Effect of feeding gas type and nitrogen: Sulfur ratio on a novel sulfide-driven denitrification methane oxidation (SDMO) system

•DAMO/AD contribution for nitrate removal was positively correlation with N/S.•Biogas would develop the nitrate removal efficiency both through DAMO and AD.•HS made DAMO bacteria decrease and AD bacteria increase but LS gave little effect.•DAMO gene pmoA up-regulated under LS while other genes up-regulated under HS.