Ecotoxicological studies traditionally focus on exposing organisms to a single stressor. However, rarely does data from such studies provide the predictive power to understand the outcome of combined stressors, which can together exacerbate, prevent or reduce the effects of the others. For example, natural environments are characterized by dynamic and complex physico-chemical parameters, which can combine with pollutants and affect residing organisms in unpredictable ways. To improve our understanding on the effects of foreign chemicals in aquatic environments, we introduce key technological advances to the field of ecotoxicology and employ them in a range of cutting-edge experiments. Key to these experiments is the conjoint examination of toxicological impacts on cellular physiologies under laboratory-engineered environments. Our main hypothesis is that perturbations in environmental parameters, like those expected to intensify due to climate change (e.g. temperature), will affect the systemic toxicity of chemicals by eliciting changes in the physiology of organisms and/or by altering the toxicity of the chemical itself. We test these hypotheses on aquatic bioindicator species, e.g. bacteria, microalgae and fish-embryos, within ‘ecotoxicology-on-a-chip’ approaches which enable us to quantitatively assess the physiological state of these organisms under combinations of chemical and environmental perturbations. The data and methods developed in this project will significantly advance our experimental abilities to test collective stress-effects and improve the prediction of chemical risks in aquatic habitats under forecasted climate change scenarios.
Funding: Vetenskapsraadet (VR), SciLifeLab
Single-cell phenotyping under relevant physico-chemical conditions
Human civilization has been built upon successive agricultural revolutions, made possible by the selection of plants for phenotypic traits that are favorable for cultivation. A similar revolution may well emerge from the selection of unicellular phototrophic organisms, such as microalgae and cyanobacteria, and their subsequent industrial use for biosynthesis of desired compounds and bioenergy production. Assisted evolution of phototrophs commonly relies on bulk cultures and is performed under standardized laboratory condition, which often hampers their use for upscaling of production processes under regular environmental conditions (e.g. in order to endure temperature fluctuations in bioreactors). In this project, microfluidic platforms are used for the photopysiological characterization and selection of single-cell phenotypes under user-controlled physico-chemical conditions. Preliminary single-cell data demonstrates that we can identify cells with elevated resilience towards rising temperatures and that selection and propagation of chosen phenotypes yields daughter populations with desired phenotypic characteristics. This highlights the potential of this technology to understand environmental change on single-cell organisms and its use for the assisted evolution of important production organisms.
Funding: Danish council for independent research (DFF)