Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Shiraishi, Fumito*; Chihara, Ryoji*; Tanimoto, Risa*; Tanaka, Kazuya; Takahashi, Yoshio*
Island Arc, 31(1), p.e12448_1 - e12448_9, 2022/05
Times Cited Count：0 Percentile：0(Geosciences, Multidisciplinary)At Yunotaki Fall in north Japan, manganese-oxidizing bacteria were previously assumed to have oxidized manganese to precipitate birnessite, which relied on oxygen released from algae. However, it remained unclear whether larger-scale manganese oxide precipitation was actually occurring under light conditions. This study evaluated the contribution of indirect oxidation using microelectrodes to analyze local water chemistry, in addition to bulk water chemistry and DNA analyses. The results of this study demonstrate that low bulk pH values in the hot spring water hindered indirect oxidation despite the occurrence of active oxygenic photosynthesis and that direct oxidation by manganese-oxidizing bacteria is considered to dominate in the investigated sample.
and Mn by fungal manganese oxide through asbolane formationAoshima, Miku*; Tani, Yukinori*; Fujita, Rina*; Tanaka, Kazuya; Miyata, Naoyuki*; Umezawa, Kazuhiro*
Minerals (Internet), 12(3), p.358_1 - 358_16, 2022/03
Times Cited Count：5 Percentile：77.65(Geochemistry & Geophysics)In this study, we conducted sequestration experiments of Co by 
KR21-2 in a Mn/Co binary solution at pH7. The sequestration of Co by newly formed BMOs readily progressed in parallel with the exogenous Mn, with higher efficiency than that in single Co solutions. This is attributed to a synergetic effect on Co sequestration through the formation of asbolane in Mn/Co binary systems.
Tanaka, Kazuya; Tani, Yukinori*; Kozai, Naofumi; Onuki, Toshihiko
Journal of Radioanalytical and Nuclear Chemistry, 331(2), p.1109 - 1114, 2022/02
Times Cited Count：0 Percentile：0.01(Chemistry, Analytical)We investigated the sorption of Pu(IV) on biogenic Mn oxide produced by Mn(II)-oxidizing fungus. The sorption of Pu(IV) on biogenic Mn oxide was similar to that of U(VI) and different from that of Th(IV), possibly due to oxidation of Pu(IV) to Pu(VI). When Pu(IV) was sorbed on hyphae only, it was desorbed into the solution phase over time. Pu(IV) could be solubilized by complexation with organic ligands secreted by fungal cells. In particular, Pu(IV) desorption was observed under circumneutral pH conditions.
Suzuki, Ryohei*; Tani, Yukinori*; Naito, Hirotaka*; Miyata, Naoyuki*; Tanaka, Kazuya
Catalysts, 10(1), p.44_1 - 44_15, 2020/01
Times Cited Count：10 Percentile：40.35(Chemistry, Physical)We prepared biogenic Mn oxides (BMOs) using strain KR21-2, and subsequently conducted single or repeated treatment experiments in Cr(NO
) at pH6.0. Under aerobic conditions, newly formed BMOs exhibited a rapid production of Cr(VI) without a significant release of Mn(II), demonstrating that newly formed BMO mediates a catalytic oxidation of Cr(III) with a self-regeneration step of reduced Mn. In anaerobic solution, newly formed BMOs showed a cessation of Cr(III) oxidation in the early stage of the reaction, and subsequently had a much smaller Cr(VI) production with significant release of reduced Mn(II).
Fukuyama, Kenjin; Ohara, Yoshiyuki
no journal, ,
no abstracts in English
Takeda, Ayaka*; Nakano, Yuriko*; Ochiai, Asumi*; Yokoo, Hiroki*; Ohara, Yoshiyuki; Fukuyama, Kenjin; Nagayasu, Takaaki; Onuki, Toshihiko*; Utsunomiya, Satoshi*
no journal, ,
no abstracts in English
Yamaji, Keiko*; Ohara, Yoshiyuki; Fukuyama, Kenjin; Nagayasu, Takaaki; Haruma, Toshikatsu; Tanaka, Kazuya; Masuya, Hayato*; Habe, Hiroshi*
no journal, ,
no abstracts in English
