The effect of a dietary soy protein isolate (SPI), soy peptide (PEP) and the amino acids in soy protein on paraquat (PQ)-induced oxidative stress was investigated in rats. In the first experiment, male Wistar rats were fed on experimental diets containing casein (CAS), SPI and PEP as nitrogen sources with or without 0.025% PQ. The reduced food intake and body weight gain of the rats fed with PQ was mitigated by either the SPI or PEP intake. Both SPI and PEP prevented the elevation of the serum TBARS concentration and tended to prevent the elevation of lung weight induced by PQ. In the second experiment, the rats were fed on diets containing an amino acid mixture resembling casein (CASAA) or soy protein (SPIAA) with or without PQ. The SPIAA intake did not affect the reduction of food intake and body weight gain, nor the elevation of lung weight and TBARS in the serum and liver induced by PQ. These results demonstrate that the intake of either dietary SPI or PEP, but not an amino acid mixture resembling soy protein, had the effect of reducing PQ-induced oxidative stress in rats.

: We developed an effective system to eliminate microorganisms from environmental water using cationic polyester fibers. The polyester fibers were cationized by dipping with 1% Poly (diallyldimethyammonium chloride) solution. The zeta potential of polyester fiber particles and some bacteria was measured using microscopic electrophoresis. The mean zeta potential of regular polyester fiber particles was -25mV and cationic polyester fiber particles was +45mV. The mean zeta potential of the bacteria, Bacillus subtilis was -15mV, Escheria coli, -25mV Legionella pneumophila, -25mV. The microbial suspension is pumped through the cationic polyester fiber filter. Bacteria electro-adsorption to the cationic polyester fibers was examined by bioassay. Relatively large numbers of bacteria could be removed by adsorption to the cationic polyester fiber. It was observed by electron microscopy that the bacteria adsorbed on the surface of cationic polyester fibers.