摘要：Poly-β-hydroxybutyric acid (PHB) was considered as one of the floc-forming substances in activated sludge. PHB content in activated sludge was examined and the following results were obtained. 1. PHB was isolated from activated sludge acclimatized with synthetic sewage. The melting point and infrared spectrum of this substance agreed with those of bacterial PHB. Elemental analytical values also agreed with theoretical values. 2. Turbidiy was recognized as a useful method for quantitative determination of PHB in activated sludge. 3. When glucose was added to activated sludge, PHB content in activated sludge increased, but decreased after several hours. 4. When various substances were added to activated sludge, PHB content increased. Compared with PHB content after addition of glucose, PHB content was larger after addition of acetate or alanine, almost the same after addition of galactose, peptone, casein, or glutamate, and smaller after addition of urea, saccharose, or starch. 5. Nitrogen sources were added to activated sludge simultaneously with glucose and PHB production was compared with that after addition of glucose alone. The effect of nitrogen sources was not apparent. 6. Almost the same amount of PHB as in acclimatized activated sludge was determined in the sludge from aerobic treatment plant of non-diluted night soil and non-diluted swine excrement.
