Rhodotorula sp. NJ298 which could produce carotenoids was isolated from Antarctic sea ice. The major carotenoid was identified as astaxanthin by Liquid Chromatography/Mass Spectrometry （LC/MS）, and its content accou...Rhodotorula sp. NJ298 which could produce carotenoids was isolated from Antarctic sea ice. The major carotenoid was identified as astaxanthin by Liquid Chromatography/Mass Spectrometry （LC/MS）, and its content accounted for 87.62% of total carotenoids （1,786 μg/g）. High Performance Liquid Chromatogrephy （HPLC） analysis showed that the purity of the astaxanthin reached about 96. 16% through a simple purification. Maximum astaxanthin production （1,908μg/g） was obtained when the yeast was grown at 10 ℃ in seawater medium containing 5 g/L sodium acetate, 5 g/L peptone, 0.5 g/L NaC1, 0.01 g/L KH2PO4; 0.01 g/L MgSO4·7H20 and 0.001 g/L FeSO4·7H20 at pH 7.5.展开更多
Previous studies demonstrated that cryptochromes are involved in blue light-induced coiling and prehaustoria development in young de-etiolated dodder seedlings. In this study, we suggest that carotenoids and chlorophy...Previous studies demonstrated that cryptochromes are involved in blue light-induced coiling and prehaustoria development in young de-etiolated dodder seedlings. In this study, we suggest that carotenoids and chlorophyll are not the blue light absorbing chromophores involved in the mediation of prehaustoria development to blue light. Norflurazon-bleached dodder segments coiled and formed prehaustoria under blue light. However, norflurazon significantly reduced prehaustoria number （62%） under a mixture of red and far-red light, suggesting that phytochromes could be altered by norflurazon.展开更多
Vitamin A deficiency still remains a nutritional concern in Cameroon. Squashes pulp is rich in provitamins A and could help to reduce this deficiency. Unfortunately, in Cameroon, squash pulp is more often reserved for...Vitamin A deficiency still remains a nutritional concern in Cameroon. Squashes pulp is rich in provitamins A and could help to reduce this deficiency. Unfortunately, in Cameroon, squash pulp is more often reserved for the nutrition of sick people and domestic animals. This study aimed at encouraging the consumption of squash pulp to contribute to vitamin A needs. The contents of a-carotene, all-trans-β-carotene and ascorbic acid were determined respectively by HPLC and titration with 2.6 dichlorophenol-indophenol in five landraces of raw, steamed, steam-dried and fried squash pulp from Cameroon. Moisture and total lipid content were also determined. Peeled pulp squash of 5 cm slice was steamed at 90℃ for 30 min or at 85℃ for 30 min, sliced again at 5 mm thickness and dried at 80℃ during 4 h to obtained steamed or steam-dried squashes. To have fried squashes, 40 g of 1 mm thickness slices pulp were fried in boiling refined palm oil （free of carotenoids） bath at 150℃ during 7 and 10 min. The results obtained showed that steam-drying and frying of squashes leaded to water losses （89%-95%）. As a consequence of this, the a-carotene, all-trans-β-carotene and ascorbic acid contents （expressed in g （100 g）-1 fresh portion） of steam-dried and fried squashes were significantly higher （P 〈 0.05） than those of steamed and raw pulp. However, the retention rate of provitamins A and ascorbic acid was more elevated in steamed than in steam-dried and fried squashes. These results suggest that steam-dried and fried squashes could contribute to fight against vitamin A deficiency while increasing availability of squashes.展开更多
Effect of fertilizer source （mineral fertilizer or organic manure） on photosynthetic pigments leaves content of four brassica vegetables （Pak choi, Kohlrabi, Cauliflower and Cabbage） was tested. Among treatments, ...Effect of fertilizer source （mineral fertilizer or organic manure） on photosynthetic pigments leaves content of four brassica vegetables （Pak choi, Kohlrabi, Cauliflower and Cabbage） was tested. Among treatments, cauliflower fertilized with chicken manure had the highest content of chlorophyll a and b （10.08 and 9.37 μm·g^-1）, while, pak choi had the lowest values （2.00 and 2.44 μm·g^-1） in non-fertilized plants. These differences in chlorophyll a and b content may have a great impact on photosynthetic rate and activity. Total carotenoids and total xanthophylls （lutein, zeaxanthin, antheraxanthin and violaxanthin） were the highest in cauliflower while the lowest was in pakchoi, β-carotene, on the other hand, was the highest percentage of total carotenoids （65.7%） in pak choi while Kohlrabi had the lowest percent （57.4%）. This high percentage offl-carotene of total carotenoids may compensate for lower content of chlorophylls and assist for efficient light harvesting process. Lutein showed to be the major components of xanthophyll pigments brassica vegetables and ranged from 0.462μm·g^-1 in cabbage to 0.626μm·g^-1 in kohlrabi but not differed significantly which may refer to genetically controlled. However, lutein, antheraxanthin and zeaxanthin content were increased significantly by the application of chicken manure regardless ofbrassica vegetable type. Violaxanthin was only detected in pak choi and not affected by fertilizer source. It can be concluding from the increasing contents of total xanthophylls pigments that may increase photosynthetic efficiency through non-photochemical quenching process.展开更多
基金Supported by the National Natural Science Foundation of China （No. 40406003 and 40206022）.
