Report

Teaser, summary, work performed and final results

Periodic Reporting for period 1 - TRANSFORMER (Transformation of emerging contaminants in the aquatic environment. Fate of transformation products under multiple stress conditions)

Teaser

Imperative of TRANSFORMER was to provide understanding and gain practical knowledge on behaviour of emerging contaminants under multiple stress conditions. Likewise, project aimed in providing an integrated view of molecular events in general response of a biofilm to stress...

Summary

Imperative of TRANSFORMER was to provide understanding and gain practical knowledge on behaviour of emerging contaminants under multiple stress conditions. Likewise, project aimed in providing an integrated view of molecular events in general response of a biofilm to stress and multi-stress events. These issues, being addressed by TRANSFORMER are very important from two perspectives. One is understanding and gaining practical knowledge on the additive effects of multiple stressors because current and future rates of ecosystem response predicted on the basis of individual stressor effects may be underestimated. And the other is studying community global patterns of metabolic activity and response to stress and multi stress perturbations in order to comprehend systems-level behaviour. In summary, TRANSFORMER showed that multi-stress (i.e. flow intermittency and emerging contaminants exposure) conditions enhance biofilm biodegradation ability during short and medium term exposure suggesting indirect antagonistic relationship between drought and emerging contaminants that change water chemical status. Observed effects may suggest that, on a contrary to current believes, the short and medium term ECs biodegradation efficiency in intermittent systems may be higher. Exo-metabolome profiling demonstrates that different perturbations are immediately reflected on biofilm released metabolites. In comparison with classical biofilm descriptors the exo-metabolite response is more specific and significantly faster. Observed dissimilarity, comparing to control samples, is highest for multi-stress perturbation suggesting uppermost disturbance in molecular output for multi-stress samples.

Work performed

In order to provide an integrated view of molecular events in general response of an aquatic environment to stress and multi-stress events, TRANSFORMER performed several work tasks (described in detail by Periodic Technical Report B):
Task 1: Selection of target compounds
Task 2: Factorial design of the experiments at experimental stream facility
Task 3: Experiments at experiments at experimental stream facility
Task 4: Target and non-target analysis
Task 5: Analysis of the results

We learned that biofilm biodegradation ability is not affected by short term (4 days) exposure to a mixture of emerging contaminants. Multi-stress (i.e. flow intermittency and emerging contaminants exposure) conditions enhance biofilm biodegradation ability during short and medium term (13 days) exposure suggesting indirect antagonistic relationship between drought and emerging contaminants.
Exo-metabolome profiling demonstrated that different perturbations are directly reflected on biofilm released metabolites. The reported non-target profiling suggests immediate exo-metabolic response to intermittent flow conditions and emerging contaminats (4 days). 9 days after end of drought, however at constant presence of ECs, exo-metabolic profile is not any more influenced by drought perturbation and emerging contaminants are becoming major source of imbalance.

So far, the project results were disseminated via one paper:
Marko Rožman, Mira Petrović; Bquant - Novel script for batch quantification of LCMS data, MethodsX 3 2016 520-524. (DOI: 10.1016/j.mex.2016.09.001)
Two more papers on understanding interstressor interactions and biofilm system response to stress perturbations are in process of drafting and will be submitted once completed.
Furthermore, results are presented at the invited lecture: Transformation of emerging contaminants in the aquatic environment at Croatian Association of Freshwater Ecologist at the University of Zagreb.

Final results

TRANSFORMER addressed behaviour of emerging contaminants under multiple stress conditions. We learned that, on a contrary to current believes, the short and medium term emerging contaminants biodegradation efficiency in intermittent systems may be higher. Accordingly, this finding laid a new testable hypothesis: that river under multi-stressor conditions that combine the occurrence of pharmaceuticals with hydrological discontinuities tend to enhance biofilm biodegradation ability. In addition, our research demonstrated that different stress conditions are immediately reflected on biofilm released metabolites. The exo-metabolite response is more specific and significantly faster in comparison with classical biofilm descriptors offering possibilities for identification of extremely rapid diagnostic markers.