Project types：National Natural Science Foundation of China Director：Peng Bao From 2016.01 to 2019.12 Environmental microbes drive biogeochemical cycle of the most important elements through extracellular respiration gradually attracted more and more attention. However most of the mechanisms were developed by using proteobacteria, e.g. Geobacter sulfurreducens and Shewanella oneidensis. This study focus on sulfate-reducing bacteria extracellular respiration mechanism with sulfur as electronic mediator in typical paddy fields. Field experiment, pot experiment and enrichment of anaerobic bacteria are designed as test systems, integrated application of high-throughput sequencing of large-scale, high flux protein group of quantitative technology on the basis of the transcriptome, macro proteomics method as well. The study mainly discusses the characteristics of soil solution under sulfur stress variation, solid-phase iron reduction kinetics mechanism and morphological transformation which as electron acceptor. Illuminating sulfate-reducing bacteria community structure and quantity change features under sulfur stress, then give a preliminary understanding of sulfur metabolism markers: sulfite reductase and dissimilatory adenosine-5′-phosphosulfate reductase of sulfate-reducing bacteria response to extracellular respiration at the macro transcriptome and proteome level. This research will also set up sulfate-reducing bacteria extracellular respiratory model of paddy soils through the enrichment of sulfate-reducing bacteria culture, and verify the extracellular respiratory function of sulfate-reducing bacteria enrichment. Through the above research, this study will reveal the novel microbial ecological coupling mechanisms of sulfate-reducing bacteria mediated sulfur and mental (iron) biogeochemical cycles through extracellular respiratory in paddy soils.