Elemental sulfur (S⁰) introduction could achieve the co-existence of heterotrophic denitrification (HDN) and autotrophic denitrification (ADN) in practical organic-limited nitrate wastewater treatment. Until now, changes in key functional species, metabolic pathways and microbial products in the succession process of microbial communities based on different of pollutant concentration and trophic conditions are still unclear. In present study, high-efficiency of total nitrogen (TN) removal achieved in S⁰-based ADN bioreactor at influent nitrate of 30–240 mg/L. Content of proteins and polysaccharides in extracellular polymeric substances (EPS) declined with nitrate loads increased. The key functional heterotrophic denitrifiers (Hyphomicrobium, Trichococcus, Rivibacter) and autotrophic biotope (Thiobacillus, Thiomonas, Ferritrophicum, Flavobacterium, Stenotrophomonas, Cloacibacterium and Pseudoxanthomonas) jointly contributed to high nitrogen removal efficiency at different nitrate loads. Furthermore, network analysis verified that symbiotic relationships accounted for the major proportion (88.3%) of the microbial network. The enhanced of nitrogen and sulfur metabolism improved nitrogen removal and S⁰-based autotrophic denitrification capacity.

在实际的有机限量硝酸盐废水处理中，引入元素硫（S ⁰）可以实现异养反硝化（HDN）和自养反硝化（ADN）的共存。到目前为止，基于污染物浓度和营养条件的不同，微生物群落演替过程中关键功能物种，代谢途径和微生物产物的变化仍不清楚。在本研究中，在进水硝酸盐为30–240 mg / L的情况下，基于S ⁰的ADN生物反应器实现了高效的总氮去除。随着硝酸盐负荷的增加，细胞外聚合物（EPS）中蛋白质和多糖的含量下降。关键功能异养反硝化菌（Hyphomicrobium，Trichococcus，Rivibacter）和自养生物小区（硫杆菌，Thiomonas，Ferritrophicum，黄杆菌属，寡养单胞，Cloacibacterium和Pseudoxanthomonas）联合促成在不同硝酸盐负荷高的氮的去除效率。此外，网络分析证明，共生关系占微生物网络的主要比例（88.3％）。氮和硫代谢的增强改善了氮的去除和基于S ⁰的自养反硝化能力。