• Biotechnology and Bioprocess Engineering:BBE
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• 제8권6호
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• pp.349-353
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• 2003

The physiological characteristics of cultures of very high cell mass (e.g. 10g cell mass/L), termed“ultrahigh cell density cultures”is reviewed. A close relationship was found between the length of the optical path (OP) in flat-plate reactors and the optimal cell density of the culture as well as its areal (g m$\^$-2/ day$\^$-1/) productivity. Cell-growth inhibition (GI) unfolds as culture density surpasses a certain threshold. If it is constantly relieved, a 1.0cm OP reactor could produce ca. 50% more than reactors with longer OP, e.g. 5 or 10cm. This unique effect, discovered by Hu et al. [3], is explained in terms of the relationships between the frequency of the light-dark cycle (L-D cycle), cells undergo in their travel between the light and dark volumes in the reactor, and the turnover time of the photosynthetic center (PC). In long OP reactors (5cm and above) the L-D cycle time may be orders of magnitude longer than the PC turnover time, resulting in a light regime in which the cells are exposed along the L-D cycle, to long, wasteful dark periods. In contrast, in reactors with an OP of ca. 1.0 cm, the L-D cycle frequency approaches the PC turnover time resulting in a significant reduction of the wasteful dark exposure time, thereby inducing a surge in photosynthetic efficiency. Presently, the major difficulty in mass cultivation of ultrahigh-density culture (UHDC) concerns cell growth inhibition in the culture, the exact nature of which is awaiting detailed investigation.

• 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.

• Mycobiology
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• 제34권2호
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• pp.83-91
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• 2006

Characteristic growth patterns of Cordyceps militaris isolates on various media, under varying light conditions and at varying incubation periods were examined. Light was found to be the most critical single factor in determining the density, texture, and pigmentation of the mycelial culture of the fungus. However, under the light condition, the degree of pigmentation and mycelial density were found to be affected by the incubation period and type of medium. Irrespective of the variations in medium type or incubation period, there was no pigmentation of the mycelium under dark condition. Radial growth of the mycelium was faster under dark incubation rather than under light incubation. Abundant mycelial density and darkest pigmentation of C. militaris isolates were produced in nutritionally rich media like SDAY, SMAY and CZYA, suggesting that these media may fulfill all the requirements for vegetative growth of the fungus. Growth characteristics of C. militaris isolates could be easily observed by the simple agar culture method, which would be useful to characterize the phenotypic characteristics of large number of pure cultures of the fungus under given conditions of growth factors such as medium, light and temperature.

• 식물조직배양학회지
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• 제21권1호
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• pp.47-53
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• 1994

본 실험은 포도와 미국자리공의 세포현탁배양계에서 세포생장과 athocyaninn 및 betacyanin 색소생성에 미치는 광의 영향을 조사하였다. 그 결과, 포도의 세포현탁배양계에서의 세포증식 패턴은 광의 효과가 미약하였으나, 미국자리공의 경우는 암배양에 비하여 광조사구에서 뚜렷한 세포증식 패턴을 나타내었다. 포도세포는 12일간의 배양기간중 한번의 생장 피크를 보여주는데 비하여 미국자리공의 배양세포는 두 번의 증식 피크를 보여 광이 세포의 생장 및 분열 주기를 촉진시킬 뿐만 아니라 색소의 축적도 촉진시키는 것으로 나타났으며, 미국자리공 배양세포는 배양 후 4일째에 액포화에 따른 색소의 축적이 확인되었다. 한편, 색소생성에 미치는 광의 영향은 포도 현탁배양계에서는 배양후 6일째부터 생성되기 시작하여 배양 후 10일 전후에 최고치를 보이는데 비하여, 미국자리공의 현탁배양계에서는 세포증식 패턴에 따라 배양 후 4일째와 8일째에 두 번의 피크를 보였다. 그러나 이들 두 가지 모두 암배양하에서는 거의 색소 생합성이 이루어지지 않고 광상태하에서만 색소의 축적을 볼 수 있었다. 한편, 포도 세포배양계에서는 배양 후 4일째에 처리한 광은 약간의 효과가 있었으나, 배양 후 7일째 12시간 이상의 광에 의하여 색소생성이 크게 촉진되는 것을 알 수 있었다. 미국자리공의 경우에는 배양 후 7일 째보다는 오히려 배양 후 4일째에 광이 더욱 효과적이었다. 이상의 사실은 이들 두 가지 색소의 생합성과정에는 광이 절대적으로 필수적이지만 광을 필요로 하는 시기 및 요구하는 광량 등이 서로 다르다는 것을 시사해 준다.

• Biotechnology and Bioprocess Engineering:BBE
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• 제8권1호
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• pp.32-36
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• 2003

Production of camptothecin ((PT) from callus cultures of Camptotheca acuminata Decne was affected by light and culture conditions. Among the culture media tested, modified B5 medium containing 3% (w/v) sucrose, 2 mg/L B,4-D, 2 times of MS medium vitamins, 500 mg/L casein hydrolysate, 250 mg/L myo-inositol, 0.05% (w/v) activated charcoal, and 0.15% (w/v) gelite was used for callus induction . The highest cell growth and CPT production were obtained in dark and green light condition, respectively. Photoperiod has no effect on cell growth and CPT production. Both cell growth and CPT production were also influenced by combination ratio of red and blue light .Cell growth and CPT production were the highest in the ratio of red and blue light,90:10.

