Microbial dynamics during aerobic granulation under different phosphate concentration

The structure of the microbial community was followed during the formation of aerobic granule in a sequencing batch reactor. The influence of the phosphate concentration, from high to low, on the microbial community composition and the granule shape was studied. In the first part of the experiment, high concentration of phosphate, the biomass aggregated to form round shape granules along side with the enrichment of Candidatus Accumulibacter. In the second part of the experiment, when reducing the phosphate concentration, Propionivibrio became the most abundant microorganism and the granule remained round and bigger than 1000um.