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Publications (4)8.65 Total impact

  • Toshiki Uji · Daisuke Nanaumi · Chikara Kawagoe · Naotsune Saga · Kazuo Miyashita ·
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    ABSTRACT: A high frequency of callus induction and propagation from leaf explants of the brown alga Sargassum horneri was achieved within 2 months of culture when grown in medium supplemented with 5 μM uniconazole, which is a triazole-type inhibitor of cytochrome P450 enzymes. Adventitious buds were efficiently formed from the pigmented callus after transfer to medium without uniconazole, indicating that treatment with uniconazole was more beneficial for regeneration of the alga. Favorable culture conditions for induction of adventitious buds and calli included temperatures of 15 to 25 °C and light levels of 20 to 200 μmol photons m−2 s−1. Blue light promoted the production of adventitious buds and calli. The frequency of formation of adventitious buds and calli in explants from thalli with one leaf was more than 90 %, while it was 10 % only when explants were sourced from thalli with 9 to 11 leaves. These findings will be useful for clonal propagation and storage of seed materials for mariculture of Sargassum species.
    Journal of Applied Phycology 11/2015; DOI:10.1007/s10811-015-0745-8 · 2.56 Impact Factor
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    ABSTRACT: The present study describes the seasonal changes in lipid components of two brown algae, Sargassum horneri (Turner) and Cystoseira hakodatensis (Yendo), with specific reference to fucoxanthin (Fx) and n-3 (omega-3) polyunsaturated fatty acids (PUFAs). Young thalli of S. horneri were collected from different places, Nesaki and Matsushima, and cultivated in the same place. Total lipids (TL) and Fx contents of S. horneri increased from October or November and reached a maximum in January and then decreased thereafter. TL and Fx of S. horneri originated from Matsushima were always higher than those originated from Nesaki, suggesting that genetic variation might be a reason for the different TL and Fx contents found in both S. horneri seeds from different origin. Similar seasonal variation in the TL and Fx content has been more clearly observed in C. hakodatensis. Maximum TL content of S. horneri and C. hakodatensis reached to more than 14 and 15 % in winter season. These values were much higher than those found in previous studies showing TL content range from 1 to 5 %. Fatty acid composition of lipids from S. horneri and C. hakodatensis also changed seasonally. Total monounsaturated fatty acids showed the lower values from January to April, while there were no big variations in total saturated fatty acids and total n-6 PUFAs. On the other hand, total n-3 PUFAs became highest in winter. Overall, S. horneri and C. hakodatensis harvested from winter to spring will be used as good n-3 PUFA source with high levels of TL and Fx.
    Journal of Applied Phycology 08/2013; 25(4). DOI:10.1007/s10811-012-9934-x · 2.56 Impact Factor
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    ABSTRACT: An improved multi-step gradient reverse phase high performance liquid chromatography (HPLC) method to simultaneously separate major carotenoids from natural as well as food samples was developed. Quantitative profiling of carotenoid compounds was carried out on three edible brown seaweeds (Sargassum horneri, Cystoseira hakodatensis, and Undaria pinnatifida) and three red seaweeds (Gracilaria vermiculophylla, Grateloupia asiatica, and Grateloupia livida). Fucoxanthin (Fx) was detected in all the brown seaweeds with quantities (mg·g dry weight [dwt]) ranging from 1.3±0.3 in C. hakodatensis to 2.4±0.1 in S. horneri. U. pinnatifida, commonly known as Wakame, had a fucoxanthin content of 2.3±0.1 mg·g dwt. In the case of red seaweeds, zeaxanthin (Zx) was the major carotenoid, and G. vermiculophylla had the highest Zx content (80.2 μg·g dwt) among the red seaweeds apart from small amounts of Fx (9.1 μg·g dwt). Similarly, the other two species of red seaweeds, G. asiatica and G. livida, contained (μg·g dwt) lutein (Lut), Fx, and Zx as the major carotenoids (G. asiatica: Lut 10.4, Fx 1.5, Zx 1.1; G. livida: Lut 9.3, Fx 3.5, Zx 1.0). The results suggest the usefulness of edible varieties (barring wakame) of seaweeds as dietary sources of carotenoids.
    Journal of Aquatic Food Product Technology 10/2012; 21(5). DOI:10.1080/10498850.2011.610025 · 0.69 Impact Factor
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    ABSTRACT: Fucoxanthin (Fx) and fucosterol (Fs) are characteristic lipid components of brown seaweeds that afford several health benefits to humans. This article describes the quantitative evaluation of lipids of 15 species of brown seaweeds with specific reference to Fx, Fs, and functional long-chain omega-6/omega-3 polyunsaturated fatty acids (PUFAs). In addition, fatty-acid composition of selected species was also accomplished in the study. Major omega-3 PUFAs in the brown seaweeds analyzed were α-linolenic acid (18:3n-3), octadecatetraenoic acid (18:4n-3), arachidonic acid (20:4n-6), and eicosapentaenoic acid (20:5n-3). Both Fx (mg · g−1 dry weight [dwt]) and Fs (mg · g−1 dwt) were determined to be relatively abundant in Sargassum horneri (Turner) C. Agardh (Fx, 3.7 ± 1.6; Fs, 13.4 ± 4.4) and Cystoseira hakodatensis (Yendo) Fensholt (Fx, 2.4 ± 0.9; Fs, 8.9 ± 2.0), as compared with other brown seaweed species. Studies related to seasonal variation in Fx, Fs, and total lipids of six brown algae [S. horneri, C. hakodatensis, Sargassum fusiforme (Harv.) Setch., Sargassum thunbergii (Mertens ex Roth) Kuntze, Analipus japonicus (Harv.) M. J. Wynne, and Melanosiphon intestinalis (D. A. Saunders) M. J. Wynne] indicated that these functional lipid components reached maximum during the period between January and March. The functional lipid components present in these seaweeds have the potential for application as nutraceuticals and novel functional ingredients after their recovery.
    Journal of Phycology 07/2009; 45(4):974 - 980. DOI:10.1111/j.1529-8817.2009.00706.x · 2.84 Impact Factor