Metabolomics insight into the influence of environmental factors in responses of freshwater biofilms to the model herbicide diuron

Abstract

Freshwater biofilms have been increasingly used during the last decade in ecotoxicology due to their ecological relevance to assess the effect(s) of environmental stress at the community level. Despite growing knowledge about the effect of various stressors on the structure and the function of these microbial communities, a strong research effort is still required to better understand their response to chemical stress and the influence of environmental stressors in this response. To tackle this challenge, untargeted metabolomics is an approach of choice because of its capacity to give an integrative picture of the exposure to multiple stress and associated effect as well as identifying the molecular pathways involved in these responses. In this context, the present study aimed to explore the use of an untargeted metabolomics approach to unravel at the molecular/ biochemical level the response of the whole biofilm to chemical stress and the influence of various environmental factors in this response. To this end, archived high-resolution mass spectrometry data from previous experiments at our laboratory on the effect of the model photosynthesis inhibitor diuron on freshwater biofilm were investigated by using innovative solutions for OMICs data (e.g., DRomics) and more usual chemometric approaches (multivariate and univariate statistical analyses). The results showed a faster (1 min) and more sensitive response of the metabolome to diuron than usual functional descriptors, including photosynthesis. Also, the metabolomics response to diuron resulted from metabolites following various trends (increasing, decreasing, U/bell shape) along increasing concentration and time. This metabolomics response was influenced by the temperature, photoperiod, and flow. A focus on a plant-specific omega-3 (eicosapentaenoic acid) playing a key role in the trophic chain highlighted the potential relevance of metabolomics approach to establish the link between molecular alteration and ecosystem structure/functioning impairment but also how complex is the response and the influence of all the tested factors on this response at the metabolomics level. Altogether, our results underline that more fundamental researches are needed to decipher the metabolomics response of freshwater biofilm to chemical stress and its link with physiological, structural, and functional responses toward the unraveling of adverse outcome pathways (AOP) for key ecosystem functions (e.g., primary production).

New sensitive tools to characterize meta-metabolome response to short- and long-term cobalt exposure in dynamic river biofilm communities

“…It is well known that contaminants can impact the (meta-)metabolome of biological systems. At 4.3 x 10 -10 M of diuron, biofilm meta-metabolomic fingerprint also began to be impacted as determined via BMD calculation on DRomics (Creusot et al, 2022).…”

Pesticides en viticulture

“…Ainsi ils représentent un risque à différents niveaux pour la santé des biofilms. En effet, une fois bioaccumulés, les pesticides peuvent causer diverses manifestations toxiques sur les différents organismes composant les biofilms, et notamment engendrer des effets délétères en étant internalisés par la cellule (Creusot et al, 2022). Selon leur mode d'action, les pesticides peuvent cibler des groupes taxonomiques différents et induire une toxicité variable selon les organismes, ce qui constitue les effets directs.…”

“…Ainsi, son application sur les communautés microbiennes parallèlement à la mesure de descripteurs physiologiques/fonctionnels et structuraux dans le cadre conceptuel de l'adverse outcome pathway (Ankley et al, 2009) pourrait permettre de faire le lien entre l'exposition et les fonctions écosystémiques portées par ces communautés, en vue de développer des descripteurs plus sensibles et précoces que ceux actuellement employés. Des travaux récents sur des biofilms ont effectivement montré une meilleure sensibilité des marqueurs métabolomiques vis-àvis des descripteurs mesurés habituellement (Creusot et al, 2022).…”

Meta-metabolomic Responses of River Biofilms to Cobalt Exposure and Use of Dose-response Model Trends as an Indicator of Effects

“…14 The whole metabolome is mainly examined using a non-targeted Liquid Chromatography-High Resolution Mass Spectrometry (LC-HRMS) 15 and is often called the metabolomic fingerprint. 16 In this approach, both unannotated and annotated metabolites are considered; the annotation consisting of assigning a tentative metabolite candidate on the basis of the mass of the ion, its retention time and its spectral fragmentation using a specific database. Metabolite responses are then often processed using multivariate statistical approach to distinguish between control and contaminant exposed group.…”