Three　simultaneous　partial　nitrification　and　denitrification　(SPND)　bioreactors　were　established　on　ambient　(30　degrees　C),　mesophilic　(40　degrees　C)　and　thermophilic　condition　(50　degrees　C)　at　high　dissolved　oxygen　levels　(2-7　mg　L-1)　to　remove　nitrogen　and　carbon　from　anaerobic　digestate　food　waste　effluent　(ADFE).　The　bioreactor　performed　best　under　mesophilic　condition,　with　TN　and　COD　removal　efficiency　of　96.3　+/-　0.1%　and　91.7　+/-　0.1%,　respectively.　Free　ammonia　(FA)　and　free　nitrous　acid　(FNA)　alternately　ensured　selective　inhibition　of　nitrite-oxidizing　bacteria　(NOB)　in　long-term　operation　of　SPND　systems.　Candidatus　Brocadia,　known　as　anammox　bacteria,　was　observed　unexpectedly　in　the　bioreactors.　The　analysis　of　microbial　community　and　metabolic　pathways　revealed　that　mesophilic　strategy　stimulated　SPND　and　anammox　process.　Mesophilic　condition　helped　autotropic　microbes　resist　the　competitive　pressure　from　heterotrophic　bacteria,　improving　the　balance　between　nitrifiers,　anammox　bacteria　and　other　co-existing　heterotrophs.　Overall,　this　study　offers　new　insights　into　the　linkage　among　temperature,　pollutant　removals　(carbon　and　nitrogen)　and　metabolic　potential　in　the　SPND　bioreactors.　(C)　2021　Elsevier　B.V.　All　rights　reserved.