The　feasibility　of　completely　autotrophic　nitrogen　removal　over　nitrite　(CANON)　process　for　treating　domestic　sewage　was　investigated　in　membrane　bioreactor　(MBR),　for　which　conventional　activated　sludge　was　seeded　at　ambient　temperature.　By　gradually　decreasing　hydraulic　retention　time　under　the　oxygen-limited　condition,　CANON　was　successfully　started-up　for　78　days.　Finally　the　MBR-CANON　system　was　adopted　for　treating　domestic　sewage,　nitrogen　and　COD　removal　achieved　to　0.97　kg　m(-3)　d(-1),　80%,　respectively,　with　the　effluent　turbidity　below　1.0　NTU.　DGGE　profiles　showed　a　distinct　community　shift　of　the　functional　bacteria　after　seeded　to　the　reactor,　and　phylogenetic　results　indicated　the　predominance　of　Nitrosomonas　and　Candidatus　Kuenenia　stuttgartiensis　for　nitrogen　removal　in　the　reactor.　FISH　results　showed　the　predominance　of　aerobic　ammonia　oxidizing　bacteria　(AerAOB)　and　anaerobic　ammonia　oxidizing　bacteria　(AnAOB)　in　the　system,　both　of　whose　proportion　reduced　when　treated　domestic　sewage.　(C)　2013　Elsevier　Ltd.　All　rights　reserved.