ABSTRACT: Identification of TBBPA-degraders in anaerobic bioreactor at environmentally relevant concentrations by combined protein-based stable isotope probing and metagenomics
Project description:The aim of this study was to identify TBBPA-degrading organisms in a complex microbial community by a metagenome-based functional metaproteomic approach, using protein-based stable isotope probing (protein-SIP). Firstly, the degradation kinetics were evaluated in order to simulate the decrease of residual mass of the labelled compound based on experimental data. In sequence, a metagenome was generated, and biomass was collected in different time-points for protein-SIP in incubations with 13C-TBBPA. This approach allowed for the identification organisms assimilating labelled carbon from the cometabolic degradation of a micropollutant.
Project description:Bioavailability of electron acceptors is probably the most limiting factor in the restoration of anoxic, contaminated environments. The oxidation of contaminants such as aromatic hydrocarbons, particularly in aquifers, often depends on the reduction of ferric iron or sulphate. We have previously detected a highly active fringe zone beneath a toluene plume at a tar-oil contaminated aquifer in Germany, where a specialized community of contaminant degraders co-dominated by Desulfobulbaceae and Geobacteraceae had established. Although on-site geochemistry links degradation to sulphidogenic processes, dominating catabolic (benzylsuccinate synthase alpha-subunit, bssA) genes detected in situ appeared more related to those of Geobacter spp. Therefore, a stable isotope probing (SIP) incubation of sediment samples with 13C7-toluene and comparative electron acceptor amendment was performed. We introduce pyrosequencing of templates from SIP microcosms as a powerful new strategy in SIP gradient interpretation (Pyro-SIP). Our results reveal the central role of Desulfobulbaceae for sulphidogenic toluene degradation in situ, and affiliate the detected bssA genes to this lineage. This, and the absence of 13C-labelled DNA of Geobacter spp. in SIP gradients preclude their relevance as toluene degraders in situ. In contrast, Betaproteobacteria related to Georgfuchsia spp. became labelled under iron-reducing conditions. Furthermore, secondary toluene degraders belonging to the Peptococcaceae detected in both treatments suggest the possibility of functional redundancy amongst anaerobic toluene degraders on site. 2 samples examined from the different electron-acceptors (sulphate or ferric iron) incubates at the time point of maximal toluene degradation.
Project description:In this study, we differentiated mouse ESCs via 3D aggregates called embryoid bodies in presence of environmental and human relevant TBPPA concentrations for 28 days. We collected samples at different time points and analyzed TBBPA-dependent global gene expression changes by RNA-seq. Our analyses revealed a potential TBBPA multifaceted developmental toxicity with effects on the nervous and cardiac/skeletal muscle systems. Mechanistically, our findings suggest TBBPA endocrine disrupting activities in part via prolactin signaling.