• Journal of Microbiology and Biotechnology
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• 제3권4호
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• pp.238-243
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• 1993

In the suspension cultures of Eschscholtzia californica, phytohormone effects showed that alkaloid production was increased by IAA treatment without kinetin in both volumetric and specific way. Kinetin, however, suppressed alkaloid accumulation. Addition of ethephon inhibited cell growth. However, it enhanced the alkaloid production significantly in both volumetric and specific way. IAA promoted alkaloid production during elicitation. The highest alkaloid accumulation was observed at 5 $\mu$ M of IAA. Ethephon also enhanced alkaloid production during elicitation. The highest alkaloid formation was observed at 460 mg/l of ethephon with elicitation. Elicitation with ethephon, however, altered cell growth and the pattern of benzophenanthridine alkaloids production.

• 한국식품영양과학회지
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• 제28권4호
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• pp.805-809
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• 1999

The growth of Lactobacillus casei in milk was enhanced by adding yams. Addition of 1% yam(raw or dry) promoted the cell growth and acid production in fermented milk. The milk containing 1% yams formed the complete curd by lactic acid fermentation at 37oC for 19hr while the milk without yams showed the incomplete curd formation. The crude mucilage extracted from a raw yam also enhanced the cell growth as well as the acid production. Addition of mucilage(0.08%) showed the similar effects with adding heat treated yam(1%). The milk fermented by adding various yams showed the high scores for sensory evaluation comparing with the milk fermented without yams. The fermenting ability of Lactobacillus acidophilus, Lactobacillus kefir and Leuconostoc mesenteroides was evaluated by adding 1% of a dry yam in milk. A dry yam also enhanced the cell growth of L. acidophilus resulting in the high acid production. The viable cell counts of L. casei, L. acidophilus and Leuc. mesenteroides except L. kefir were increased by adding 1% of a dry yam.

• 생명과학회지
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• 제10권2호
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• pp.196-201
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• 2000

The production of tetrodotoxin (TTX) using Vibrio sp. YE-101, a novel marine microorganism isolated from the intestine of pufferfish, was investigated. Culture condition was optimized for the enhanced production of TTX using response surface methodology. The experimental sets of environmental conditions including pH, temperature and NaCl concentration were designed using central composite experimental design. The optimal conditions of pH, temperature and NaCl concentration were determined to be 8.1, 29.2℃, and 2.6% (w/v) respectively. The relative growth extent could be enhanced up to 80%, and final mouse unit (MU) value of TTX was also enhanced up to 87% by response surface optimization.

• 열처리공학회지
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• 제22권4호
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• pp.223-227
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• 2009

The feasibility of plasma electrolytic polishing technology of stainless steel was examined. The results show that austenitic stainless steel can be polished clearly using potentiostatic regimes with various concentration of ammonium sulfate ($(NH_4)_2SO_4$) solution above certain initial temperature. The equipment and deposition produces for polishing process are described and the effect of processing parameters on the characterizations polished-samples has been investigated.

• Nutrition Research and Practice
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• 제1권2호
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• pp.94-99
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• 2007

The immunostimulating activities of mucilage fraction from yam were investigated. The proliferation of BSA-primed lymph node cells was enhanced between 4.1- to 10.9-fold compare to control, when cultured with 1 to $25{\mu}g/mL$ of yam-mucilage fraction. It showed strong immunostimulating activity than ginseng extract and as remarkable as Bifidobacterium adolescentis M101-4 known as a positive immunostimulator. Mitogenicity to lymph node cells was fully induced by concanavalin A and lipopolysaccharide. The proliferation of splenocytes and Peyer's patch cells was enhanced between 5.0- to 14.1-fold and 2.4- to 6.4-fold, respectively, when cultured with 1 to $25{\mu}g/mL$ of yam-mucilage fraction. It enhanced the production of cytokines such as tumor necrosis $factor-{\alpha}$ and IL-6 in the culture of RAW 264.7 macrophage cells. In the culture of lipopolysaccharide-stimulated RAW 264.7 cells, production of cytokines was as similar as compared to controls. In unstimulated RAW 264.7 cells, both tumor necrosis $factor-{\alpha}$ and IL-6 production were enhanced between 15.6- to 60.1-fold and 2.3- to 9.1-fold, respectively. Mucilage fraction from yam is expected to be a safe immunopotentiator to maintain the host immunity and develop a physiologically functional food.

