Papers - SUZUKI Yoshihiro
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Photoreduction of manganese dioxide in seawater by organic substances under ultraviolet or sunlight Reviewed
K. Matsunaga, T. Ohyama, K. Kuma, I. Kudo, Y. Suzuki
Water Research 29 ( 2 ) 757 - 759 1995.2
Language：English Publishing type：Research paper (scientific journal)
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Suzuki Y., Kuma K., Kudo I., Matsunaga K.
Phycologia 34 ( 3 ) 201 - 205 1995
Language：Japanese Publishing type：Research paper (scientific journal) Publisher：Phycologia
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Diffusion of Fe(II) from iron propagation cage and its effect on tissue iron and pigments of macroalgae on the cage Reviewed
K. Matsunaga, Y. Suzuki, K. Kuma, I. Kudo
Journal of AppliedPhycology 6 ( 4 ) 397 - 403 1994.8
Language：English Publishing type：Research paper (scientific journal)
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Effect of iron on oogonium formation, growth rate and pigments synthesis of Laminaria japonica Reviewed
Y. Suzuki, K. Kuma, K. Matsunaga
Fisheries Science 60 ( 4 ) 373 - 378 1994.4
Language：English Publishing type：Research paper (scientific journal)
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Suzuki Y., Kuma K., Matsunaga K.
Fisheries Science 60 ( 4 ) 373 - 378 1994
Language：Japanese Publishing type：Research paper (scientific journal) Publisher：Fisheries Science
The effects of iron on oogonium formation of female gametophytes, growth rate and pigment syntheses of Laminaria japonica Areschoug were investigated and compared in both soluble EDTA chelated iron (Fe(III)-EDTA) and solid amorphous hydrous ferric oxide (am-Fe(III)) media containing nitrate and phosphate. Soluble Fe(III)-EDTA [0.4-2 μM] and solid am-Fe(III) [2 μM] were found to strongly affect the oogonium formation of female gametophytes; most gametophytes in iron-free and reduced iron concentration media ( < 0.4μM in Fe(III)-EDTA, < 2μM in am-Fe(III)) continued only vegetative growth without oogonium formation. The growth rate and chlorophyll-a (Chl-a) concentration of young sporophytes significantly increased with increased iron concentration in the culture media. The growth rate and Chl-a concentration of young sporophytes cultured in am-Fe(III) media were approximately one half lower than those in Fe(III)-EDTA media, possibly as a result of the lower iron uptake rate of young sporophytes observed in am-Fe(III) media. This lower iron uptake rate may be attributed to the low solubility and the slow dissolution rate reported for solid amorphous hydrous ferric oxide in seawater. Furthermore, iron was found to promote the syntheses of fucoxanthin, chlorophyll-c, β-carotene and Chl-a in adult sporophytes. This study clearly indicates that iron plays an important role in the oogonium formation, growth rate and pigment syntheses of L. japonica. © 1994, The Japanese Society of Fisheries Science. All rights reserved.
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Solubility and dissolution rate of colloidal γ-FeOOH in seawater
Kuma K., Suzuki Y., Matsunaga K.
Water Research 27 ( 4 ) 651 - 657 1993.4
Language：Japanese Publishing type：Research paper (scientific journal) Publisher：Water Research
Solubilities and dissolution rates of colloidal γ-FeOOH (lepidocrocite), one of the typical iron oxyhydroxides, in seawater over a pH range 5.5-8.2 at 20°C were experimentally determined by dialysis techniques involving γ-activity measurements of 59 Fe. The Fe(III) dissolution rate was closely in proportion to the concentration of particulate Fe(III) in seawater and was defined as a first-order reaction. The solubilities and dissolution rate constants within the pH range 7.0-8.2 were independent of pH with values of approx. 1 × 10 -9 mol l -1 and 0.005 day -1 , respectively. This result probably indicates the existence of Fe(OH) 3 o as well as Fe(OH) 2 + in the normal pH range of seawater. The solubility and dissolution rate constants were one order of magnitude and one-third, respectively, lower than those of amorphous hydrous ferric oxide determined in a previous study. The Fe(III) dissolution rate of colloidal γ-FeOOH at the normal pH of seawater can be estimated from 0.005 × [Fe(III)particulate] (conc. day -1 ) by the concentration of particulate Fe(III) as γ-FeOOH in seawater. At lower pHs of 5.5-7.0, the logarithmic solubilities and dissolution rate constants increased linearly with decreasing pH with a slope of -1.0 and -0.95, respectively, indicating that Fe(OH) 2 + is the dominant dissolved ferric species. © 1993.
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Solubility and dissolution rate of colloidal r-FeOOH in seawater Reviewed
K. Kuma, S. Y. Suzuki, K. Matsunaga
Water Research 27 ( 4 ) 651 - 657 1992.11
Language：English Publishing type：Research paper (scientific journal)
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Existence of stable Fe(II) complex in oxic river water and its determination Reviewed
Y. Suzuki, K. Kuma, I. Kudo, K. Hasebe, K. Matsunaga
Water Research 26 ( 11 ) 1421 - 1424 1992.11
Language：English Publishing type：Research paper (scientific journal)
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Dissolution rate and solubility of colloidal hydrous ferric oxide in seawater Reviewed
共著者：K. Kuma, S. Nakabayashi, Y. Suzuki, K. Matsunaga
Marine Chemistry 38 ( 1-2 ) 133 - 143 1992.6
Language：English Publishing type：Research paper (scientific journal)
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Stabilization and determination of Fe(II) in seawater and its concentration in Harimanada Reviewed
Y. Suzuki, S. Nakabayashi, K. Kuma, I. Kudo, K. Matsunaga
Bulletin of Japanese Society of Fisheries and Oceanography 56 ( 3 ) 271 - 275 1992.3
Language：English Publishing type：Research paper (scientific journal)
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Photo-reduction of Fe(III) by dissolved organic substances and existence of Fe(II) in seawater during spring blooms Reviewed
K. Kuma, S. Nakabayashi, Y. Suzuki, I. Kudo, K. Matsunaga
Marine Chemistry 37 ( 1-2 ) 15 - 27 1992.3
Language：English Publishing type：Research paper (scientific journal)
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Uptake rate of iron by macroalgae from Sea of Japan(Laminaria religiosa Miyabe and Undaria pinnatifida) Reviewed
K. Matsunaga, Y. Suzuki, K. Kuma, I. Kudo, S. Nakabayashi
Bulletin of Japanese Society of Fisheries and Oceanography 55 ( 4 ) 349 - 353 1991.4
Language：English Publishing type：Research paper (scientific journal)