A novel molecular photocatalytic system with not only high reduction ability of CO but also high capture ability of CO has been developed using a Ru(II)-Re(I) dinuclear complex as a photocatalyst. By using this photocatalytic system, CO of 10% concentration could be selectively converted to CO with almost same photocatalysis to that under a pure CO atmosphere (TON > 1000, ΦCO > 0.4). Even 0.5% concentration of CO was reduced with 60% initial efficiency of CO formation by using the same system compared to that using pure CO (TON > 200). The Re(I) catalyst unit in the photocatalyst can efficiently capture CO, which proceeds CO insertion to the Re-O bond, and then reduce the captured CO by using an electron supplied from the photochemically reduced Ru photosensitizer unit.

This is the first report to explore the fine-scale diversity, population genetic structure, and biogeography of a typical planktonic microbe in Japanese and Korean coastal waters and also to try to detect the impact of natural and human-assisted dispersals on the genetic structure and gene flow in a toxic dinoflagellate species. Here we present the genetic analysis of Alexandrium tamarense (Lebour) Balech populations from 10 sites along the Japanese and Korean coasts. We used nine microsatellite loci, which varied widely in number of alleles and gene diversity across populations. The analysis revealed that Nei's genetic distance correlated significantly with geographic distance in pair-wise comparisons, and that there was genetic differentiation in about half of 45 pair-wise populations. These results clearly indicate genetic isolation among populations according to geographic distance and restricted gene flow via natural dispersal through tidal currents among the populations. On the other hand, high P-values in Fisher's combined test were detected in five pair-wise populations, suggesting similar genetic structure and a close genetic relationship between the populations. These findings suggest that the genetic structure of Japanese A. tamarense populations has been disturbed, possibly by human-assisted dispersal, which has resulted in gene flow between geographically separated populations. 1

We established clonal cultures of Dinophysis acuminata Clap. et Lachm. and D. fortii Pavill. isolated from western Japan and examined toxin production in them, focusing on intracellular production and extracellular excretion. At the end of incubations, the total amounts of pectenotoxin-2 (PTX-2), dinophysistoxin-1 (DTX-1), and okadaic acid (OA) in the D. acuminata cultures reached up to 672.7 ± 14.7 (mean ± SD), 88.1 ± 2.8, and 539.3 ± 39.7 ng · mL(-1) , respectively, and the excreted extracellular amounts were equivalent to 5.1, 79.5, and 79.5% of the total amounts, respectively. Similarly, at the end of incubations, the total amounts of PTX-2, DTX-1, and OA in the D. fortii cultures reached up to 526.6 ± 52.6 (mean ±SD), 4.4 ± 0.4, and 135.9 ± 3.9 ng · mL(-1) , respectively, and the excreted extracellular amounts were equivalent to 1.8, 80.1, and 86.6% of the total amounts, respectively. Further, we tested the availability of cell debris and dissolved organic substances that originated from the ciliate prey Myrionecta rubra for growth and toxin production in D. acuminata. Although no significant growth was observed in D. acuminata in the medium containing the cell debris and organic substances originated from M. rubra, the toxicity was significantly greater than that in the control (P < 0.05-0.001); this finding suggested the availability of organic substances for toxin production. However, toxin productivity was remarkably lower than that of Dinophysis species feeding on living M. rubra.

Electrocatalytic reduction of low concentration CO2 was selectively and efficiently carried out by using a Re(I) complex with high CO2-capturing ability.

We analyzed cryptophyte nucleomorph 18S rRNA gene sequences retained in natural Myrionecta rubra cells and plastid 16S rRNA gene and psbA sequences retained in natural cells of several Dinophysis species collected from Japanese coastal waters. A total of 715 nucleomorph sequences obtained from 134 M. rubra cells and 564 plastid 16S rRNA gene and 355 psbA sequences from 71 Dinophysis cells were determined. Almost all sequences in M. rubra and Dinophysis spp. were identical to those of Teleaulax amphioxeia, suggesting that M. rubra in Japanese coastal waters preferentially ingest T. amphioxeia. The remaining sequences were closely related to those of Geminigera cryophila and Teleaulax acuta. Interestingly, 37 plastid 16S rRNA gene sequences, which were different from T. amphioxeia and amplified from Dinophysis acuminata and Dinophysis norvegica cells, were identical to the sequence of a D. acuminata cell found in the Greenland Sea, suggesting that a widely distributed and unknown cryptophyte species is also preyed upon by M. rubra and subsequently sequestered by Dinophysis. To confirm the reliability of molecular identification of the cryptophyte Teleaulax species detected from M. rubra and Dinophysis cells, the nucleomorph and plastid genes of Teleaulax species isolated from seawaters were also analyzed. Of 19 isolates, 16 and 3 clonal strains were identified as T. amphioxeia and T. acuta, respectively, and no sequence variation was confirmed within species. T. amphioxeia is probably the primary source of prey for M. rubra in Japanese coastal waters. An unknown cryptophyte may serve as an additional source, depending on localities and seasons.The marine dinoflagellate genus Dinophysis comprises photosynthetic and nonphotosynthetic members and is globally distributed in coastal and oceanic waters (12,29,30). Several members of the genus Dinophysis produce potent polyether toxins that can accumulate in filter-feeding bivalves, leading to a syndrome known as diarrhetic shellfish poisoning (DSP) in humans who consume tainted shellfish. These toxic algal species are important not only for their potential impact on public health but also from an ecological point of view because of their dual role as primary and secondary producers in complex microbial food webs. Despite extensive studies over the last 2 decades, little is known about the ecophysiology, toxicology, and bloom mechanisms of DSP-causing species of Dinophysis, primarily due to an inability to culture them. Since the first successful cultivation of Dinophysis acuminata by Park et al. (42), the understanding of Dinophysis biology and ecology has progressed considerably. Three other species (Dinophysis caudata, Dinophysis fortii, and Dinophysis infundibulus) are now available in culture, and it has become clear that these different Dinophysis species require the presence of both cryptophytes and the marine ciliate Myrionecta rubra to grow and proliferate (36,37,38). When presented with the marine ciliate M. rubra as prey, the four Dinophysis species mentioned...