• 대한수의학회지
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• 제36권2호
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• pp.463-470
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• 1996

The red yeast Phaffia rhodozyma, which contains astaxanthin(3, 3'-dihydroxy-$\beta$, $\beta$-carotene-4, 4'-dione) as its primary carotenoid, was tested as a dietary pigment source for egg yolks of laying hens. When the yeast was fed to laying hens at several concentrations, the intensity of redness in egg yolks was dependent on the yeast concentration in the feed and the deposition period. Addition of P rhodozyma in feed did not cause any visible adverse effect on laying hens.

• Journal of Microbiology and Biotechnology
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• 제6권2호
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• pp.103-109
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• 1996

Mn(II)+succinate decreased the carotenoid formation of the yeast Phaffia rhodozyma, probably by scavenging $O_2$. When duroquinone (DQ), an internal and external $O_2$ generator, was added to medium, P. rhodozyma produced more amount of carotenoids. The increased carotenoid production was destroyed by oxygen radical (OR) scavengers, ascorbate+Cu(II) and dimethylsulfoxide. When sub-lethal concentrations of $H_2O_2$ , an external OR source, and antimycin, an internal OR inducer, were used, the effect of $H_2O_2$ on carotenoid formation and composition was less significant than that of antimycin. Addition of superoxide dismutase, an external OR remover, rescued cells from death caused by the high concentration of DO. In this condition, the yeast culture showed an increase in carotenoid content. Addition of DQ into P. rhodozyma culture in the stationary phase did not increase carotenoid production. Therefore, carotenoid formation was stimulated by internal ORs in the growing yeast. It was probably due to release of catabolite repression on carotenogenesis in the yeast. Aeration was important for carotenoid production but was not as effective as the internal OR producer, DQ.

• Journal of Microbiology and Biotechnology
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• 제6권2호
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• pp.110-115
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• 1996

Yellow mutants of the astaxanthin producing red yeast Phaffia rhodozyma were obtained by nitrosoguanidine mutagenesis. The carotenoid composition of the yelow mutants, Yan-1 and Ny-1, was mainly $\beta$ -carotene (> 95$%$) and torulene (< 5$$). Therefore, the yellow mutants are carotene oxygenation deficient mutants (CODMs). CODMs produced decreased quantities of carotenoids compared to their red parents and this indicated that carotene may regulate its synthesis. CODMs, Yan-1 and Ny-4, on plates containing 50 $\mu$ M antimycin, showed highly pigmented vertical papillae. Antimycin-induced mutants purified from the papillae showed increases in carotenoid content (up to 1 mg $\beta$-carotene/g yeast). CODMs, Yan-1 and Ay-1, were more sensitive to antimycin than red strains, Ant-1 and 67-385. This was probably due to lower antioxidant activity of $\beta$-carotene than that of astaxanthin. Light increased torulene and light+antimycin further increased the torulene. Yan-1 and Ny-4 could grow with succinate, though their red parents, Ant-1 and Anf-1p, could not. However, antimycin induced mutation of Yan-1 or Ny-4 destroyed the ability to grow with succinate.

• Journal of Microbiology and Biotechnology
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• 제2권1호
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• pp.46-49
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• 1992

The availability of Phaffia rhodozyma as an astaxanthin sources in the aquaculture industry is limited because of the low carotenoid content of natural isolate. In this study, we have used the protoplast fusion technique to construct cell hybrids with an increased content of astaxanthin from P. rhodozyma. Cell hybrids (F307 and F406) obtained were very stable and produced considerably more astaxanthin (> 1 mg/g yeast) than the wild parent. Karyogamy was confirmed by the isolation of recombinants after mitotic segregation of parental auxotrophic genetic markers, the increased amount of chromosomal DNA/cell and the presence of single nucleus/cell.

• KSBB Journal
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• 제17권2호
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• pp.176-181
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• 2002

Astaxanthin (3,3＇-dihydroxy-${\beta}$, ${\beta}$-carotene-4-4＇-dione), a natural pigment of pink to red color, is widely distributed in nature particularly in the skin layer of salmonoids and the crust of shrimp, lobster, etc. Recently, it was produced from the yeast culture of Phaffia rhodozyma. Because of its high thermal stability and antioxidant functionality, its applications can be extended into food, cosmetics, and pharmaceutical ingredient beyond the traditional feed additive. Because of its very high lipophilicity, astaxanthin has been extracted traditionally by strong organic solvents such as chloroform, petroleum ether, acetone, etc. In this study, we developed a surfactant-based solubillization system for astaxanthin, and used it to extract astaxanthin from disrupted yeast cells. Among Tween 20, Triton X-100 and SDS, Tween 20 was identified as the most suitable surfactant in terms of extraction capacity and safety. The ethylene oxide group of Tween 20 was identified as the most significant factor to increase the HLB value that determined the extraction capacity. The effects of micelle formation condition, such as the molar ratio of astaxanthin and Tween 20, pH, and ionic strength were also investigated. pH and ionic strength showed no significant effects. The optimal molar ratio between astaxanthin and Tween 20 was 1 : 12. Antioxidant activity of astaxanthin was higher than ${\beta}$-carotene and ${\alpha}$-tocopherol. Astaxanthin in the crude extract from the yeast cell was more resistant to air and/or light degradation than pure astaxanthin, probably because of the presence of other carotenoids and lipids.

