Agenda > Sessions

Session BIODEGRADATION

"The role of microbial communities in pollutant fate, distribution and degradation"

A major challenge in microbial ecotoxicology concerns our ability to evaluate the role of microorganisms in the fate of the pollutants in the ecosystems (ecodynamic concept). Individual microorganisms were shown to degrade a large spectrum of pollutants but in the environment, the biodegradation is realized by a succession of microbial organisms. The relation between chemical evidence of biodegradation and the microbial 'degraders' is generally indirect and under-studied, which makes  the prediction of the fate of pollutants in complex ecosystems difficult. Biotechnological approaches that are designed to carry out pollution remediation have received a great deal of attention in recent years, where the growing knowledge of bioremediation strategies proposed by microbial ecotoxicologists is of great interest. Biodisponibility concept is one of the challenge in biodegradation, exploring the accessibility of pollutants to biological barriers which separate microorganisms from their surrounding environment and limit their metabolization. In this session, original results facing this challenging field are welcome, and especially those at the interface between chemistry/microbiology disciplines.

Keywords: Bioremediation, Biodegradation, Biotransformation, Bioavailability, Metabolisation, Retroactive action, Ecological engineering

Keynote conference: The role of microbial communities in pollutant fate, distribution and degradation, Prof. Elizabeth A. EDWARDS, Toronto University, Canada.

Session FUNCTION

"Impact of pollutants on microbial functions"

Microbial communities support a wide range of functions in ecosystems (e.g. primary production in waters, denitrification in soils and sediments…) and thus play a key role in biogeochemical cycles. Therefore the effects of pollutants observed at microbial level can have consequences at higher level of biological organization and alter ecosystem functions. The plasticity of microbial communities supports their adaptative response to the selective pressure exerted by pollutants. Functional indicators of adaptation (e.g. tolerance acquisition) have been used as indicators of contaminant effects and linked to changes in microbial structures. During the last decade, omics techniques (metatranscriptomics, metabolomics, metaproteomics) have been widely applied to complete the information given by classical indicators.
This session will then focus on the impact of contaminants on microbial functions and the consequences at different scales: from cellular biochemical pathway to biogeochemical cycles and ecosystem functions. To cover these different scales, we invite presentations of lab studies performed at different levels of biological organization (from single-species to communities) as well as field studies. Studies at community level, exploring the impact of contaminants on community and ecosystem functions are welcome as well as studies linking functional changes with structural ones (e.g. taxonomic diversity). In this session we also intend to show the wide range of techniques developed and validated to assess microbial functions in various ecosystems, in particular this session will explore the added value of omics tools and clarify how (meta)omics tools can be combined with more classical parameters to unravel the influence of contaminants on microbial functions, especially at community level.

Keywords: Ecosystem functions, Biogeochemical cycles, Functional diversity, Microbial plasticity / adaptation, Link between functions and taxonomic diversity, Metatranscriptomics, metabolomics, metaproteomics

Keynote conference: How do aquatic microbes respond to emergent contaminants?, Dr. Fernanda CASSIO,Center of Molecular and Environmental Biology, Braga, Portugal.

Session MULTI-STRESS

"Response of microorganisms to pollutants under multi-stress conditions"

A major challenge in environmental risk assessment of pollutants lies in the establishment of causal relationships between chemical exposure and the resulting community response within complex ecosystems which are generally subjected to multi-stress conditions due to multiple chemical and/or physical pressures. To face such a challenge, there is a need to develop microbial ecotoxicological approaches to better predict and evaluate the interactions between multiple pollutants and between pollutants and other environmental parameters, which can modulate both the exposure and the sensitivity of microorganisms to toxicants.
This session will welcome original presentations about experimental and in situ studies aiming at assessing, predicting or modeling the effects of pollutants on microorganisms (at various biological levels) in a context of multiple stresses (e.g. exposure to multi-pollutant mixtures, combined exposure to pollutants and physical disturbance…). Presentations addressing the latest trends and perspectives to meet the challenge mentioned above would also be greatly appreciated.

Keywords: Pollutants vs. other environmental parameters, Exposure (including bioavailibility), Multivariate statistical analysis, Modelisation

Keynote conference: Combined chemical and non-chemical stress: towards a mechanistic understanding of stressor interactions, Dr. Mechthild SCHMITT-JANSEN, Helmholtz Centre for Environmental Research, Leipzig, Germany.

