This　study　developed　a　two-stage　process,　including　Tetrasphaera-dominated　enhanced　biological　phosphorus-removal　(EBPR(T))　sequencing　batch　reactor　(SBR),　followed　by　sulfur　autotrophic　denitrification　(SADN)　SBR,　to　achieve　advanced　nutrients　removal　from　low　VFAs　wastewater.　The　removal　efficiencies　of　nitrogen　and　phosphorus　(PO43−-P)　reached　99　%　with　effluent　PO43−-P　and　total　inorganic　nitrogen　(TIN)　below　0.5　mg/L　and　1　mg/L　in　EBPR(T)　and　SADN　SBR,　respectively.　Mechanism　analysis　indicated　that　as　increasing　drainage　ratio　and　complex　carbon　sources,　free　amino　acids,　glycogen,　and　PHA　served　as　the　endogenous　carbon　sources　of　Tetrasphaera　to　store　energy.　SADN　contributed　to　approximately　80　%　of　nitrogen　removal.　DNA　and　cDNA　results　indicated　Tetrasphaera　was　shifted　from　clade　2　to　clade　1　after　increasing　the　drainage　ratio　and　the　complexity　of　the　carbon　source,　and　Tetrasphaera　(50.95　%)　and　Ca.　Accumulibacter　(9.12　%)　were　the　most　important　functional　microorganisms　synergized　to　remove　phosphorus　at　the　transcriptional　level　in　EBPR(T).　Thiobacillus　(45.97　%)　and　Sulfuritalea　(9.24　%)　were　the　dominant　sulfur　autotrophic　denitrifiers　at　gene　and　transcriptional　level　in　SADN.　The　results　suggested　that　the　EBPR(T)　-　SADN　SBRs　have　great　nutrient　removal　performance　in　treating　low　VFAs　wastewater　without　additional　carbon　sources.　©　2024　Elsevier　B.V.