In this study, soil macrofauna in the beds of a full-scale vertical flow constructed wetland were investigated to clarify the effects of vegetation on diversity of soil macrofauna. The investigation was conducted in the vegetative growth stage when plant had a great growth vigor. Because deposits were retained on the surface, macrofauna were investigated only the beds of the first stage. The macrofaunal abundance in vegetated beds was higher than in unvegetated beds, suggesting that vegetation increased macrofaunal diversity. This finding shows that the diversity of vegetation-dependent species generates a different level of diversity in the vegetative growth stage. Though the constructed wetland received rich deposits, i.e. food resources, vegetation affected macrofaunal diversity. Earthworms were most abundant in the 0－10 cm layer of vegetated beds, while their abundance peaked in the 10－20 cm layer of unvegetated beds. These findings may show that importantly, vegetation softens rapid changes in the environment (ex. soil temperature), rather than providing food resources for macrofaunal diversity. It was revealed that plant played an important role on macrofaunal diversity even in the constructed wetland where organic matters were constantly provided from wastewater.

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The spread of antibiotics and antibiotic-resistant bacteria in aquatic environments has become a major problem all over the world, and preventing the proliferation of resistant bacteria is one of the foremost concerns for global health. To achieve effective prevention, it is important to analyze antibiotic resistance genes and their expression mechanisms. Pseudomonas aeruginosa is a ubiquitous environmental gram-negative bacterium that adapts rapidly to antibiotic-contaminated environments, and harbors many unknown resistance-related genes in its genome. To identify new antibiotic resistance-related genes, randomly-sheared 8380 strain chromosomal DNA fragments were introduced into 8380 cells by using pUCP24. DNA fragments containing the scfB gene conferred resistance to various antibiotics and the resistant profile was similar to that of NfxC-type mutants expressing the MexEF-OprN efflux pump in an MexT-dependent manner. Wild-type 8380 cells did not express MexEF-OprN due to inhibition of MexT by active MexS. Since 8380 cells with introduction of the scfB gene expressed the MexEF-OprN efflux pump, but 8380?mexT cells with introduction of this gene did not, it was demonstrated that scfB induced the MexEF-OprN efflux pump in an MexT-dependent manner. Moreover, overexpression of scfF, a homologue of scfB, induced MexEF-OprN expression. These results suggest that the genome of P. aeruginosa contains many unknown resistance-related genes.

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This study aimed to elucidate the effects of coagulation on filtration treatment for picophytoplankton removal. We analyzed the treatment and coagulation characteristics observed during filtration treatments by using a coagulation-sedimentation filtration experiment with cultured picophytoplankton. We found that the particle size distribution of leakage from the coagulation-sedimentation filtration was observed with a peak of 4.2 μm, revealing that the leakage had formed a fine floc rather than non-coagulation. In the coagulation treatment of picophytoplankton, when a low coagulant dose was injected, particle size of the floc was formed ＜ 10 μm, and if a high coagulant dose was injected, particle size of the floc was formed ＜ 10 μm through re-dispersion of the floc. The results clearly show that injecting the optimal coagulant dose to maintain the size of the floc infiltrating the filter layer at ＞ 10 μm would play a vital role in preventing filtration leakage.

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The optimal temperature for anaerobic ammonium oxidation (anammox) is generally 30－37℃. This temperature range, which is higher than usual wastewater temperature, implies that the anammox reactor requires heat energy for efficient nitrogen removal. Therefore, the anammox process which is applicable at ambient temperature (20－25℃) is needed to develop more versatile and sustainable nitrogen removal technologies. This study was conducted to start-up lab-scale anammox reactors packed with a nonwoven fabric material at 20℃ using various inoculum sources. Reactor 1 was inoculated with activated sludge sampled in Kumamoto, a temperate region of Japan. Reactor 2 was inoculated with activated sludge obtained from Hokkaido, a subarctic region. Reactor 3 was inoculated with groundwater microorganisms sampled from Kumamoto. At 800 days from the start-up of the reactors, Reactors 1 and 2 achieved high nitrogen removal rates (NRR) of 0.64 kg－N/m³/day at 20℃ with the typical anammox reaction ratio. Although the nitrogen removal was unstable, the NRR increased to 0.38 kg－N/m³/day in Reactor 3 after 700 days. The nitrogen reaction ratio in Reactor 3 indicated the simultaneous occurrence of anammox and nitrification. Results suggest that anammox bacteria, which can grow at ambient temperature, are ubiquitous in the environment.

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Through mid-May from 2009 late April, Synedra acus of diatoms is overgrowth in the dam of Chikugo River upstream. Filter clogging has occurred in Araki water purification plant. In Araki water purification plant, the head loss of filter rose sharply. On the other hand, We have to strengthen the coagulation treatment by the increase in the amount of water treatment chemicals and reduced the filter run time. However, since Synedra acus in the raw water grew day by day, we could not achieve a sufficient effect. As a result, the function of water treatment was significantly reduced.For these situations, we have emergency introduced change prechlorine injection point and the multi layer filtration. In the former, we could be improved by about 20％ a coagulating sedimentation removal effect in sedimentation pond. In the latter, we were able to suppress an increase in head loss by laying 50mm thickness anthracite about to half of the filter. These results, the function of water treatment has been restored.

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