Session RISK ASSESSEMENT

"Microorganisms as a tool for a priori and a posteriori environmental risk assessment"

One of the primary objectives of ecotoxicology is to contribute to the development of innovative methods and tools for environmental risk assessment, both including predictive hazard and risk assessment as well as the in situ evaluation of environmental quality and ecotoxicological impacts in contaminated environments.
Despite the recognized importance of microbial communities in supporting a range of ecosystemic functions and services and their ubiquity in all ecosystems, microorganisms are only rarely considered in the a priori environmental risk assessment of pollutants and they are typically not protected by any regulations or legislations.
Moreover, whereas chemical analysis remains essential to assess the nature and extent of a contamination, the use of bioindicators can provide valuable complementary information on both the impact and fate of pollutants. The ubiquity of microorganisms in the environment and their capacity to adapt in many ways to a large range of pollutants make them good candidates as exposure and effects indicators, allowing them to contribute to the a posteriori environmental risk assessment.
This session will focus on the development and/or application of microbial bioindicators/biomarkers/bioassays for environmental risk assessment including pollutant availability and transfer, evaluation of environmental quality and ecological health in various ecosystems. In this session we also intend to discuss about needs and possible strategies to promote the use of microorganisms (at different levels of biological organization) in a priori and a posteriori environmental risk assessment.

Keywords: Model organisms, sentinel species, Bioavailability, Bioindication, Bioassays, Biosensors, Environmental Legislation, Quality guidelines, Indices, Monitoring

 Keynote conference: Assessing the soil microbial ecotoxicity of pesticides: Advances, limitations and new risk assessment schemes, Dr. Dimitrios KARPOUZAS, University of Thessaly, Volos, Greece.

Session TROPHIC INTERACTIONS

"Impact of pollutants on the interactions among micro- or between micro- and macro-organisms"

In many ecosystems, phototrophic organisms (including microoganisms) are at the base of “green” food webs supported by primary production while heterotrophic microorganisms play a pivotal function in detritus-based (“brown”) food webs, whatever the kind of ecosystems. Generally, the brown and the green pathways are not separated and microbial communities are playing a key role in the between-pathways interactions, which are a major determinant of ecosystem functioning.  Microorganisms are also part of living animals and plants (the ‘holobiont’ and ‘hologenome’ concept) which are no longer viewed as autonomous entities, a concept relatively new that challenged the general life science concepts. Moreover, the life of microorganisms themselves are closely linked to nutrient availability (“bottom-up control”) and to viral lysis or predation by ciliates and flagellates (“top-down control”), which control their growth and activities. Pollutants are acting at different trophic levels, and the emerging discipline of microbial ecotoxicology is now facing the challenge of evaluating the role of microbial communities in ecosystem homeostasis by considering the complex array of interactions between micro- or micro-macro-organisms and their environment under pollution pressure.
This session welcome original presentationsaddressing both the indirect effects of pollutants on living organisms and the alteration of interactions between organisms in all kinds of ecosystems (fresh or marine water, soil...) . Indirect effects could arise from modification of consumer-prey balance (top-down) or competition for resources (bottom-up) due to direct toxic pressure against one partner in the frame of community ecology. Interactions such as mutualism, cooperation, and symbiosis can be modified under pollution stress, either on one or several components of the interaction. Presentations assessing ecological modeling to predict the effects of pollutants on the interactions among micro- and between micro-macro-organisms are also fostered.

Keywords: Trophic interaction, Top-down (predation, lysis) vs. bottom-up (nutrients) controls, Host-microorganisms, Microbiota, Modelisation

Keynote conference: The complexities of pollutants and ecological interactions: Lessons from freshwater ecosystems, Dr. Rick RELYEA, Rensselaer Polytechnic Institute, Troy, NY, USA.
 

Session ECOTOXICOMIC

"EcotoxicoMic: towards an International Network on Microbial Ecotoxicology?"

Presentation and discussion around EcotoxicoMic Multidisciplinary Thematic Network.

The general objective of EcotoxicoMic Multidisciplinary Thematic Network is to improve the visibility and federate the community of microbial ecotoxicologists, with a desire to promote cross-functional actions between the ecosystems studied and between researchers belonging to different research organizations.

Keynote conference: Ecotoxicomic : A team player part of the global game in Ecotoxicology, Dr. Philippe GARRIGUES, National Center for Scientific Research, Bordeaux, France.