• 식물조직배양학회지
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• 제22권2호
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• pp.65-70
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• 1995

자리공 모상근에서 betalain의 합성에는 광이 필수이지만 생장률은 암상태 보다 광상태(1500 1X)에서 5배 정도 억제된다. 따라서 광상태에서 모상근의 생장이 억제되는 원인을 규명하기 위해서 항산화제 처리에 따른 효과를 조사하였다. 항산화제(ascorbic acid, glutathione, $\alpha$-tocopherol, sodium pyrosulfate, propylgallic acid) 처리에 따른 모상근의 생장은 암상태에서 무처리보다 1.2-1.4배, 광상태에서 약 1.3-1.9배 생장이 증가되었으며, betalain 합성은 무처리보다 1.2-2.1배 향상되었다. 자리공 모상근의 성장 및 betalain 합성에서 항산화제 복합 처리에 따른 효과는 나타나지 않았다. Betalain 합성 과정에서 항산화제의 효과는 청색 파장하에서 가장 높게 나타났다. 따라서 광상태에서 자리공 모상근의 생장과 betalain 합성을 촉진시키기 위해서는 청색 파장에서 적절한 항산화제의 개발이 요구된다.

• Journal of Ginseng Research
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• 제20권3호
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• pp.318-324
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• 1996

The effects of light on the growth and ginsenosides production were examined in the hairy roots of Panax ginsen C.A. Meyer induced by Agrobacterium rhizogines A4. The 9rowth of ginseng hairy roots in 1/2MS liquid medium was significantly decreased with an increment of light intensity (1,000~7,000 lux). The growth of hairy roots under 7,000 lux condition was decreased at 17% compared to the dark condition. The production of 7 ginsenosides in hairy root was very high in 3,500 lux condition. The production of ginsenoside-Rg, and Rf increased 3.3 and, 2.4 times respectively as compared to dark condition. The growth of hairy roots was inhibited by blue light, while ginsenosides production was increased. The sucrose demands of hairy roots was examined in light condition(3,500 lux). The growth of hairy roots in 1/2MS liquid medium with various sucrose concentrations(1~4%) was high in IVp sucrose, while ginsenosides production was high in 3% sucrose condition. The growth and ginsenosides production were high when hairy roots were cultured in dark condition for 1 week and then transferred to light condition(3,500 lux) for 4 weeks. It is suggested that ginsenosides production could be accelerated by light intensity of specific wavelength in cultures of ginseng hairy roots.

• 식물조직배양학회지
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• 제22권2호
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• pp.71-76
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• 1995

자리공 모상근에서 광처리에 따른 항산화효소의 활성을 조사하였다. Catalasa superoxide dismutasae, ascorbate oxidase (AO)의 활성은 광도가 2,000 lx까지 증가할수록 감소하였으며, 특히 AO활성은 2,000 lx에서 암상태보다 92% 감소하였다. Glutathione reductase, glutathione peroxidase (GPO), ascorbate peroxidase 그리고 peroxidase의 활성도는 500 lx까지는 광도가 높아질수록 증가하였으나 그 이상의 높은 광도에서는 현저하게 감소하였다. GPO의 활성은 AO처럼 2,000 lx에서 암상태보다 85%감소하였다. 광파장에 따른 항산화효소의 활성은 청색광의 파장에서 가장 많이 억제되었으며, AO의 활성은 25%까지 감소하였다. 청색광 파장의 광도에 따른 항산화효소의 활성도는 30 lx까지는 증가하다가 200 lx에서는 암상태보다 21-71%까지 감소하는 경향을 나타내었다. AO의 활성은 청색 파장의 광도(300-200 lx)가 증가할수록 급격히 감소하여 200 lx에서는 70%까지 억제되었다. 자리공 모상근의 항산화효소 활성은 청색광 파장의 높은 광도에서 주로 생성된 유해산소 의하여 억제되고 있음을 확인하였다. 광상태하에서 모상근의 생장과 betalain 합성을 향상시키기 위해서는 모상근에서 생성되는 산화제의 효율적인 제거가 요구됨이 시사되었다.

• 한국응용곤충학회지
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• 제14권2호
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• pp.47-52
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• 1975

Helminthosporium vicotoriae and H. carbonum were grown under fluorescent plus incandescent lights, or in darkness, with several different temperature regimes. There was little or no effect of light on toxin production by H. victoriae. Light-grown cultures of H. carbonum had significantly higher titres of host-specific toxin than did dark-grown cultures. Light had no significant effect on growth of either fungus. Maximum titres of host-specific toxins from both fungi were evident at the time maximum growth was reached. Minimum pH values in Fries modified medium occurred at the time of, or slightly before maximum level of toxin was reached.

• KSBB Journal
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• 제16권6호
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• pp.568-572
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• 2001

빛은 식물에서 성장과 발달을 비롯한 다양한 생리화학적인 역할은 지닌다. 본 연구는 hGM-CSF 유전자가 도입된 형질전한 담배의 callus를 현탁배양하여 hGM-CSF를 생산할 때에 빛을 조사하는 시간에 따른 hGM-CSF의 생산에 미치는 영향을 확인하고자 실시하였다. 24시간 명배양, 18시간 명배양과 암배양을 실시하여 세포성장과 분비된 총단백질, hGM-CSF 생산량을 비교 관찰하였다. 세포의 성장은 24시간 명배양일 때 건조중량이 14.4 g/L로 가장 높았다. 분비된 총단백질의 양은 세가지 경우에서 큰 차이를 관찰할 수가 없었지만, 단위 세포당 분비된 총단백질의 양은 암배양이 다른 것에 비해 1.5배 가량 높았다. hGM-CSF의 생산은 18시간 명배양 조건이 가장 좋았으며 최대생산량이 495.5ug/L에 이르렀다. 또한 분비된 총단백질에서 hGM-CSF가 차지하는 비율은 18시간 명배양이 24시간 명배양에 비해 최대 1.8배 높았다.