抄録
Due to a great progress in molecular techniques in microbial community analysis, microbes in enhanced biological phosphorus removal (EBPR) activated sludge are now intensively investigated. Several new candidates for polyphosphate accumulating organisms (PAOs) are now discovered or proposed. In this research, laboratory scale reactors were operated using glucose or aspartate as a sole carbon source and the microbial community was investigated using PCR-DGGE, cloning and FISH. In the aspartate fed reactor, Dechloromonas related bacteria which accumulated polyhydroxyalkanoate (PHA) but not polyphosphate (behaving like glycogen accumulating organisms (GAOs)) was found to exist significantly even when phosphate was well removed. On the other hand, in the glucose fed reactor, three Actinobacteria related genotypes were found. Although these genotypes were closely related to each other, one existed significantly when phosphate was removed well, and the others were found when the phosphorus removal activity was deteriorated. In both reactors, Rhodocyclus related PAO candidate was found at a certain level (about 20% of eubacteria) when the phosphorus was removed well, but the DGGE band corresponding to the bacteria didn't correspond to the profile of phosphorus removal activity.In this way, the complexity of microbial communities in EBPR activated sludge was shown.