• 한국양식학회지
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• 제9권4호
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• pp.363-375
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• 1996

천연 astaxanthin 색소를 다량 함유한 phaffia 효모를 양식 어류에게 공급하였을 때, 이 색소가 어류의 성장과 소화, 흡수되는 정도를 조사하기 위하여 이스라엘 잉어($650{\pm}20$ g), 비단잉어($80{\pm}10$ g) 및 나일틸라피아($200{\pm}20$ g)의 사료에 phaffia 효모를 $10\%$ 첨가하여 10주간 공급한 다음 성장률, 체조성, 근육의 탄력도 및 근육 색과 체색 등의 변화를 측정하였다. Phaffia 효모 첨가 사료에 대한 효모 대조구로서 $10\%$의 맥주 효모 첨가 사료구를, 그리고 이들 두가지 반정제 효모 사료에 대한 성장 대조구로서 시판 상품 사료구를 설정하여 10주간 사육한 결과 이스라엘 잉어, 비단잉어 및 틸라피아의 성장에는 모든 사료 공급구에서 유의적인 차이가 없었다(P>0.05). 이들 실험어의 근육 내의 일반 성분은 실험 후에도 현저한 차이가 나타나지 않아(P>0.05), phaffia 효모나 맥주 효모 사료가 체성분 조성에는 영향이 없는 것으로 나타났다. 또한 횟감으로 이용되는 어종인 이스라엘 잉어와 틸라피아의 근육에 쫄깃한 정도를 나타내는 기계적 탄력도와 관능적 탄력도를 측정한 결과 모두 유의적인 차이는 나타나지 않았다(P>0.05). 실험어의 근육에 phaffia 효모에서 유래되는 붉은 색소의 침착은 이스라엘 잉어와 비단잉어 실험구에서는 근육내의 색소 분석과 관능적 측정 실험 모두에서 현저하게 높게 나타났지만(P<0.05), 틸라피아에서는 색소 분석과 관능적 측정 실험 모두에서 유의적인 차이가 나타나지 않았다(P>0.05).

• 한국식품과학회지
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• 제31권3호
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• pp.720-726
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• 1999

고전압 펄스 전기장(PEF)가 P. rhodozyma 세포의 형태학적 변화와 carotenoid의 추출에 미치는 영향을 연구하였다. 전기장 세기 $10{\sim}50\;kV/cm$와 처리시간 $100{\sim}300\;{\mu}s$의 범위에서 세포를 PEF 처리했을 때 전기장의 세기와 처리시간이 증가함에 따라 세포의 팽창, 손상 정도와 세포내 물질이 유출되는 정도가 증가하였다. $10{\sim}50\;kV/cm$, 100 Hz의 exponential decay파로 세포현탁액을 $100\;{\mu}s$ 또는 $300\;{\mu}s$ 처리하였을 때 최대 전기장(50 kV/cm)에서 생균수가 각각 1.5 및 2.5 log 감소하였다. 50 kV/cm의 전기장에서 세포막에 형성되는 electroporation 정도는 98%에 달하였고, 이 때 세포의 회복률은 5% 미만으로 확인되었다. Phloxine B 색소로 세포를 염색했을 때 생균세포는 염색되지 않았으나, PEF 처리한 세포는 색소가 내부로 침투되어 적색으로 염색되었으므로 세포막이 손상된 것을 알 수 있었다. Carotenoid 색소가 P. rhodozyma 세포막의 지방체와 결합한 상태로 존재하기 때문에 고전압 PEF 처리에 의한 세포막 투과성 증진의 효과만으로는 색소 추출이 어려웠으나, 세포현탁액 조제시에 0.01% NaCl 용액 대신에 0.01% $CaCl_2$ 용액을 사용하는 경우에는 $10{\sim}20\;{\mu}g$의 색소 추출 증진 효과가 있었다.

• KSBB Journal
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• 제5권3호
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• pp.255-261
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• 1990

Astaxanthin을 생산하는 효모 Phaffia rhodozyma로부터 제조된 상보적 돌연변이 균주간의 세포융합을 통하여 astaxanthin을 대량 생산하는 균주를 얻고자 시도하였다. 이들의 원형질체 융합빈도는 $1.3$\times$10^-^5-6.0$\times$10^-^5$이었고 DNA함량, 핵염색, UV조사에 대한 생존력 비교 그리고 형질분리분석등으로 핵융합을 확인하였다. 융합체 중 F1은 야생형의 모 균주와 비교했을때 astaxanthin생성량이 약 3배 증가하였다.

• 한국균학회지
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• 제21권1호
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• pp.9-15
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• 1993

Astaxanthin을 생산하는 효모 Phaffia rhodozyma로 부터 제조된 상보적 돌연변이 균주사이의 융합체에 대한 carotenoid 함량 및 성분을 분석하였으며, 몇가지 화학첨가물에 의한 이들의 색소 증진 효과를 조사하였다. 핵 융합이 확인된 융합체들은 완전배지에서 1년 또는 그 이상 계대 후에도 매우 안정 하였다. 그리고 이들의 astaxanthin 함량은 야생형 모균주의 그것에 비해 약 $2.0{\sim}3.0$배 이었다. 또한 화학첨가물(malt extract, abscisic acid, gibberellic acid, riboflavin)에 의한 색소 증진 효과는 l% malt extract와 1 mM abscisic acid 첨가시 대조구에 비교해 총 caretenoid 함량이 35%와 11%가 각각 증진되었고, 이와 반대로 5 mM gibberellic acid와 0.1 mM riboflavin첨가시 19%와 12%가 각각 감소되었다.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2000년도 춘계학술발표대회
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• pp.271-274
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• 2000

A study was carried out to select a nitrogen source and the optimize the C/N ratio for the maximum cell growth of Phaffia rhodozyma in fed-batch culture. The yeast extract was the best organic nitrogen source. In the batch culture experiments, the highest cell yield was obtained 0.575 g-cell/g-glucose from 10 g/L and 10 g/L yeast extract. In the fed-batch experiments, the maximum cell concentration was obtained 33.1 g/L from the C/N ratio of 2:1 while the astaxanthin concentration of cell was Increased by increasing the C/N ratio, of feed medium.