Polyhydroxyalkanoates (PHAs) are accumulated in many gram-positive and gram-negative bacteria as intracellular carbon and energy storage material under nutrient-limited conditions. Bacterial PHAs are expected to become attractive alternatives for petrochemically based plastics, since they are biodegradable thermoplastics. Typical bacterial PHA, poly-3-hydroxybutyrate [P (3HB) or PHB], is highly crystalline, stiff and brittle. The lack of flexibility limits the range of its applications. The copolyester of (R) -3HB and longer chain (R) -3-hydroxyalkanoate, P (3HB-co-3HA), is less crystalline, more ductile, easier to mold and tougher than P (3HB). Based on the PHA biosynthesis mechanism, control of monomer composition in PHA by genetic and metabolic engineering makes it possible to synthesize a copolyester with good properties.
A low molecular weight PHB, termed OHB, has been identified as complexes with other biomacromolecules in a wide variety of organisms from bacteria, to plants and animals. The supermolecular complex of OHB with calcium ion-polyphosphate was demonstrated to be a prebiotic calcium ion transport channel and to be closely related to genetic competency for transforming Escherichia coli. Further studies on the physiological functions of OHB including calcium ion channel formation would pioneer the stage for future PHB polymer science.

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The surface potentials (Δψ) of the mixed micelles composed of arachidonic acid (AA) and nonionic heptaethylene glycol dodecyl ether (HED) were estimated at 25 and 60°C by measuring the fluorescence intensity of 8-anilino-1-naphthalenesulfonate (ANS) as a fluorescent probe. The surface potentials of AA-HED mixed micelles, |-Δψ|, increased with increasing mole fraction of AA (X_AA), and decreased with increasing ionic strength (I). These changes are due to the effects of the negative charge of AA and of the ionic atmosphere of Na⁺, respectively. The surface charge density (σ) was nearly independent of I and proportional to X_AA, indicating that the surface state of AA-HED mixed micelles is represented by the Gouy-Chapman theory. The absolute value of σ for AA-HED mixed micelles at 60°C was slightly decreased as compared with that at 25°C.

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Micellar surface potentials (Δψ) of icosapolyenoic acids (IPA) having 25 double bonds were determined at 25°C from fluorescence intensity of ammonium 8-anilino-1-naphthalenesulfonate as a fluorescent probe. The surface potential, |-Δψ|, of IPA micelles decreased with increase in the number of double bond in the IPA molecule. Decrease in |-Δψ| by the introduction of a double bond in the IPA molecule was approximately 13.12mV at ionic strength 0.02mol dm^-3. The relationship was represented well by the following equation : Δψ/mV=-108.0+13.12n, where n is the number of C=C double bonds in an IPA molecule. Surface charge density |-σ| of IPA micelles based on the Gouy-Chapman theory was found to diminish as n increased. The relationship can be expressed well by the following equation : σ/c cm^-2=-3.386×10^-6+2.463×10^-6·(√n-√2), where n≥2.

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In order to provide more available substrates other than just vegetable oils for producing the glycolipid biosurfactant, mannosylerythritol lipid (MEL), by Candida antarctica T-34, MEL productivity was examined using various aliphatic hydrocarbon substrates under resting-cell conditions. The yield of MEL varied considerably depending on substrate used. MEL was produced in significant amounts from 1-alkenes (C₁₂ to C₁₈), 2-alkanols and 2-alkanones (C₁₂ to C₁₄). These alkanols and alkanones gave higher yields of MEL than the corresponding 1-alkanols with the same carbon chain-length. Among hydrocarbon substrates examined, 2-tetradecanol gave the highest yield of MEL (>30g/L), that was comparable yield produced with tetradecanoic acid. A comparison between the fatty acid profiles of MEL obtained from 2-alkanol and 2-alkanone substrates revealed only slight differences. In contrast, significant differences were observed between those from 2-alkanone and 3-alkanone substrates. These results suggest that the conversion of 2-alkanols into fatty acids to give the glycolipid is accomplished by the operation of a subterminal oxidation pathway, which consists of the steps catalyzed by a secondary alcohol dehyrogenase, Baeyer-Villiger monooxygenase and esterase. This is the first report on the involvement of a Baeyer-Villiger type of oxidation in biosurfactant production.

