We focused on the phototaxis of cypris larvae to prevent their settlement on a ship's hull. Preventing settlement on the top surface （3 mm thickness） was particularly important so as not to increase the shade from the juveniles settled there. The maximum irradiance at the top surface was 550.0－ 560.0 （W m^-2）. A cylinder （diameter 15.4 cm; axial length 40 cm） was used to compare the efficiency of phototaxis attracted by the different colors of light from a source placed inside the closed end. A total of 1,101 individuals settled on the surface when red light was being emitted, while only 2 individuals were on it when there was no light. All individuals settled above the tip of a blue LED stopped metamorphosing, indicating that a higher irradiance blue light inhibits some metamorphosis processes. That indirectly contributes to a reduction of biofouling on the plate surface. The effectiveness of blue light sources composed of three, nine, and thirty-six LEDs on the reduction of the settlement frequency was quantified when the emission was performed from a distance of 40 cm from the center on the flat surface （40 cm square）. The value of the relative population density in the central area was drastically reduced from 0.2 to 0.06 （％ cm^-2） in response to an increase in the number of LEDs from three to nine. The value decreased slightly to 0.04 （％ cm^-2） with thirty-six LEDs. We also examined the effectiveness of the arrangement of four light sources, each of which was composed of nine LEDs and was emitting equally toward a quarter the area of a surface. In that case, an 80.8 ％ reduction of the settlement frequency was obtained as compared to that of the control, while the value was 61.6 ％ when a single light source of thirty-six LEDs was emitting toward the central area on the plate surface, indicating that an emission that covers a wider area reduces the settlement frequency by attracting cypris larvae effectively toward the light source. The blue LED light with higher irradiance was found to have application for maintaining a smooth hull surface.

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Pro-form of halophilic thermolysin-like proteinase, salilysin, was processed three times to form intermediate 1 (I1), intermediate 2 (I2) and final mature form (M). Halophilic enzymes are generally characterized by enhanced stability and catalytic activity in the presence of high concentration of salts. Autolytic processing of I1-form salilysin to I2-form and M-form in vitro was enhanced with the addition of 1.0 M and 0.5 M salts in parallel to valency and general salting-out effects of salts: NaCl ⁄ KCl < NH₄Cl < (NH₄)₂SO₄ ⁄ Na₂SO₄ ⁄ MgSO₄. Mg salts at lower concentration, 0.1 M, regardless of salting-out (MgSO₄: exerting stabilizing effects on protein structures) or salting-in (MgCl₂: exerting destabilizing effects) salts, showed the highest efficiency in enhancing autolysis of I1 to mature form, suggesting importance of Mg ion in addition to the general salting-out effects of high concentration of salts. Even 5 ～ 10 mM Mg salts clearly enhanced autolysis of I1 and processing of inactive pro-E167A salilysin by wild-type mature salilysin, thus again suggesting distinct effects of Mg ion. Processing and maturation of halophilic salilysin was both enhanced by general salting-out effects of various salts and by specific effects, most likely possible binding to salilysin, of Mg ion.

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Bioethanol is one of the most widely used biofuels as automotive fuel on a global scale. Here, we describe research progress in bioethanol production using seawater. To select bacterium that can grow efficiently in a medium using seawater, sulfate tolerance capacity was estimated for ethanol-producing strains such as Issatchenkia orientalis NBRC1279^T, Candida krusei NBRC1664 and Saccharomyces cerevisiae BY4742. Among these strains, C. krusei NBRC1664 showed the fastest growth. When C. krusei NBRC1664 was cultured using 40 ％ seawater as the medium component, 8.34 g/L ethanol was produced from 20 g/L glucose after 48 h of incubation, consistent with the concentration by cultivation in YNBG medium. This result suggests that seawater is a potentially useful medium component for ethanol production as the use of seawater reduces production costs by reducing the amount of freshwater used in the production.

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Circulating diffusion dialysis （CDD） is a power-free desalination technique that uses salinity gradient energy. To improve the desalination performance of CDD, desalination tests were conducted using two types of ion exchange membranes with different transport properties. At low concentration （1000 ppm NaCl solution）, membranes with lower area resistance exhibited higher desalination performance, whereas at higher concentration （5000 ppm NaCl solution）, membranes with lower permeability to water and salt were more effective.

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In electrodialysis （ED） using ion-exchange membranes （IEMs）, the occurrence of scale precipitation makes continuous operation of the equipment difficult. As a solution to this problem, we developed a monovalent selective cation-exchange membrane （MS-CEM） prepared via plasma-induced graft polymerization by grafting monomers with oppositely charged groups onto a commercial （ungrafted） CEM. As a result, the permselectivity of the prepared MS-CEM was approximately 4.3 times higher than that of the ungrafted CEM.

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A sensitive and simple analytical system for the determination of 1-deoxynojirimycin (DNJ) was established using hydrophilic interaction liquid chromatography (HILIC) with tris（2,2'-bipyridine）ruthenium (II) - electrogenerated chemiluminescence detection. Chromatographic separation of DNJ was achieved on a TSKgel Amide-80 column (5 μm, 250 x 4.6 mm id). The mobile phase was an 82:18 (v/v) mixture of acetonitrile and 5 mM KH₂PO₄ buffer (pH 5.8), flowing at 0.9 mL/min. In addition, 10 mM KH₂PO₄ buffer (pH 7.5) was mixed at 0.3 mL/min post column to raise the pH of the mobile phase to the optimal pH for detection. A 1.5 mM H₂SO₄ solution containing 0.3 mM tris（2,2'-bipyridine）ruthenium (II) chloride was used as the detection reagent solution, which was circulated at 0.4 mL/min through electrochemiluminescence detector (COMET 3000) controlled to 80 μA oxidation current. These optimized conditions were used for quantitative analysis of DNJ. The detection and quantification limits of DNJ were 0.1 and 0.15 μg/mL, respectively, and the calibration curve showed good linearity (r ² > 0.9999) in the range of 0.15-20 μg/mL. The recovery rate of DNJ from the mulberry leaves samples was more than 97 ％. Moreover, the DNJ content of five mulberry leaf tea products was determined using this analytical system and was found to vary between 0.03 ％ and 0.21 ％ depending on the product. These results demonstrate the applicability of this analytical system for quantitative analysis of DNJ in mulberry leaves, and its promising potential for application in marine bioprospecting.

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The removal of radioactive Cs from aquatic environments following nuclear disasters is critical for environmental remediation. Prussian blue （PB） and cobalt ferrocyanide （FC） are well-known Cs adsorbents; however, their fine particle sizes hinders their separation from water after adsorption. To overcome this problem, PB and FC were immobilized on various adsorbents, including alginate beads, cellulose beads, viscose rayon, and bubble wrap. The PB-loaded bubble wrap exhibited the highest Cs adsorption efficiency. Furthermore, potassium-modified PB （KPB） exhibited a higher adsorption capacity than unmodified PB, demonstrating the effectiveness of potassium as an additive. The adsorption behavior was well described by the Langmuir adsorption isotherm model. Kinetic analysis revealed that Cs adsorption onto the KPB-loaded bubble wrap followed a pseudo-second-order rate equation law, indicating chemisorption was the main mechanism. These results show the KPB-loaded bubble wrap is a stable and effective adsorbent for Cs removal.

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