AN INTEGRATED COMPUTATIONAL-EXPERIMENTAL APPROACH FOR ENHANCING POLLUTANT DEGRADATION IN CONTAMINATED SOILS

Microbial consortia play a vital role in all biogeochemical cycles, allowing the biodegradation of a wide range of organic and man-made pollutants to partial or full mineralization. The composition of the community and the interactions between its members affect both the rate of degradation and identity of the final products. The specific composition of a consortium is expected to vary depending on environmental conditions. Progress in sequencing technologies promotes the full description of biodiversity in ecological consortia of microorganisms. In parallel, metabolic modeling approaches are increasingly applied for simulating community function and the design of optimized degradation strategies. Here, we demonstrate the application of these approaches towards an enhanced degradation of atrazine – a herbicide causing environmental pollution, in agricultural soil. The structure of bacterial communities in atrazine treated soil was described using high-throughput sequencing. Significant changes in community composition and functional performance were associated with exposure to the herbicide. Based on differential abundance analysis, five species, with or without direct contribution to the degradation process, were chosen for modelling. Genome scale metabolic models were constructed and manually curated for these species allowing modelling of community functions. The performance of different community combinations was simulated showing variations in atrazine degrading efficiencies which correlated with co-occurrence patterns. Based on simulations we designed conditions for enhanced degradation. Conditions were tested and validated in vitro. Subsequently, we now design and test agricultural practices that will support enhanced degradation of atrazine in the field. This integrated approach aims at the development of agricultural practices, enhancing pollutant degradation.