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Surface pressure-area curves for perfluoroalkanes (C₁₆F₃₄, C₂₀F₄₂ and C₂₄F₅₀) and novel perfluorodiacetylene (C₂₄F₄₂) showed monolayers to form on the surface of water. Monolayers of perfluorocompounds were deposited on various substrates by Langmuir-Blodgett (LB). A comparison of reflection-absorption and transmission IR spectra indicated difluoromethylene chains in LB film to be oriented perpendicularly to the substrate. Perfluoroalkane LB film (C₂₀F₄₂ and C₂₄F₅₀) on hydrophobized mica showed excellent water repellency with contact angles of water, 155° and 153°. Perfluorodiacetylene LB film on a KRS-5 plate demonstrated excellent water repellency with a contact angle of 162° and that on a quartz plate, after polymerization by UV irradiation, was highly electroconductive, with no need for doping or further treatment.

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The optimal conditions of chemiluminescence detection-high performance liquid chromatography (CL-HPLC) method for triacylglycerol hydroperoxide (TGOOH) determination were investigated. Gel permeation chromatography (GPC) column (TSKgel G1000H_XL) was most effective for the TGOOH determination, which can separate hampering α-tocopherol and give a single shape TGOOH peak without influence of fatty acid composition. For olive, safflower, perilla and fish oils, proportional correlationships were confirmed between the peroxide value (PV) and the CL peak area of TGOOH. The present method can determine TGOOH as low as PV 0.04meq/kg in 1mg sample oil and would be useful for studying mechanism of initial rancid reactions in edible oils.

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Bis-quaternary ammonium salts [C_m-Bis (N-C_n)] possessing two equivalent ammonium groups substituted with one long-alkyl chain (n : 1016) and two methyl groups, and a connecting alkanediyl chain (m : 26), were synthesized from alkyldimethylamine and 1, ω-dibromoalkane. Surface-active properties such as foaming and solubilization capacity were measured and the catalytic activity of bis-quaternary ammonium salts in phase transfer halide exchange reaction was examined.
Foam volume increased with increase in concentration of C_m-Bis (N-C_n) until it reached to nearly that of critical micelle concentration (cmc), in the region of which showed maximum foam volume. Foaming capacity and foam stability of C_m-Bis (N-C_n) increased with alkyl chain n (n : 10→12→14) and then decreased remarkably at n : 16. Both parameters decreased monotonously with increase in connecting chain m. The solubilizing power of C_m-Bis (N-C_n) increased with n and m (m : 2→6). Catalytic activity in a phase transfer reaction increased with n (n : 10→12→14), becoming maximum at 14, followed by decrease at 16. It increased with m (m : 2→3→4) but subsequently decreased with further increase in m.

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A kinetic equation for detergency of fatty acid soil as a function of solubilization capacity of washing liquid was studied. A cylindrical lump of palmitic acid was rotated in sodium dodecyl sulfate solution and the solute concentration was measured by a differential refractometer. The results could be applied to the first order kinetic equation in which the maximum solubilization amount is supposed to the initial concentration of reactant, and reactant concentration is supposed to solubilization capacity of the washing liquid. The detergency curves of soiled cloth failed to obey this equation. Geometric conditions of soil greatly affect the solubilization rate.

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For Plecoglossus altivelis and Limanda yokohamae grown in different ecological environments, ganglioside characteristics in the brain and liver were examined and compared by TLC.
As with sardine reported previously, polysialogangliosides having three or more sialic acid molecules bonded to each other were found present in the brain at high concentrations, while monosialoganglioside concentration in the liver was high.
These findings confirm organ-specificity. In Limanda yokohamae liver, GM2 was the main component present at 79.5%, GM4 and GD1a were detected, respectively, at 24.4% and 22.3% in Plecoglossus altivelis liver. These data differ from those for sardine whose GM4 content was 47.4%, suggesting remarkable differences among fish species. GM3 is the major component in higher vertebrate livers, and thus species-specificity may be considered reflected by ganglioside distribution in the liver.

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Trans Fatty acid intake in 1990 by Japanese was estimated as 1.8g/capita/day. Considering actual fat and oil intake to be less than supply and that trans fatty acid content had previously been determined by the IR method, the GLC method was used to estimate trans fatty acid content in hydrogenated oils produced in 1998 and also trans fatty acid intake from milk, dairy products, meat and edible vegetable oils.
1) The amount of trans fatty acid intake, based on consumption data of hydrogenated vegetable and animal oil, was 0.83g and 0.52g, respectively, a total was 1.35g. Based on differences in fat and oil intake (59.3g) and consumption (87.8g), actual intake of trans fatty acid was found to be 0.91g.
2) Approximately 0.65g trans fatty acid was from milk, dairy products, beef and refined edible oils. Total trans fatty acid intake of Japanese was thus determined as 1.56g/capita/day.

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