Development of algae-bacteria granular consortia in photo-sequencing batch reactor

- Aerobic granules can be used as the immobilized material of eukaryotic algae.
- EPS bridge function is dominant developed mechanism of the granular consortia.
- Cyanobacteria will not displace the dominance of eukaryotic algae in consortia.
- Competition for aerobic zone occur among aerobe, photoheterotrophs and algae.

The development and properties of algae-bacteria granular consortia, which cultivated with the algae (Chlorella and Scenedesmus) and aerobic granules, was investigated in this experiment. The results indicated that the granular consortia could be successfully developed by selection pressure control, and the algal biomass and extracellular polymeric substances (EPS) concentration in the consortia showed notable correlation with the operating parameters of reactor. The maximum specific removal rates of total nitrogen and phosphate were obtained from the granular consortia with the highest algal biomass, yet the correlation between the fatty acid methyl esters yield and the algal biomass in the consortia was not markedly observed. The seed algae maintained dominance in the phototroph community, whereas the cyanobacteria only occupied a small proportion (5.2-6.5%). Although the bacterial communities with different operational strategies showed significant difference, the dominated bacteria (Comamonadaceae, 18.79-36.25%) in the mature granular consortia were similar.

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