Phosphate-removing ability of purple non-sulfur bacteria anaerobicly cultivated with different energy source

• Main Authors: Shu-Chuan Hsu, 許淑娟
• Other Authors: 洪俊雄
• Format: Others
• Language: zh-TW
• Published: 2006
• Online Access: http://ndltd.ncl.edu.tw/handle/80359496022481923821

碩士 === 國立中興大學 === 環境工程學系所 === 94 === Biological phosphorus removal from wastewater had been accomplishing in activated sludge reactors by proper process design. One of the potential PAOs in EBPR system was believed to be the Rhodocyclus-related microorganism which was identified phylogenetically close to the Rhodosiprillums. However, the role they play in systems have not been fully understood yet. Previous studies from our research demonstrated that the purple nonsulfur bacteria isolated from activated sludge could remove phosphorus from wastewater by accumulate it as intracellular polyphosphate. Polyphosphate-accumulating ability of the phototrophic purple nonsulfur bacteria was found to be twice stronger than other PAOs in both anaerobic and aerobic condition, and this model of biological phosphorus removal were different with the PAOs model described by scientists. Furthermore, the results also showed that most of the isolated pure cultures could accumulate polyphosphate under both anaerobic-only and aerobic-only condition. This observation was not only never been reported on the literatures but also quite different from the well-known anaerobic/aerobic cycling phosphorus accumulation model. It was demonstrated that bioaugmentation of purple nonsulfur bacteria with high polyphosphate accumulating ability into lab-scale activated sludge system could enhance the overall efficiency of phosphorus removal. All of these results prompted an interesting research subject on the phosphorus accumulating mechanism the purple nonsulfur bacteria. In this proposal, polyphosphate accumulating phenomenon performed by the purple nonsulfur bacteria and the pathway of this polyphosphate metabolism were studied. Results of this study showed that Rhodopseudomonas palustris GN11 could accumulate polyphosphate when anaerobicly incubated, and it started accumulating polyphosphate when entering the stationary phase. Results of this study will be helpful to understand and promote to establish a polyphosphate accumulating mechanism by purple nonsulfur bacteria.