2009 Volume 7 Issue 4 Pages 215-223
The acetate uptake by polyphosphate accumulating organisms (PAOs) and glycogen accumulating organisms (GAOs) were compared under different pH conditions. These two microorganisms are known to play key roles in the enhanced biological phosphorus removal (EBPR) processes. In this study, micro-autoradiography (MAR) with acetate as the radio-labeled substrate and fluorescence in situ hybridization (FISH) with PAOmix probe and GB probe were applied. Activated sludge samples taken at a wastewater treatment plant were subjected to anaerobic batch incubation with radio-labeled acetate at different initial pH conditions. The relative amount of carbon uptake by each cell was estimated based on the silver granule area around the cell. The results showed that anaerobic acetate uptake by PAOmix-positive and GB-positive cells were affected by the initial pH. Both PAOs and GAOs were found to have a weak tendency to take up less acetate under higher initial pH conditions.
