Role of quorum sensing-based regulation in development of anaerobic ammonium oxidation process

Shortage of anaerobic ammonium oxidation (anammox) sludge greatly limits the extensive full-scale application of anammox-based processes. Although numerous start-up strategies have been proposed, the interaction among microbial consortia and corresponding mechanism during the process development remain unknown. In this study, three reactors were established based on different seed sludges. After 27 days, the anammox process inoculated with anammox granules and activated sludge (1:5) was firstly achieved, and the highest nitrogen removal rate was 1.17 kg N m- 3 d-1. Correspondingly, the anammox activity and abundances of related func-tional genes increased. Notably, the dominant anammox bacteria shifted from Candidatus Kuenenia to Candidatus Brocadia. Metagenomic analysis indicated that quorum sensing-based regulation mainly contributed to the proliferation and accumulation of anammox bacteria. This work provides an insight into the quorum sensing (QS)-regulated microbial interactions in the anammox and activated sludge consortia during the process development.

Automated summary

Shortage of anammox sludge limits the application of anammox-based processes. In this study, three reactors were established using different seed sludges. After 27 days, anammox process with the highest nitrogen removal rate of 1.17 kg N m-3 d-1 was achieved using anammox granules and activated sludge. The dominant anammox bacteria shifted from Candidatus Kuenenia to Candidatus Brocadia, and quorum sensing-based regulation contributed to the growth of anammox bacteria.