Ryuhei Nakamura

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Extracellular redox-active compounds, flavins and other quinones, have been hypothesized to play a major role in the delivery of electrons from cellular metabolic systems to extracellular insoluble substrates by a diffusion-based shuttling two-electron-transfer mechanism. Here we show that flavin molecules secreted by Shewanella oneidensis MR-1 enhance the(More)
Pure-culture studies have shown that dissimilatory metal-reducing bacteria are able to utilize iron-oxide nanoparticles as electron conduits for reducing distant terminal acceptors; however, the ecological relevance of such energy metabolism is poorly understood. Here, soil microbial communities were grown in electrochemical cells with acetate as the(More)
Shewanella is an electrogenic microbe that has significant content of c type cytochromes (ca. 0.5 mM). This feature allows the optical absorption spectra of the cell-membrane-associated proteins to be monitored in vivo in the course of extracellular respiratory electron-transfer reactions. The results show significant differences to those obtained in vitro(More)
Although members of the genus Shewanella have common features (e.g., the presence of decaheme c-type cytochromes [c-cyts]), they are widely variable in genetic and physiological features. The present study compared the current-generating ability of S. loihica PV-4 in microbial fuel cells (MFCs) with that of well-characterized S. oneidensis MR-1 and examined(More)
Prometaphase cells were used to analyze the karyotype of Nicotiana kawakamii Y. Ohashi by means of sequential Giemsa/CMA/DAPI staining and multicolor fluorescence in situ hybridization with 5S and 18S rDNA. Observation of the DAPI-stained prometaphase spreads indicated that N. kawakamii had six pairs of large chromosomes, one pair of medium-sized(More)
The development of Mn-oxide electrocatalysts for the oxidation of H(2)O to O(2) has been the subject of intensive researches not only for their importance as components of artificial photosynthetic systems, but also as O(2)-evolving centers in photosystem II. However, limited knowledge of the mechanisms underlying this oxidation reaction hampers the ability(More)
Primary intermediates of oxygen photoevolution (water photooxidation) reaction at the TiO2 (rutile)/aqueous solution interface were investigated by in situ multiple internal reflection infrared (MIRIR) absorption and photoluminescence (PL) measurements. UV irradiation of TiO2 in the presence of 10 mM Fe3+ in the solution caused the appearance of a new peak(More)