Start-up of anammox systems with different feeding patterns: System performance, microbial community and potential microbial interactions

•Pulse feeding anammox system had strong stability and perturbation resistance.•Candidatus Kuenenia and heterotrophs had complex microbial interactions.•Microbial interactions could affect nutrient metabolisms and information exchange.•C10-HSL and C12-HSL were the main detected signal substances for quorum sensing.