• 한국미생물·생명공학회지
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• 제35권4호
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• pp.292-297
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• 2007

H. pluviails는 고광도와 질소 결핍 배지 조건에서 ketocarotenoid의 일종인 astaxanthin을 다량 축적하는 녹조류이다. 스트레스가 없는 조건에서 키운 green cell과 astaxanthin이 합성된 red cell을 HPLC를 통해 비교해 본 결과 각 색소의 양이 변화하는 것을 볼 수 있었다. 여러 ester 형태의 astaxanthin이 생합성 되고, zeaxanthin이 늘어난 반면, lutein과 ${\beta}$-carotene은 감소하였다. 또한 total chlorophyll 양이 줄어드는 대신 total carotenoid의 양이 늘어남을 보였다. H. pluvilalis에서 찾아낸 astaxanthin 생합성 경로에 있는 carotenoid hydroxylase, phytoene desaturase, isopentenyl pyrophosphate isomerase, ${\beta}$-carotene ketolase 유전자는 음성대조군인 chloroplast chlorophyll a-b binding protein와는 달리cell이 성장하기 좋은 조건의 상태보다 astaxanthin을 생합성하기 위해 고광도의 스트레스를 받았을 때 더 높은 발현양상을 보이는 것을 확인할 수 있었다.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2001년도 추계학술발표대회
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• pp.181-184
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• 2001

The biological fixation of carbon dioxide using microalgae have many advantages over chemicals and remove carbon dioxide simultaneously. A ketocarotenoid astaxanthin is hyper-accumulated in the green freshwater microalga, Haematococcus pluvialis. In the present study, the combine effects of carbon dioxide concentration and light intensity on the growth of H. pluvilais were investigated. The carbon dioxide concentration above 10% caused a severe inhibition and around 5% is optimal for growth. Adaptation to high concentration of carbon dioxide enhanced the $CO_2$ tolerance. Specific growth rate calculated differently based upon cell number or dry weight because of the distinctive life cycle patterns of H. pluvialis : small-sized motile green cell and thick cell walled red cyst cell. Based on the light dependence of H. pluvialis, internally illuminated air-lift photobioreactor was designed and operated. Gradual increase of light supply gave more active growth and more effective productivity of astaxanthin than constant light supply.

• Biotechnology and Bioprocess Engineering:BBE
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• 제8권6호
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• pp.322-330
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• 2003

The unicellular green alga Haematococcus pluvialis has recently attracted great inter-est due to its large amounts of ketocarotenoid astaxanthin, 3,3'-dihydroxy-${\beta}$,${\beta}$-carotene-4,4'-dione, widely used commercially as a source of pigment for aquaculture. In the life cycle of H. pluvialis, astaxanthin biosynthesis is associated with a remarkable morphological change from green motile vegetative cells into red immotile cyst cells as the resting stage. In recent years we have studied this morphological process from two aspects: defining conditions governing astaxanthin biosynthesis and questioning the possible function of astaxanthin in protecting algal cells against environmental stress. Astaxanthin accumulation in cysts was induced by a variety of environmental conditions of oxidative stress caused by reactive oxygen species, intense light, drought, high salinity, and high temperature. In the adaptation to stress, abscisic acid induced by reactive oxygen species, would function as a hormone in algal morphogenesis from veget ative to cyst cells. Furthermore, measurements of both in vitro and in vivo antioxidative activities of astaxanthin clearly demonstrated that tolerance to excessive reactive oxygen species is greater in astaxanthin-rich cysts than in astaxanthin-poor cysts or astaxanthin-less vegetative cells. Therefore, reactive oxygen species are involved in the regulation of both algal morph O-genesis and carotenogenesis, and the accumulated astaxanthin in cysts can function as a protective agent against oxidative stress damage. In this study, the physiological roles of astaxanthin in stress response and cell protection are reviewed.

