH and temperature on depletion of nitrite in Lactobacillus MRS broth were investigated. Depletion of nitrite by Lactobacillus plantarum and Lactobacillus sake was low in initial stage of growth but increased during growth at 15 and 2$0^{\circ}C$. L. plantarum and L. sake depleted than 90 and 75% of nitrite(250$\mu\textrm{g}$/$m\ell$) in 1 day of growth at 25 and 3$0^{\circ}C$, respectively, but depleted almost all of nitrite in 2 days. While the effect of Leuconostoc mesenteroides (150$\mu\textrm{g}$/$m\ell$) was lower compared to Lactobacillus(250$\mu\textrm{g}$/$m\ell$). In addition, even high concentrations(600 and 900 $\mu\textrm{g}$/$m\ell$) of nitrite was depleted at 2 days of growth by L. plantarum. pH of growing broth decreased as the increase of growth time and temperature, and depletion of nitrite in- creased as the decrease of pH of growing culture. However, pH of broth related with the decrease of depletion of nitrite at 25 and 3$0^{\circ}C$, but not at 15 and 2$0^{\circ}C$. Therefore, depletion of nitrite was greatly affected by growth temperature rather than by pH.

• Food Science and Preservation
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• v.19 no.1
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• pp.12-18
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• 2012

In this study, 0, 20, 40, 60, 80, and 100% $Ulmus$ $pumila$ L. nonglutinous and glutinous sikhe were added to $Ulmus$ $pumila$ L. extracts for 15 days at $4^{\circ}C$, and for seven days at $25^{\circ}C$, to examine the extracts' storage properties and sensory characteristics. The results are as follows: (1) On the changes of pH and acidity during storage of $Ulmus$ $pumila$ L. nonglutinous and glutinous sikhe, both of them showed lower pH values with lower additive $Ulmus$ $pumila$ L. extract contents. The pH value continuously decreased with a longer storage period, and the acidity was higher with a lower concentration of $Ulmus$ $pumila$ L. extract. (2) The total microbial cell count during storage of $Ulmus$ $pumila$ L. nonglutinous and glutinous sikhe at $4^{\circ}C$ was 4.6-5.0 log CFU/g at 0 day. The sikhe to which $Ulmus$ $pumila$ L. extract was not added increased to 8.8-9.0 log CFU/g on the seventh storage day, while the sikhye to which 80 and 100% $Ulmus$ $pumila$ L. extracts were added were 7.8 and 6.9 logCFU/g, respectively. Thus, the total cell count was lower with a higher additive content of $Ulmus$ $pumila$ L. extract. The total cell count of the sikhe to which 0-60% $Ulmus$ $pumila$ L. extracts reached the maximum value on the seventh storage day and did not show any change thereafter. The total cell count of the sikhe to which 80 and 100% $Ulmus$ $pumila$ L. extracts were added, however, reached the maximum value on the 10th to 13th storage days, thus showing that the storage period was increased by $Ulmus$ $pumila$ L. At $25^{\circ}C$, the total cell count was 4.6-5.0 log CFU/g on 0 day and continuously increased during the storage period. It had increased to 8.9-9.5 log CFU/g on the seventh storage day, and no differences were shown according to the additive content of $Ulmus$ $pumila$ L. extract. (3) On the sensory characteristics of $Ulmus$ $pumila$ L. nonglutinous and glutinous sikhe, the $Ulmus$ $pumila$ L. nonglutinous sikhe to which 20% $Ulmus$ $pumila$ L. extract was added showed the highest overall-acceptability value ($4.23{\pm}0.95$), whereas the $Ulmus$ $pumila$ L. glutinous sikhe to which 40% $Ulmus$ $pumila$ L. extract was added showed the highest overall-acceptability value ($3.95{\pm}0.95$). The sikhe to which 20 and 40% $Ulmus$ $pumila$ L. extracts were added showed significantly high taste, flavor, sweetness, and overall-preference values (p<0.05).