antimonate reducing bacteria Raw sequence reads. antimonate reducing bacteria

Microorganisms are considered to play an important role in altering antimony (Sb) speciation, mobility, and bioavailability. In this study, DNA-stable isotope probing (DNA-SIP) and metagenomics analysis were combined to identify potential Sb(V)-reducing bacteria (SbRB) and predict their possible metabolic pathways for Sb(V) reduction. Soil slurry cultures inoculated from Sb-contaminated paddy soil demonstrated a capability to reduce Sb(V). DNA-SIP identified bacteria belonging to the genera Pseudomonas, Geobacter and the family Enterobacteriaceae as putative SbRB. A shift in the relative abundance of respiratory arsenate reductase (arrA) genes to heavier DNA fractions in treatments amended with 13C-acetate and Sb(V) than those in controls suggested that the arrA genes were 13C-labeled and were likely involved in Sb(V) reduction. Near complete draft genomes (>90% completeness) of bins affiliated with putative SbRB were obtained and genes potentially responsible for As and Sb reduction (i.e., arrA and respiratory antimonite reductase (anrA)) were examined. Notably, bins affiliated with putative SbRB (i.e., Pseudomonas, Geobacter, and Enterobacteriaceae) contained arrA and anrA genes, supporting our hypothesis that they are putative SbRB. This current work represents the first demonstration of using DNA-SIP and metagenomic-binning to identify anaerobic SbRBs and the key genes for Sb(V) reduction and provides valuable datasets to link bacterial identities with Sb(V) reduction.