文摘Rhodotorula sp. NJ298 which could produce carotenoids was isolated from Antarctic sea ice. The major carotenoid was identified as astaxanthin by Liquid Chromatography/Mass Spectrometry （LC/MS）, and its content accounted for 87.62% of total carotenoids （1,786 μg/g）. High Performance Liquid Chromatogrephy （HPLC） analysis showed that the purity of the astaxanthin reached about 96. 16% through a simple purification. Maximum astaxanthin production （1,908μg/g） was obtained when the yeast was grown at 10 ℃ in seawater medium containing 5 g/L sodium acetate, 5 g/L peptone, 0.5 g/L NaC1, 0.01 g/L KH2PO4; 0.01 g/L MgSO4·7H20 and 0.001 g/L FeSO4·7H20 at pH 7.5.
文摘Previous studies demonstrated that cryptochromes are involved in blue light-induced coiling and prehaustoria development in young de-etiolated dodder seedlings. In this study, we suggest that carotenoids and chlorophyll are not the blue light absorbing chromophores involved in the mediation of prehaustoria development to blue light. Norflurazon-bleached dodder segments coiled and formed prehaustoria under blue light. However, norflurazon significantly reduced prehaustoria number （62%） under a mixture of red and far-red light, suggesting that phytochromes could be altered by norflurazon.
文摘Vitamin A deficiency still remains a nutritional concern in Cameroon. Squashes pulp is rich in provitamins A and could help to reduce this deficiency. Unfortunately, in Cameroon, squash pulp is more often reserved for the nutrition of sick people and domestic animals. This study aimed at encouraging the consumption of squash pulp to contribute to vitamin A needs. The contents of a-carotene, all-trans-β-carotene and ascorbic acid were determined respectively by HPLC and titration with 2.6 dichlorophenol-indophenol in five landraces of raw, steamed, steam-dried and fried squash pulp from Cameroon. Moisture and total lipid content were also determined. Peeled pulp squash of 5 cm slice was steamed at 90℃ for 30 min or at 85℃ for 30 min, sliced again at 5 mm thickness and dried at 80℃ during 4 h to obtained steamed or steam-dried squashes. To have fried squashes, 40 g of 1 mm thickness slices pulp were fried in boiling refined palm oil （free of carotenoids） bath at 150℃ during 7 and 10 min. The results obtained showed that steam-drying and frying of squashes leaded to water losses （89%-95%）. As a consequence of this, the a-carotene, all-trans-β-carotene and ascorbic acid contents （expressed in g （100 g）-1 fresh portion） of steam-dried and fried squashes were significantly higher （P 〈 0.05） than those of steamed and raw pulp. However, the retention rate of provitamins A and ascorbic acid was more elevated in steamed than in steam-dried and fried squashes. These results suggest that steam-dried and fried squashes could contribute to fight against vitamin A deficiency while increasing availability of squashes.
文摘Effect of fertilizer source （mineral fertilizer or organic manure） on photosynthetic pigments leaves content of four brassica vegetables （Pak choi, Kohlrabi, Cauliflower and Cabbage） was tested. Among treatments, cauliflower fertilized with chicken manure had the highest content of chlorophyll a and b （10.08 and 9.37 μm·g^-1）, while, pak choi had the lowest values （2.00 and 2.44 μm·g^-1） in non-fertilized plants. These differences in chlorophyll a and b content may have a great impact on photosynthetic rate and activity. Total carotenoids and total xanthophylls （lutein, zeaxanthin, antheraxanthin and violaxanthin） were the highest in cauliflower while the lowest was in pakchoi, β-carotene, on the other hand, was the highest percentage of total carotenoids （65.7%） in pak choi while Kohlrabi had the lowest percent （57.4%）. This high percentage offl-carotene of total carotenoids may compensate for lower content of chlorophylls and assist for efficient light harvesting process. Lutein showed to be the major components of xanthophyll pigments brassica vegetables and ranged from 0.462μm·g^-1 in cabbage to 0.626μm·g^-1 in kohlrabi but not differed significantly which may refer to genetically controlled. However, lutein, antheraxanthin and zeaxanthin content were increased significantly by the application of chicken manure regardless ofbrassica vegetable type. Violaxanthin was only detected in pak choi and not affected by fertilizer source. It can be concluding from the increasing contents of total xanthophylls pigments that may increase photosynthetic efficiency through non-photochemical quenching process.
