Project description:We developed a laboratory-scale model to improve our understanding and capacity to assess the biological risks of genetically engineered bacteria and their genetic elements in the natural environment. Our hypothetical scenario concerns an industrial bioreactor failure resulting in the introduction of genetically engineered bacteria to a downstream municipal wastewater treatment plant (MWWTP). As the first step towards developing a model for this scenario, we sampled microbial communities from the aeration basin of a MWWTP at three seasonal time points. Having established a baseline for community composition, we investigated how the community changed when propagated in the laboratory, including cell culture media conditions that could provide selective pressure in future studies. Specifically, using PhyloChip 16S rRNA gene-targeting microarrays, we compared the compositions of sampled communities to those of inoculates propagated in the laboratory in simulated wastewater conditionally amended with various carbon sources (glucose, chloroacetate, D-threonine) or the ionic liquid 1-ethyl-3-methylimidazolium chloride ([C2mim]Cl). Proteobacteria, Bacteroidetes, and Actinobacteria were predominant in aeration basin and laboratory-cultured populations. Laboratory-cultured populations were enriched in Gammaproteobacteria. Enterobacteriaceae and Aeromonadaceae were enriched by glucose, Pseudomonadaceae by chloroacetate and D-threonine, and Burkholderiaceae by high (50 mM) concentrations of chloroacetate. Microbial populations cultured with chloroacetate and D-threonine were more similar to sampled populations than thoes cultured with glucose or [C2mim]Cl. Although observed relative richness in operational taxonomic units was lower for laboratory cultures than for sampled populations, both flask and reactor systems cultured phylogenetically diverse communities. These results importantly provide a foundation for laboratory models of industrial bioreactor failure scenarios. 46 samples, flask and reactor experiments were conducted in triplicate with two exceptions: [C2mim]Cl_flask and No-Carbon_flask treatments had only one sample (no replicates).
Project description:The dataset provides the whole proteome of the anammox bacterium "Candidatus Kuenenia Stuttgartiensis" strain CSTR1 growing planctonically in semi-CSTR reactor. The bacteria were growing at high growth rate (0.33 d-1) (reactor HRT 3d).
Project description:Anaerobic ammonium oxidation (anammox) emerges as a sustainable solution for nitrogen removal in sewage, but it is susceptible to stress induced by xenobiotics that are ubiquitous in sewage. Despite wide recognition of this critical issue, a comprehensive understanding of the molecular and ecological mechanisms underlying the response of anammox consortia to xenobiotic stress remain elusive. Here, we integrated multi-omics approaches with biofilm reactor operation to unravel how bisphenol A (BPA, a representative xenobiotic) perturbs anammox consortia across environmentally relevant concentrations. We show that anammox consortia tolerated low BPA levels (0.2–2 mg/L), where nitrogen removal efficiency transiently declined and subsequently recovered, aided by a 30.9% increase in quorum-sensing (QS) signal C6-HSL. By contrast, exposure to ≥10 mg/L BPA caused severe and irreversible inhibition, with total inorganic nitrogen removal dropping to 17.8%. High BPA concentrations suppressed QS signaling, intensified oxidative stress, and compromised membrane integrity, leading to enzymatic inhibition and transcriptional repression of anammox functional genes. Multi-omics evidence revealed that BPA stress also promoted horizontal transfer of the BPA-degrading gene bisdA via extracellular DNA, suggesting a new community-level adaptive mechanism. Metagenomic and metabolomic analyses further indicated BPA-driven restructuring of microbial networks, namely high BPA levels favored denitrifiers and BPA degraders while suppressing anammox bacteria, and triggered metabolic reprogramming toward xenobiotic degradation at the expense of nucleotide and amino acid biosynthesis. Together, these findings reveal a multifaceted collapse mechanism of anammox under BPA stress, providing a mechanistic basis for designing strategies to safeguard microbial nitrogen removal in xenobiotic-laden wastewaters.