• Journal of Plant Biotechnology
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• 제5권3호
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• pp.149-155
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• 2003

Metabolic engineering for production of isoflavones in nonlegume plants could distribute the health benefits of these phytoestrogens in more widely-consumed grains. Series of investigation to check the ability of the heterologous isoflavone synthase enzyme to interact with the endogenous phenylpropanoid pathway have been conducted. Overall, results provide possibility of production of isoflavonoids in several plant tissue systems including soybean and nonlegumes. In tissue that undergoes naturally enhanced synthesis of anthocyanins, genistein production was enhanced. In a monocot cell system, introduced expression of a transcription factor regulating genes of the anthocyanin pathway was effective in conferring the ability to produce genistein in the presence of the isoflavone synthase gene. However, in this case the intermediate accumulated to high levels indicating an inefficiency in its conversion. Introduction of a third gene, chalcone reductase, provided the ability to synthesize an additional substrate of isoflavone synthase resulting in production of the isoflavone daidzein. These research efforts provide insight into requirements for metabolic engineering for isoflavone production in nonlegume dicot and monocot tissues.

• Biotechnology and Bioprocess Engineering:BBE
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• 제7권3호
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• pp.171-177
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• 2002

The metabolic flux pattern for L-histidine production was analyzed when glucose and/or acetate were used as carbon sources. Total L-histidine production was enhanced when mixed substrate (glucose and acetate) was used, compared wish that when either glucose or acetate was used as the sole carbon source. Theoretical maximum carbon fluxes through the main pathways for L-histldine production, cell growth, and ATP consumption for cell maintenance were obtained by the linear programming (LP) method. By comparison of the theoretical maximum carbon fluxes tilth actual ones, it was found that a large amount of glucose was actually used for maintenance of cell viability. On the other hand, acetate was used for cell growth. After depletion of acetate in the mixed substrate culture, the flux for glucose to L-histldine synthesis was markedly enhanced. A strategy for effective L-histidine production using both carbon sources was proposed.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2003년도 생물공학의 동향(XII)
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• pp.105-108
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• 2003

To enhance the performance of a serum-free medium (SFM) for human thrombopoietin (hTPO) production in suspension cultures of recombinant Chinese hamster ovary (rCHO) cells, several low-cost hydrolysates such as yeast hydrolysate (YH), soy hydrolysate, wheat gluten hydrolysate and rice hydrolysate were tested as medium additives. Among various hydrolysates tested, the positive effect of YH on hTPO production was most significant. When 5 g/L YH was added to SFM, the maximum hTPO concentration in batch culture was 40.41 ${\mu}g/mL$, which is 11.5 times higher than that in SFM without YH supplementation. This enhanced hTPO production in YH-supplemented SFM was obtained by the combined effect of enhanced $q_{hTPO}$ and increased culture longevity. In addition YH supplementation did not affect in vivo biological activity of hTPO. Taken together, the results obtained demonstrate the potential of YH as a medium additive for hTPO production in serum-free suspension cultures of rCHO cells.

• Natural Product Sciences
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• 제2권2호
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• pp.90-95
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• 1996

When reserpine-producing cell strains of Rauwolfia serpentina were transferred from the dark to the light irradiation, the production of reserpine was extremely enhanced whereas the cell growth was suppressed. In an incubation period of 20 days, the most effective culture condition for reserpine production was the combination of 8 days of dark culture and following 12 days of light culture. The time courses of both cell growth and reserpine production were measured in vitro in order to clarify the effect of wave length range of light on the biosynthesis of reserpine. Although the growth of cultured cells which had been incubated under continuous red, yellow, and green lights, respectively, was similar to that of the cultured cells subcultured in the dark. The cells cultured under red light irradiation produced less reserpine than dark-grown cultures. Both blue and near-ultraviolet light inhibited the growth of cultured cells. The production of reserpine was strikingly enhanced by blue light, but was strongly inhibited by near-ultraviolet light.

• 한국식물생명공학회:학술대회논문집
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• 한국식물생명공학회 2003년도 식물바이오벤처 페스티발
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• pp.77-84
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• 2003

Metabolic engineering for production of isoflavones in non-legume plants could distribute the health benefits of these phytoe-strogens in more widely-consumed grains. We investigate the ability of the heterologous isoflavone synthase enzyme to interact with the endogenous phenylpropanoid pathway. Overall, results provide possibility of production of isoflavonoids in several plant tissue systems including soybean and non-legumes. In tissue that undergoes naturally enhanced synthesis of anthocyanins, genistein production was enhanced. In a monocot cell system, introduced expression of a transcription factor regulating genes of the antho-cyanin pathway was effective in conferring the ability produce genistein in the presence of the isoflavone synthase gene. However, in this case the intermediate accumulated to high levels indicating an inefficiency in its conversion. Introduction of a third gene, chalcone reductase, provided the ability to synthesize an additional substrate of isoflavone synthase resulting in production of the isoflavone daidzein. These research efforts provide insight into requirements for metabolic engineering for isoflavone production in non-legume dicot and monocot tissues.