• 대한화장품학회지
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• 제13권1호
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• pp.45-71
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• 1987

${\beta}$-Carotene has been known as an effective quenching agent of singlet oxygen and the carotenoid pigments in general are expected to protect cells against photosensitized oxidations. We are determined the quenching rate constants of several Ketocarotenoids including capsanthin, capsanthin diester, astaxanthin and fucoxanthin, and the relative quenching actiyities against singlet oxygen were compared with those of ${\beta}$-carotene and reported carotenoids. Nevertheless the ketocarotenoids exhibited lower quenching rate constants than ${\beta}$-carotene, they showed more pronounced protective activitives than ${\beta}$-carotene against photohemlysis induced by singlet oxygen. Among the ketocarotenoids investigated, fucoxanthin indicated a significant protective activity for the cell. The results suggested that. 1) 1O2 may be alikely initiator of photohemolysis, but this reaction is followed by slow dark reactions involving secondary reactive species. 2) For protection of RBC against photodynamic action with carotenoids, carotenoids having functional groups such as -C=0 and -OH groups are most efficient. This suggests that partition of carotenoids between the buck and the mombrane and/or their specific binding to membrane proteins are more critical for the photo-protection by carotenoids than is a diffusional quenching of 1O2.

• 원예과학기술지
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• 제30권2호
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• pp.107-122
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• 2012

식물에서 화색은 종자를 퍼트리기 위해 꽃가루 매개충과 초식동물을 유인하는데 매우 중요한 도구이다. 사람에게 화색은 다채로운 시각적 다양성으로 큰 심미적 가치를 지님으로써 화훼산업의 발전은 새롭고 다양한 매력을 지닌 화색을 생산하는 방향으로 꾸준히 발전되어 왔다. 카로티노이드 성분은 화색 중에서 적색, 홍색, 황색을 나타내는 천연색소로서 이러한 카로티노이드 생합성 경로는 생명공학 기술을 이용하여 화색을 변화시키려는 대사공학의 주된 대상으로 여겨져 왔다. 본 총설에서는 카로티노이드 생합성 대사관련 유전자 발현 조절에 의한 색소 표현형의 변화를 소개하고자 하며, 최근 카로티노이드의 생합성을 넘어 절단과 축적 조절이 화색 변경을 위한 대표적인 기작으로 보고됨에 따라 다양한 화색만큼이나 다양한 조절 기작에 대한 현재까지의 지식을 총 동원하여 원하는 화색을 지닌 인공적인 꽃(engineered flower)을 생산하기 위한 전략을 종합해서 제시하고자 하였다.

• Plant Biotechnology Reports
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• 제4권4호
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• pp.269-280
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• 2010

Lilium ${\times}$ formolongi was genetically engineered by Agrobacterium-mediated transformation with the plasmid pCrtZW-N8idi-crtEBIY, which contains seven enzyme genes under the regulation of the CaMV 35S promoter. In the transformants, ketocarotenoids were detected in both calli and leaves, which showed a strong orange color. In transgenic calli, the total amount of carotenoids [133.3 ${\mu}g/g$ fresh weight (FW)] was 26.1-fold higher than in wild-type calli. The chlorophyll content and photosynthetic efficiency in transgenic orange plantlets were significantly lowered; however, after several months of subculture, they had turned into plantlets with green leaves that showed significant increases in chlorophyll and photosynthetic efficiency. The total carotenoid contents in leaves of transgenic orange and green plantlets were quantified at 102.9 and 135.2 ${\mu}g/g$ FW, respectively, corresponding to 5.6- and 7.4-fold increases over the levels in the wild-type. Ketocarotenoids such as echinenone, canthaxanthin, 3'-hydroxyechinenone, 3-hydroxyechinenone, and astaxanthin were detected in both transgenic calli and orange leaves. A significant change in the type and composition of ketocarotenoids was observed during the transition from orange transgenic plantlets to green plantlets. Although 3'-hydroxyechinenone, 3-hydroxyechinenone, astaxanthin, and adonirubin were absent, and echinenone and canthaxanthin were present at lower levels, interestingly, the upregulation of carotenoid biosynthesis led to an increase in the total carotenoid concentration (+31.4%) in leaves of the transgenic green plantlets.