Serratia spp. Are Responsible for Nitrogen Fixation Fueled by As(III) Oxidation, a Novel Biogeochemical Process Identified in Mine Tailings

• DOI: 10.1021/acs.est.1c06857
• Publication Date: 2022-01-10T17:13:53Z
• Authors: Yongbin Li; Lifang Guo; Max M. Häggblom; Rui Yang; Mengyan Li; Xiaoxu Sun; Zheng Chen; Fangbai Li; Xianfa Su; Geng Yan; Enzong Xiao; Haihan Zhang; Weimin Sun
• Keywords: Biogeochemical Cycle; Geomicrobiology; Serratia

Biological nitrogen fixation (BNF) has important environmental implications in tailings by providing bioavailable to these habitats and sustaining ecosystem functions. Previously, chemolithotrophic diazotrophs that dominate mine were shown use reduced sulfur (S) as the electron donor. Tailings often contain high concentrations of As(III) might function an alternative donor fuel BNF. Here, we tested this hypothesis report on BNF fueled oxidation a novel biogeochemical process addition S. Arsenic (As)-dependent was detected cultures inoculated from As-rich tailing samples derived Xikuangshan mining area China, suggested nitrogenase activity assays, quantitative polymerase chain reaction, 15N2 enrichment incubations. As-dependent also active eight other As-contaminated soils, suggesting potential for may be widespread habitats. DNA-stable isotope probing identified Serratia spp. bacteria responsible Metagenomic binning indicated essential genes [i.e., fixation, oxidation, carbon fixation] present Serratia-associated metagenome-assembled genomes. Over 20 genomes obtained NCBI contained both (i.e., aioA nifH), metabolic trait